摘要:

Part (iii) ELECTRONIC SPECTROSCOPY By J. E. Parkin (Department of Chemistry University College London) THE appearance of the long awaited book by Herzberg’ on the electronic spectra of polyatomic molecules completes his set of volumes on fundamental aspects of molecular spectra. The treatment is as comprehensive as in the earlier volumes and besides detailed discussions of such topics as the electronic structure of polyatomic molecules the structure and analysis of rovibronic transitions and the nature of dissociative processes in electronic spectra he gives a critical compilation and assessment of spectroscopic data for molecules with between three and twelve atoms. He includes consideration of work up to the middle of 1965 and also much material publfshed since then including the year to which this report pertains.The last volume of Annual Reports (1966) contained a detailed review of the electronic spectra of polyatomic molecules by Walsh,2 which was con-cerned especially with the spectra of small molecules in particular triatomic molecules. The last report on diatomic molecular spectra by Barrow and Merer3 appeared in 1962. This report will consider a few topics relating to electronic spectroscopy in the gas phase largely supplementary to these more comprehensive reviews, which in the opinion of the author have become prominent during the last year. Rather than give it too cursory an examination in the limited format of these new Annual Reports a large field of work has been omitted entirely. Such topics as solid state and solution spectra either deserve specialist reviews or are more appropriately dealt with under a different heading.Diatomic Molecules.-The study of the molecular spectra of diatomic molecules is one of the most fruitful fields of collaboration between the theoretical chemist and the experimentalist. Not only are the systems still sufficiently simple for quantum mechanics to have considerable quantitative applicability but from the experimental point of view a very large number of diatomic combinations are sufficiently stable to provide spectroscopic informa-tion often of a very extensive nature. Several compounds of almost every element in the Periodic table have been reported and two recent examples of typical kinds of compounds are considered here. Ginter4 has reported a very detailed study of the spectrum of He,.The G. Herzberg ‘Electronic Spectra of Polyatomic Molecules’ van Nostrand New York 1966. ’ A. D. Walsh Ann. Reports 1966,44. ’ R. F. Barrow and A. J. Merer Ann. Reports 1962,99. M. L. Ginter J. Chem. Phys. 1965,42,561; 1966,45248; J. Mol. Spectroscopy 1965 17 224; 1965 18 321 206 J . E. Parkin spectrum occurs in a discharge tube from 2800 A into the i.r. region and arises from transitions between the stable Rydberg states in which a o electron is excited into Rydberg orbitals with n = 2 3 etc. In fact only the ground-state configuration lo; 10 is unstable and transitions to it from the Rydberg levels give rise to a continuum in the vacuum U.V. Fourteen states have been characterised in detail for which the excited electron is in a 2s 2pn 3s 3p0, 3d6 3dn and 3do orbital for each of which there is a singlet and triplet state.The lowest stable singlet and triplet states have for instance re = 1.0399 and 1.045081 and o = 1861.27 and 1809.91 cm.-' for AIC and a3C respectively. Mulliken and others in several recent papers (see for example Mulliken5 and references therein) have discussed in detail the properties of Rydberg states of diatomic molecules especially H and He and the behaviour of their wave-functions as the molecule approaches dissociation. The nature of the cor-relation of the molecular wavefunctions and the atomic wavefunctions of the fragments is still not entirely clear and it is evident that much remains to be done on systems even as simple as these.The high temperature King furnace has been a most prolific source of transient diatomic molecules. The two constituent elements are introduced into a graphite tube and heated electrically to temperatures up to 2600". Under suitable conditions sufficient molecules are present in many cases to allow high-resolution absorption spectra to be obtained. A large number of stable metal-metal diatomic combinations have been studied recently and precise molecular constants have been determined for several electronic states of many of them. Molecules containing gold offer a striking illustration. Recent medium-resolution studies providing vibrational information have been reported for AuCa AuSr and AuBa,6 A u G ~ ~ AuSn,8 and A U P ~ ~ and AuAs," AuSb," and AuBi.12 Ames and BarrowI3 report internuclear distances and vibrational frequencies for three electronic states of Au, the 'C; ground state has for example rz = 2.422 and 0 = 190.7 cm.-'.Ring~trom'~ gives constants for four electronic states of AuH (and also AuD) and Barrow and Travis" give constants for four electronic states of AuAl. Many other similar compounds are being reported every year and a large amount of data is accumulating. The projected data complications promised for the near future are urgently required. Since the last R e p ~ r t ~ the single most important advance in diatomic spectroscopy has been in the greater reliability of quantum mechanical calcula-R. S. Mulliken J . Amer. Chem. SOC. 1966,88 1849. J. Schiltz Ann. Physiqur 1963,8 67. M. Collette and J.Schiltz Compt. Rend. 1963,257 2092. R . Houdart and P. Carettes Compt. Rend. 1965,260 5746. l o R. Houdart and J. L. Bocquet Compt. Rend. 1967 WB 1717. R. Houdart and J. L. Bocquet Compt. Rend. 1967,264B 860. R . Houdart and J. Bocquet Compt. Rend. l966,263B 151. L. L. Ames and R. F. Barrow Trans. Faraday SOC. 1967,63,39. ' R. Houdart Compt. Rgnd. 1965,261,2609. l4 U. Ringstrom Arkiv. Fysik 1964,27,227. I s R. F. Barrow and D. N. Travis Proc. Roy. SOC. 1963,273 133 Part (iii) Electronic Spectroscopy 207 tions for ground and excited states of molecules. It now becomes increasingly easy to predict electronic energies and configurations in anticipation of and as an aid to their experimental verification. Two recent examples will be considered here. An extensive HartreeFock-Roothan treatment of the ground states of the hydrides of the first and second row of the Periodic table has been reported by Cade and Huo.16 The calculation uses a large basis set of Slater-type wavefunctions centred on the two nuclei and the molecular orbitals obtained are used to calculate experimentally determinable quantities such as the dissociation energies dipole moments and the ionisation potentials.An extensive bibliography is given for previous calculations on these systems but this is the first attempt at a systematic study of a range of molecular systems using exactly comparable calculations and so the relative magnitudes of the quantities determined are even more significant that their absolute values. Although the experimental data is largely complete for the first row hydrides, the calculations have some predictive utility for the second row hydrides where this is not the case.Of more direct spectroscopic interest is a calculation of low-lying electronic levels of the isoelectronic molecules BN and C by Verhaegen Richards and Moser.17 For C, transitions between two singlet states and two triplet states are observed experimentally. '' Their respective energies are well known and the ground state is known to be 'Z' as indeed it is in BeO another isoelectronic m01ecule.'~ For BN however the only well characterised transition is between two 311 levels although a singlet system is also known.,' It is not known which of these transitions includes the ground state. The calculations for C are in quite good agreement with experiment predicting the 'Z and 311u states to lie within 0.1 ev (although the order is reversed) and a 'nu state about 1 ev higher in energy.Similar calculations for BN predict the ground state to be 311 with other singlet and triplet states at least 0.4 ev higher. This prediction now awaits experimental verification. Triatornic Molecules.-Walsh's report2 considers triatomic molecules in some detail and many elegant investigations have appeared recently par-ticularly on free radicals and other transient species. First row dihydrides have figured prominently notably papers by Herzberg and Johns on BH ,' and CH,,, which together with earlier work on NH and OH ' comprise an inter-esting series. The lowest states of all four* are bent at equilibrium and the angles are accurately known.The higher vibrational levels in these states exhibit peculiarities in that successive intervals in the bending-vibration frequency decrease as expected until above that energy required to straighten the l6 P. E. Cade and W. M. Huo J . Chem. Phys. 1966,46 1063; 1967,47,614,649. l 7 G. Verhaegen W. G. Richards and C. M. Moser J . Chem. Phys. 1967,46 160. l9 G. Verhaegen and W. G. Richards J . Chem. Phys. 1966,45 1828. 'O A. E. Douglas and G. Herzberg Canud. J . Research 1940 MA 179. 21 G. Herzberg and J. W. C. Johns Proc. Roy. SOC. 1967 A 298 142. " G. Herzberg and J. W. C. Johns Proc. Roy. SOC. 1966 A 295,107. * Actually the lowest singlet state for CHI; the ground state is triplet and not so well characterised.E. A Ballik and D. A. Ramsay Astrophys. J. 1963,137 84 208 J. E. Parkin molecule the intervals increase. The term quasi-linearity has been proposed for this phenomenon as above the maximum in the potential-energy surface, the molecule behaves as a highly perturbed linear molecule. Johns23 has developed an earlier formalism for this situation24 and has applied it to these states as well as to a bent excited state of HCN. Using both Gaussian and Lorentzian barriers determined experimentally in a harmonic-oscillator potential he was able to account quite well for the observed dependence of the rotational constants A and the centrifugal distortion constant DK on the vibrational quantum number. PH has recently been studied extensively by Ramsay Dixon and their co-worker~.~~ The 2A,-2B transition was obtained in absorption in the visible region by flash photolysis of phosphine.Analysis of the original band at 5471 8 has shown the dihedral angle to change from 91'40' in the ground state to 123'4' in the excited state. This is sufficient to change the molecule from near-oblate symmetry (K = +0-54) to prolate symmetry (K = -0-84). This is surely the most extreme case of change in asymmetry recorded and has the effect of complicating the analysis by making allowed transitions with AK = f 3 and f 5 as well as f 1 and making branches extremely difficult to follow. In addition doublet splittings up to 9 cm.-' were identified and large centrifugal distortion corrections had to be made. Such a spectrum has only become accessible to detailed analysis with the advent of computer techniques.The analysis has since been improved slightly by Dixon and Duxbury26 who considered in greater detail the effect of centrifugal distortion on the doublet splittings. The identification of a spectrum due to ASH in the same region of the spectrum reported in a note by Dixon Duxbury and Lambert~n,~ provides an interesting series of molecules NH, PH, and ASH, and further details are awaited with interest. system of the CF radical by Mathews,' and of the 2264 8 system by Khanna Besenbruch and Margrave,' suggest they both arise from analogous 'B,-'A transitions. Both of these radicals are sufficiently long lived for their ground-state structure to be obtained accurately from the microwave spectrum and the excited state molecular parameters of CF were obtained from the electronic spectrum.In particular the CF, dihedral angle changes from 104-9' to 122.3" and the bond length changes from 1.30 to 1.32 8 on excitation. A great deal of detailed information is now available for the ground and lower excited states of these and other triatomic molecules including radicals and ions. Many of these have first been identified and characterised by their Recent analyses of the 2500 " J. W. C. Johns Canad. J . Phys. 1967,45,2639. 24 W. Thorson and I. Nakagawa J . Chem. Phys. 1960,33,994; R. N. Dixon Trans Farailay SOC., 1964,60 1363. 25 R. N. Dixon G. Duxbury and D. A. Ramsay Proc. Roy. SOC. 1967 A 296 137; B. Pascat, J-M. Berthou G. Guenebaut and D. A. Ramsay Compt. Rend.1966,263B 1397. 26 R. N. Dixon and G. Duxbury Chem. Phys. Letters 1967 1 330. '' R. N. Dixon G. Duxbury and H. M. Lamberton Chem. Comm. 1966,460. C. W. Mathews J . Chem. Phys. 1966,45,2355; Canad. J . Phys. 1967,45 1439. 29 V. M. Khanna G. Besenbruch and J. L. Margrave J . Chem. Phys. 1967,46,2310 Part (iii) Electronic Spectroscopy 209 high-resolution electronic spectrum of which recent elegant examples are the radicals CCN (Merer and Travis3') and CNC (Merer and Travis3'). A recent analysis for a singlet-singlet system of NCN by K r ~ t o ~ ~ with the earlier analysis of a triplet-triplet system by Herzberg and Travis33 is another example. Indeed the only triatomic uncharged combination of nitrogen and carbon atoms not yet identified is the NNC species. These and other recent determina-tions listed by Herzberg' demonstrate the power of the technique of flash photolysis combined with high-resolution spectroscopy in producing and facilitating the study of transient chemical species.The recent award of the Nobel prize for chemistry in part to Porter and Norrish for work fundamental to this field of study is an indication of its importance in several chemical situations. Instrumental advances on the spectroscopic side have kept pace with this work and the result is that much otherwise inaccessible information about molecular structure in excited states of mmy transient species is now being obtained. Many of these species are known to be intermediates in chemical reactions and their detailed characterisation is fundamental to understanding the mechanism of these reactions.Thrush and his co-workers for instance are conducting an interesting series of experiments on reactions between small molecules and radicals in which a detailed knowledge of the excited states of these species is of prime importance. In a recent Tilden lecture34 he discussed the mechanism of some chemiluminescence reactions in particular those of the type N + N + M + NN' + M for which the products are often electronically excited species formed with considerable efficiency. In a recent paper Clough and report on the mechanism of the reaction between nitric oxide and ozone. The chemiluminescence is due to the emission spectrum NO2 the absorption spectrum of which has most recently been investigated by Douglas and H ~ b e r .~ ~ Both excited state and ground state NO2 are formed according to the reaction schemes N0(211) + 03('A1) -+ N0,(2A,) + 02(3Z;) N0(2H) + 03('A1) + N02(2B1) + 02(3Z,) The frequency factors for the two reactions are very similar even though the activation energies differ by 1.8 kcal.mole-'. The explanation lies in the fact that both the 2 A and 2B states of NO2 are derived by Renner splitting from the hypothetical 211 ground state of linear NO2 which in turn correlates with the 211 ground state of NO. There was no evidence of electronically-excited oxygen molecules. The excited Rydberg states of polyatomic molecules are beginning to attract more detailed attention. The reasons for their comparative neglect are largely 'O A. J. Merer and D. N.Travis Canud. J . Phys. 1965,43 1795. A. J. Merer and D. N. Travis. Canud. J . Phys. 1966 44 353. '' H. W. Kroto J . Chem. Phys. 1966,44,831; Ctmad. J . Phys. 1967,45 1439. 3 3 G. Herzberg and D. N. Travis. Canad. J . Phys. 1964,42 1658. 34 B. N. Thrush Chern. in Bitain 1966 287. '' P. N. Clough and B. N. Thrush Trans. Faruday SOC. 1967,63,915. 36 A. E. Douglas and K. P. Huber Canud. J . Phys. 1965,43,74 210 J. E. Parkin experimental as transitions to them from the ground state occur in the vacuum U.V. region of the spectrum and until recently high resolution spectrographs have not been available. However the more accessible excited states of many interesting molecules are dissociative in nature and give rise to diffuse or continuous spectra whereas the Rydberg spectra are often quite sharp.The best known example of this is H201 whose first two transitions occur between 1800 and 1560 A and are continuous and very diffuse respectively. Not until the strong Rydberg transition at 1240A is a sharp electronic spectrum obtained. A recent investigation by King and Richardson37 of the spectra of the cyanogen halides ClCN BrCN and ICN follows this pattern. The first two electronic transitions of all three of these molecules are continuous while the Rydberg systems below 1700 A are quite sharp. Ground-state molecular constants are known from the microwave spectra and the excited state parameters were determined by Franck-Condon calculations on the vibrational contours observed in their vacuum U.V. spectra. With recent improvements in instrument design incorporating highly reflective gratings and mirrors for use below 2000 A and improved sources and detectors this field of study has been revitalised.Larger molecules.-The detailed spectra of large asymmetric molecules is extremely complex as is well demonstrated by a recent reinvestigation of the glyoxal n* + n transition at 4550 8 by Paldus and R a r n ~ a y . ~ ~ Typical bands are illustrated each showing many hundreds of individual rotational transitions. The task of analysing such spectra is more and more that of devising the most efficient computer techniques to accomplish the large amount of calculation associated with each line in the spectrum as well as handling the many hundreds of data to be processed. Glyoxal is still a sufficiently small molecule that indivi-dual rotational transitions are by and large resolved with modern high resolu-tion instruments.Paldus and Ramsay report an experimentally observed resolving power of 600,000 for their instrument very close to the limit imposed by the Doppler width of the glyoxal lines. Such resolution enables the congested band centres of many asymmetric-rotor molecules to be analysed in detail and the information provides precise values for the rotational constants as well as an unambiguous assignment of the band polarisation. With larger molecules still resolution of individual transition becomes impossible and only an envelope or contour is obtained. Quite often such spectra have a deceptively simple appearance as transitions may pile up preferentially in certain regions of the spectrum.Each ‘line’ however is made up from tens or even hundreds of superposed transitions and much care has to be given to their interpretation. A very useful technique evolved recently for analysis of such spectra has been termed band contour analysis.39 Briefly, trial contours are calculated from rotational constants where known from other experimental data e.g. crystallographic or microwave data and by 37 G. W. King and A. W. Richardson J . Mol. Spectroscopy 1966,21 339,353. ’* J. Paldus and D. A. Ramsay Cannd. J . Phys. 1967,45,1389. 39 J. E. Parkin J . Mol. Spectroscopy 1965 15,483 Part (iii) Electronic Spectroscopy 21 1 fitting the observed to the calculated contour by a process of intelligent trial and error improved constants may be obtained.Even using the largest and fastest modern computers such contours for a molecule like naphthalene would require about an hour of computation although several short cuts are available3' introducing relatively little inaccuracy. The largest molecule investigated in detail by this technique is naphthalene (Innes et ~ 1 . ~ ' ) whose well-known near U.V. spectrum consists of two band types polarised parallel to the two in-plane molecular axes. Contours calculated from constants derived from X-ray data for the ground state and quantum-mechanical calculations for the excited state were diagnostic in identifying the band types with certainty and by slight modification of the excited-state constants the calculated contour gave quite a precise fit to the observed type43 contour.The constants determined in this way provide some justification for the quantum-mechanical calculations although much more work is needed to determine complete molecular geometries. Free Radicals.-Although the field of triatomic free radicals is legion, relatively few radicals with four or more atoms are well characterised from their electronic spectrum. Spectra of vinoxy41 (CH,CHO) pr0p-2-ynyl~~ (CH,CCH), and a l l ~ l ~ ~ (CH,CHCH,) have been reported recently but the last two are quite diffuse and not amenable to high resolution investigation. The iso-electronic radicals BOF and F,CN have been studied recently in detail. The former was obtained by mat hew^^^ using a microwave discharge in BF and 0 vapours and the latter by Dixon et by flash photolysis of CF,N=CF,.In both cases band-contour analyses were used to provide positive identifica-tion of the emitting species the band type and the rotational constants. These were consistent with planar structures for both molecules. Several other emitting species were present in both systems and it is surely only a matter of time before the spectra of many other interesting polyatomic radicals are discovered. Aromatic Molecules.-Several high-resolution analyses of aromatic mole-cules have been reported during the past year. The spectrum of benzene itself in the region of 2600 A has been reinvestigated in considerable detail by Callomon Dunn and Mills.46 Many of the bands have a characteristic con-tour dependent on the rotational constants and Coriolis coupling coefficients.The contours were used to reassign many of the bands and to determine molecular parameters. The electronic origin the transition which is forbidden by the selection rules was calculated to be at 38,086.1 cm.-l The rotational constants gave an estimate of the increase in the C-C bond length on excitation 40 K. K. Innes J. E. Parkin D. K. Ervin J. M. Hollas and I. G. Ross J . MoZ. Spectroscopy 1965, 4L D. A. Ramsay J . Chem. Phys. 1965,43,518. 42 D. A. Ramsay and P. Thistlethwaite Canad. J . Phys. 1966 44 1381. 43 C. L. Currie and D. A. Ramsay J . Chem. Phys. 1966,45,488. 44 C. W. Mathews J . Mol. Spectroscopy 1966,19,203. 45 R. N. Dixon G. Duxbury R. C. Mitchell and J. P. Simons Proc. Roy. SOC. 1967 A 300,405. 46 J. H.Callomon T. M. Dunn and 1. M. Mills Phil. Trans. 1966 259,499, 16 406 212 J . E. Purkin to be 0.038 A in excellent agreement with estimates from other sources. This electronic system is the prototype transition for a large rlumber of spectra of aromatic molecules and is the rock upon which many theories of molecular structure are based. The authors give considerable attention to evaluating how much of the current description of this system is firmly based and how much is still intelligent conjecture. The introduction of heteroatoms into the benzene ring gives R* t n transi-tions in addition to the n* +- R benzene-like transitions above. In a very useful review article Innes Byrne and Ross47 give a critical summary and assessment of the spectral data for the six known azine molecules pyridine, pyrazine pyrimidine pyridazine s-triazine and s-tetrazine.A large amount of data on these molecules has accumlated interest centring on the ground states and n* + n transitions in the visible and near U.V. region of the spectrum. Both singlet and triplet systems are known in most cases and many interesting features have emerged from their detailed study. Very recently Merer and Innes4' have reported a detailed analysis of the 5515 A system of s-tetrazine. Rotational analyses of six different isotopic modifications have provided structures for both the ground 'A, state and excited 'B3 state. The ground state appears not to be greatly distorted from hexagonal structure as X-ray data has suggested while on excitation the N-N bond lengths are reduced by 0.11 A and the separation of the carbon atoms increases by 0-10 A.This behaviour is difficult to account for in simple molecular-orbital terms. A rotational analysis of the phenol spectrum which consists of a system of Innes and Parkin,49 making much use of band-contour calculations has demonstrated elongation of the molecule on excitation. Brand and his co-workers have recently published comprehensive analyses of the near U.V. spectra of aniline (2940 A) and phenol (2750 A) both in absorption. Brand Williams and Cooks0 have shown that the out-of-plane NH bending vibration in the ground state of aniline is strongly anharmonic, characteristic of a double minimum potential. The NH group is some 46" out-of-plane at equilibrium. The upper electronic state also appears to have an anharmonic potential for this vibration but is not nearly so marked.Vibrational analyses are presented for four isotopic species of the molecule. Bist Brand and Williams" have presented a very detailed vibrational and rotational analysis of the phenol spectrum which consists of a system of strong allowed type-B bands with weaker type-A bands. Band-contour analyses again allowed rotational constants to be determined besides identi-fying the band types. The transition appears to be the analogue of the 2600 A transition in benzene and in the ground state the molecule appears to deviate little from benzenoid character. On excitation however it appears to gain some 47 K. K. Innes J. P. Byrne and I. G. Ross J . Mol. Spectroscopy 1967,22 125.48 A. J. Merer and K. K. Innes Proc. Roy. SOC. 1968 A. 302 271. 49 K. K. Innes and J. E. Parkin J . Mol. Spectroscopy 1966,21,66. 50 J. C. D. Brand D. R. Williams and T. J. Cook J . Mol. Spectroscopy 1966,20,359; 1966,20,359. 5 1 H. D. Bist J. C. D. Brand and D. R. Williams J . Mol. Spectroscopy 1966,21,76; 1967,24,413 Part (iii) Electronic Spectroscopy 213 quinonoid character on the bais of an elongation of the ring and an increase of some 3.5 times in the OH torsional barrier. The Stark Effect in Electronic Spectroscopy.-The Stark splitting of rotational transitions upon application of an intense electric field has long been used as a standard technique in microwave spectroscopy both for assignment and for ground-state dipole-moment determination.Application to rovibronic spectra has been limited by inadequate resolution. Recently Buckingham and RamsayS2 have described a technique of Stark modulation in electronic spectra by which they were able to produce ‘P-branches and ‘Q-branches selectively in the 3370 8 band of formaldehyde in respectively parallel and perpendicular polarisation of the absorbing light with respect to the electric field. They were thus able to achieve a considerable simplification of the spectrum as an aid to analysis. Unfortunately the tech-nique has yet to be applied successfully to a spectrum not previously analysed. Bridge Haner and DowsS3 using a different technique have shown how the relatively diffuse spectrum of acrolein at 3865 A studied earlier by Holla~,’~ is considerably sharpened in the electric field spectrum.New rotational structure was observed in a large number of bands and the task of vibrational analysis especially in the identification of hot bands was much simplified. Further application of these techniques is awaited with interest. Klemperer and his co-workers have used static fields to determine excited-state dipole moments for a number of molecules. The dipole moment of formaldehyde in the ‘ A excited state was found by Freeman and Klemperer’’ to be 1-56 & 0.07 D in the same sense as the ground state moment of 2-34 Ifi: 002 D. In another experiment Lombardi Freeman and KlempererS6 were able to show conclusively that the Stark splittings in the 3480 8 band of formaldehyde in polarised radiation were consistent only with magnetic-dipole selection rules confirming an earlier conclusion of Callomon and Inne~.’~ Freeman Lombardi and Klemperer” have determined the pa com-ponent in the ‘A” excited state of propynal to be 0.7 f 0-2 D the ground-state value being 2-39 0.04 D.Unfortunately the p b component is experimentally inaccessible (ground state p b = 0-6 & 0.1 D) and so the large change in pa on excitation may not be too significant. Lombardi Campbell and Klemperer” find the dipole-moment components of formyl fluoride in the ‘A” excited State to be pa = 1-66 Ifr 0.01 D p b = 2-0 + 05 or -1.0 D compared with the ground-state values of 0.595 D and 1.93 D respectively. They find these results difficult to account for in simple molecular-orbital terms and the data should be very useful in theoretical studies of this molecule.5 2 A. D. Buckingham and D. A. Ramsay J . Chem. Phys. 1965,42 3721. 5 3 N. J. Bridge D. A. Haner and D. A. Dows J . Chem. Phys. 1966,44,3128. 54 J. M. Hollas Spectrochim. Acta 1963 19 1425. 5 5 D. E. Freeman and W. Klemperer J . Chem. Phys. 1964,40,604; 1966,45 52. 56 J. R. Lombardi D. E. Freeman and W. Klemperer J . Chem. Phys. 1967,46,2746. 57 J. H. Callomon and K. K. Innes J . Mol. Spectroscopy 1963,10 166. ’* D. E. Freeman J. R. Lombardi and W. Klemperer J . Chem. Phys. 1966,45 58. J. R. Lombardi D. Campbell and W. Klemperer J . Chem. Phys. 1967,46,3482. 5 214 J . E. Parkin Photoelectron Spectroscopy.-The last few years has seen the rapid develop-ment of the technique of photoelectron spectroscopy as a tool for investigation of the electronic properties of molecules.Essentially an application of the photoelectric effect to gases high-energy monochromatic radiation (He 584 A, 21-21 ev) is absorbed by the gas and the energy spectrum of the ejected electrons is measured with a suitable analyser. Much work has been done on the im-provement of analyser design in order to obtain optimum resolution. Turner6' reports a recent design using deflection of the electrons in a radial electrostatic field by which a resolution E/AE of 450 was observed. At 9 ev this corresponds to a separation of 0.02 ev or 160 cm.-' sufficient to resolve the vibrational structure of small molecules and indeed Turner6' reports shading of four vibrational bands of the O l ,llg O, X3Xg- ionisation process by rotational broadening attributable to the large change in bond length re from 1.2076-1-1127 A.Diatomic molecules have been prominent in the early studies and also more recently with higher resolution instruments. Notably Turner and May6' have measured several ionisation potentials for H, N, COY O, and NO. Detailed studies of the vibrational pattern associated with each ionisation process enable the bonding character of the electron removed to be deduced by quantitative use of the Franck-Condon principle. For 0 for instance 4 ionisation potentials are obtained at 12.08 ev (,ng) 16-12 ev ("nu) 18-17 ev (4Xg-) and 20.29 ev ("X?). Wacks6 and Halmann and L a ~ l i c h t ~ ~ have calcu-lated Franck-Condon factors for ionisation processes in oxygen and several other diatomic molecules and the observed vibrational contours are in very good agreement with the calculations.The large change in bond length on excitation to the "nu state of 0; (Are = + 0.1737 A) results in a long vibrational progression of over 13 members (although some of the structure may be due to the 211u state expected but not positively identified in this region) while the 'IIg state gives rise to only 4 progression members (Are = -0.0949 A). The 411u state arises by removal of a bonding n,2p electron whereas the 211g state arises by removal of an antibonding ng2p electron the relative bonding characteristics of which are reflected in the extent of the Franck-Condon contour. The triatomic molecules CO, OCS CS2 and N 2 0 have been analysed at high resolution by Turner and May,64 following earlier work by Al-Jaboury, May and Turner.65 For COZY ionisation potentials were measured at 13.79, 17.32 18.07 and 19.38 ev.The first of these corresponds to the ,IIg ground state of CO,' by removal of a 17tg electron and has very little vibrational struc-ture associated with it. The second has some vibrational structure attributed to a progression in v1 (1131 cm.5 I) and corresponds to the state of CO,' 6o D. W. Turner Nature 1967 213 795. 6 1 D. W. Turner and D. P. May J . Chern. Phys. 1966,45,471. b L M. E. Wacks J . Chern. Phys. 1964,41,930 63 M. Hallmann and I. Laulicht J . Chem. Phys. 1965 43 1503. 6 A D. W. Turner and D. P. May J . Chem. Phys. 1967,46 1156. M. I. Al-Joboury D. P. May and D. W. Turner J .Chern. Soc. 1965 6350 Part (iii) Electronic Spectroscopy 21 5 by removal of a strongly bonding 171 electron. Again calculated Franck-Condon factors were shown to be in good agreement with the experimental results. N20 provides 4 ionisation potentials at 12-90,16-40,17-66 and 20.28 ev all of which show some vibrational structure. The third of these has not been observed before and indeed its photoelectron spectrum is considerably weaker than the others. OCS and CS provide 4 and 5 ionisation potentials respectively, but show little evidence of vibrational structure in their spectra. From a comparison of the photoelectron spectra of water and methanol, and methane and ethane Al-Joboury and Turner66 have revised the orbital assignments of methanol and ethane the highest occupied orbitals in the latter being antisymmetric C-H bonding rather than symmetric C-C bonding.Brundle and Turner67 give 5 ionisation potentials for formaldehyde of 10-8,13.99,15436,16-6 and 20.5 ev. The first of these corresponds to removal on a non-bonding oxygen electron. The second and third systems show well-developed vibrational structure and by comparison with the spectrum of deuteriated formaldehyde the authors conclude that they correspond to removal of a 7c-electron and a C-H o-electron respectively. Clark and Frost68 have measured the ionisation potentials of a series of fluorobenzenes and benzene itself (see also Al-Joboury and Turner69) and attempt to correlate them using simple Huckel theory. The first ionisation at 9.25 ev for benzene is generally accepted to correspond to removal of a n-electron.The second however at 11-49 ev for benzene is the subject of some controversy Clark and Frost68 assigning it to removal of a n-electron while Dewar and Kelemen,” on the basis of more accurate SCFMO calculation, assign it to removal of a o-electron. Turner71 has remeasured the spectrum of benzene pyridine and hexafluorobenzene at higher resolution and notes that the appearance of marked vibrational structure in this band argues in favour of 7c-electron removal. It may be seen from these few examples that photoelectron spectroscopy has a very wide application to chemical problems. The promise of a com-merical instrument for the near future will mean that yet another tool will be added to the chemist’s repertoire. 66 M. I. Al-Joboury and D. W. Turner J . Chem. SOC. (B) 1967,373. 67 C. R. Brundle and D. W. Turner Chem. Comm. 1967 314. 6 8 1. D. Clark and D. C. Frost J . Amer. Chem. SOC. 1967,89 244. 69 M. 1. Ai-Joboury and D. W. Turner J . Chem. SOC. 1964,4434. ’O M. J. S. Dewar and J. Kelemen Tetrahedron Letters 1967 35 2341. 71 D. W. Turner Tetrahedron Letters 1967 35 3419

ISSN:0069-3022    

DOI:10.1039/GR9676400205

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

INORGANIC CHEMISTRY INTRODUCTION THE first new-style Annual Reports on Inorganic Chemistry do not differ much in form from those of previous years. There are two reasons for main-taining something like the old arrangements at least for this year. First it seems that this arrangement of reports has made it possible for many readers to find particular pieces of information fairly easily; the-coverage of the subject has been much more nearly on an annual basis than in Physical Chemistry. Second few of the specialist reports on inorganic subjects have yet been commissioned; until they are under way there is a strong argument for retaining the coverage provided by the old reports. As in previous years, the reports here by no means represent a comprehensive coverage of pub-lished material; the volume of published work continues to increase and two new journals of particular interest to inorganic chemists,-Inorganica Chimica Acta and Spectroscopy Letters-have appeared.It seems that something like one out of five of the papers considered by reporters has been cited. The choice is naturally arbitrary and selective; it is hoped nevertheless, that these reports contain the most significant work published during the year and also indicate the directions in which the subject has been developing most rapidly. Some of the additional space has been used to give rather more in the way of explanation and discussion than was possible in previous years; the style at times in the past necessarily telegraphic is a little less compressed. Thus these reports represent something of a comparison between the old and what was envisaged as proper for the new. There have been no spectacular advances in the subject as a whole. Work has continued on complexes of transition metals with molecular gases such as 02 N and H, and there has been further expansion in the fields of organo-metallic chemistry and of the chemistry of compounds containing metal-metal bonds. But the general pattern of progress in the subject has been one by advance on a relatively broad front coupled with the mopping-up of isolated pockets of resistance behind the front line rather than by the making of any important new breaches in the frontiers of ignorance

ISSN:0069-3022    

DOI:10.1039/GR9676400217

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

11. THE TYPICAL ELEMENTS By A. J. Downs (Inorganic Chemistry Laboratory South Parks Road Oxford) G. M. Sheldrick and J. J. Turner (University Chemical Laboratory Lensfield Road Combridge) THE chemistry of the typical elements has been notable in the year under review not for outstanding advances but for the continued development and consolidation of known areas of research. In matters of interpretation familiar controversial issues such as d-orbital participation and n-bonding have been no less ubiquitous ; significantly therefore calculated valence-state energies of later second-row elements suggest that the importance of the 3d orbitals has in the past been overrated.’ The limitations of any classification of inorganic donors and acceptors have been underlined in a critical review quantitative measures of donor-acceptor interactions have been proposed,2b principally with the aim of evaluating ‘hardness’ and ‘softness.’ The solvation of species in non-aqueous solvents has been discussed in terms of the free energy of ionic transfer,2c and of the ‘donor number’ of the solvent,2d a concept which has now been described in more detail.There have been two reviews of systems involving high co-ordination number^,^" as well as an up-to-date account of electron-pair repulsion theory,3b and a discussion of the intramolecular racemisation of optically active five-co-ordinate ~ t r ~ c t ~ r e s . ~ ~ In addition to new books about free details have appeared of some e.s.r. studies of free radicals like SO C10 and BrO in the gas phase.4c Studies of hydrogen bonding include crystallographic analysis of some salts M’HX (HX = MeC02H PhCH,*CO,H etc.) with very short 0---H---0 distances of 2.43-2.46 A ;’’ perturbation calculations suggest that stable A-H---B hydrogen bonds may be formed even when A-H is non-polar.5 b Organometallic compounds are well served both by P. Palmieri and C. Zauli J. Chem. SOC. (A) 1967,813. (a) R. J. P. Williams and J. D. Hale Structure and Bonding 1966,1,249; (b) A. Yingst and D. H . McDaniel Inorg. Chem. 1967 6 1067; M. Misono E. Ochiai Y. Saito and Y. Yoneda J. Inorg. Nuclear Chem. 1967,29,2685; R. S. Drago Chem. in Britain 1967,3,516; (c) R. Alexander E. C. F. KO, Y. C. Mac and A. J. Parker J. Amer. Chem. SOC. 1967,89,3703; (d) V. Gutmann and E. Wychera, Rev. Chim.minkrule 1966 3 941. ’ (a) R. F. Hudson Angew. Chem. Internat. Edn. 1967 6 749; E. L. Muetterties and C. M. Wright Quart. Rev. 1967 21 109; (b) R. J. Gillespie Angew. Chem. Internat. Edn. 1967 6 819; (c) E. L. Muetterties Inorg. Chem. 1967 6 635. (a) P. W. Atkins and M. C. R. Symons ‘The Structure of Inorganic Radicals,’ Elsevier Amster-dam 1967; (b) G. H. Williams ‘Advances in Free-radical Chemistry,’ Logos and Academic Press, London vol. I 1965; vol. 11,1967; (c) A. Carrington and D. H. Levy J . Phys. Chem. 1967,71,2. ’ (a) J. C. Speakman Chem. Comm. 1967,32; (b) F. B. van Duijneveldt and J. N. Murrell J . Chem. Phys. 1967.46 1759 220 A. J . Downs G. M . Sheldrick and J . J . Turner volumes 1 4 of a new series,‘” and by volume 1 of a recast edition of Coates’ ‘Organometallic Compounds ;”’ reviews have also been published on the influence of co-ordination on the reactivity of organometallic compounds,‘“ and on organometallic pseudo-halides.6d Some publications dealing with more technical aspects are noteworthy.Thus reviews7“ and a data index7’ of Mossbauer spectroscopy have appeared. Mass spectrometric studies of inorganic systems at high temperature have been reviewed ;7c the analysis of mass spectra due to species containing more than one polyisotopic element7d and a new index and bibliography of mass spectra7= have also been published. The photoelectron spectrum observed when an atom in a compound is irradiated with X-rays furnishes a new and potentially valuable source of structural i n f ~ r r n a t i o n . ~ ~ A collection of bond energies ionisation potentials and electron affinities has appeared,8” as has a new book about tritium and its compounds.8b Group 0.-The most significant advances in noble-gas chemistry have been preparative i.r.spectra of the condensed ( 2 0 ” ~ ) products of a microwave discharge in a xenon<hlorine gas mixture give strong evidence for linear, symmetrical XeCl ;9 mixing ice-cold aqueous solutions of XeO and CsCl produces shock-sensitive crystals of CsClXeO ;lo XeO reacts with liquid XeOF to produce a homogeneous liquid mixture fractional distillation of which gives colourless crystals of XeO,F, preliminary vibrational spectra indicating C, symmetry with approximately linear F-Xe-F :‘la there is mass-spectral evidence for the preparation of XeO,F from XeF and Na,XeO,.”b A monograph .m the noble gases has been published.12 Aqueous solutions of XeF contain at least 97 % molecular XeF2 ;13” the effects of pH, ionic strength and different ions on the hydrolysis of XeF have been~tudied.’~~ In the reaction of XeF and XeO in aqueous solution H20214aib (and XeO, (a) A.N. Nesmeyanov and K. A. Kocheshkov ‘Methods of Elemento-organic Chemistry,’ vol. 1 4 North-Holland Amsterdam 1967; (6) G. E. Coates and K. Wade ‘Organometallic Com-pounds. Vol. 1. The Main Group Elements,’ Methuen London 1967; (c) 0. Yu. Okhlobystin Russ. Chem. Reo. 1967,36 17; (d) J. S. Thayer and R. West Ado. Organometallic Chrm. 1967,5 169. ’ (a) V. I. Goldanskii Angew. Chem. Internat. Edn. 1967 6 830; N. N. Greenwood. C h m . in Britain 1967 3 56; R.H. Herber Progr. Inorg. Chem. 1967,8 1 ; (b) A. H. Muir jun. K J AnJo, and H. M. Coogan ‘Mossbauer Effect Data Index 1958-1965,’ Interscience New York and London, 1966; (c) J. Drowart and P. Goldfinger Angew. Chem. Internat. Edn. 1967,6 581; (d) A. Carrick and F. Glockling J. Chem. SOC. (A) 1967,40; (e) F. W. McLafferty and J. Pinzelik ‘Index and Bibliography of Mass Spectrometry 1963-1965,’ Interscience New York and London 1967; cf) See e.g. A. Fahlman, K. Hamrin J. Hedman R. Nordberg C. Nordling and K. Siegbahn Nature 1966 210 4. (a)’V. I. Vedeneyev L. V. Gurvich V. N. Kondrat’yev V. A. Medvedev and Ye. L. Frankevich, ‘Bond Energies Ionisation Potentials and Electron Affinities,’ Edward Arnold London 1966 ; (b) E. A. Evans ‘Tritium and its Compounds,’ Butterworth London 1966.L. Y. Nelson and G. C. Pimentel Znorg. Chem. 1967,6 1758. (a) J. L. Huston J. P h p . Chem. 1967,71,3339; (b) J. L. Huston Znorg. Nuclear Chem. Letters, l o B. Jaselskis T. M. Spittler and J. L. Huston J . Amer. Chem. SOC. 1967,89 2770. 1968,4 29. l 2 H. H. Claassen ‘The Noble Gases,’ D. C. Heath Boston 1966. l 3 (a) E. H. Appelman lnorg Chem. 1967,6 1268; (b) M. T. Beck and L. Dbzsa J . Amer. Chem. l4 (a) E. H. Appelman Znorg. Chem. 1967,6 1305; (b) P. Allamagny and M. Langignard Bull. SOC. 1967,89 5713. SOC. chim. France 1967,3630 The Typical Elements 22 1 Xe0,14a) has been proposed as an intermediate. The H,XeO,-XeO couple has been corrected" from 3.0 to 2.3 v. There is no evidence for the formation of XeO and XeO in mass spectral studies on xenon oxides.16 Raman spectra of XeF s ~ p p o r t ' ~ " a non-octahedral gas phase structure and the significance of XeF electron diffraction results has been d i s c ~ s s e d .' ~ ~ The details of the crystal structure of [xeF5]+[PtF6]- have been published.'* New complexes prepared include XeF2,21F,,' 2XeF,,AsF, 2XeF6,PF5,'9b 4XeF6,GeF4, 2XeF,,GeF, and XeF,,GeF, but XeF does not react with SiF,.'"' Group 1.-Articles concerning the physical and chemical properties of the alkali metals are contained in a new book.20a The properties of liquid sodium have been reviewed ;,Ob from preliminary results a direct correlation is apparent between the liquidus curve for a binary metal solution (e.g. Na-Ba) and its chemical reactivity.,Oc Compressibility data for alkali metal (M) vapours at high temperature imply the formation of M as well as M,; equilibrium constants and enthalpies of association have been evaluated.20d For alkali-metal solutions in amines or amine-ammonia mixtures the dependence of the e.s.r.spectrum upon the nuclear spin configuration and concentration of the metal are interpreted2l0 in terms of additional equilibria involving both the para- and dia-magnetic species. The equilibrium constants measured21b for the processes : ea& + NH + NH + $H2 Na' + eim + NH + NaNH,(s) + $H, (1) (2) are (1) 5 x lo4 and (2) 3 x lo9 at 25"c. Kinetic studies of the bleaching of sodium solutions in liquid ammonia by alcohols or water confirm21c that the reaction : e - + H,O - Ha + OH-, is relatively slow under these conditions.According to the 'H and 'Li n.m.r. spectra22a of mixtures of organo-lithium E. H. Appelman and J. G. Malm J . Amer. Chem. SOC. 1967,89 3665. M. H. Studier and J. L. Huston J . Phys. Chem. 1967,71,457. l 7 (a) E. L. Gamer and H. H. Claassen Inorg. Chem. 1967 6 1937; (b) L. S. Bartell J . Chem. Phys. 1967,46,4530. N. Bartlett F. Einstein D. F. Stewart and J. Trotter J . Chem. SOC. ( A ) 1967 1190, l y ( a ) H. Meinert G. Kauschka and St. Rudiger 2. Chenl. 1967,7 1 I 1 ; (b) K. E. Pullen and G. H. Cady Inorg. Chem. 1967,6 1300; (c) ibid. p. 2267. 2o (a) 'The Alkali Metals,' Chem. SOC. Special Publ. No. 22 1967; (b) C. C. Addison Endeavour, 1967 26 91; (c) C. C. Addison B. M. Davies R. M. Lintonbon and R. J. Pulham Chem. Cornrii 1967,211; (4 C.T. Ewing J. P. Stone J. R. Spann and R. R. Miller J . Phys. Chern. 1967,71,473. 21 (a) R. Catterall M. C. R. Symons and J. W. Tipping J . Chem. SOC. (A) 1967 1234; (b) E. J. Kirschke and W. L. Jolly Inorg. Chem. 1967,6,855; ( c ) R. R. Dewald and R. V. Tsina Chem. Comm., 1967,647. 22 (a) L. M. Seitz and T. L. Brown J . Amer. Chem. SOC. 1967 89 pp. 1602 1607; S. Toppet, G. Slinckx and G. Smets J . Organometallic Chem. 1967,9,205; (b) R. Waack M. A. Doran and E. B. Baker Chem. Comm. 1967 1291; (c) P. West and R. Waack J . Amer. Chem. SOC. 1967,89 4395; (a) M. Schlosser and V. Ladenberger J . Organometallic Chem. 1967,8 193 ; (e) G. Kobrich Angew. Chem. Internat. Edn. 1967,6,41; v) A. I. Shatenshtein and E. S. Petrov Russ. Chem. Rev. 1967,s. loo 222 A. J. Downs G.M . Sheldrick and J . J . Turner compounds RLi (R = Me Et or Ph) with derivatives of the type MR, (M = Mg Zn Cd or Hg) complexes with the composition Li2MR (M = Mg or Zn) and LiMR (M = Mg Zn or Cd) are formed in ether solution. In the systems MeLi-Ph,Mg and PhLi-Me,Mg phenyl groups tend to reside on the complex here of the form Li,MgMe,_,Ph, in preference to species such as Li,Me,Ph. Similar experiments with ether solutions of organo-lithium compounds and lithium halides demonstrate22b the formation of mixed aggregates of RLi and LiX. In tetrahydrofuran (THF) or ether the degrees of aggregation of MeLi PhLi and PhCH,Li are 4,2 and 1 respectively according to colligative measurements22c at 25". By the exchange between Bu"Li and aryl iodides in a hydrocarbon solvent22d aryl-lithium compounds are con-veniently prepared.a-Halogenoorgano-lithium compounds,22e important as carbenoid reagents and the influence of solvents on the formation and proper-ties of alkali-metal-aromatic hydrocarbon complexes22f have been the subjects of review articles. X-Ray powder techniques indicate, a tetrameric cubane-like unit for the t-butoxides of potassium rubidium and caesium. Recent crystallographic studies of some lithium halide complexes with nitrogen bases have shown2 that LiCl,(C,H,N),,H,O has the structure of an essentially molecular adduct. The i.r. spectrum of the vapour species above LiF trapped by matrix-isolation techniques is inter~reted,~ in terms of the LiF Li,F2 and Li,F molecules; isotope shifts are consistent with a planar cyclic structure for Li,F, while a cyclic structure is also favoured for Li,F,.As judged by electric deflection studies of molecular beams,26 Cs,O is polar, and therefore in contrast to Li,O presumably non-linear an anomaly which contravenes the simple ionic model; the Cs2S04 C S ~ and Cs,(OH), molecules are non-polar. Group 11.-Monomeric diphenylberyllium complexes Ph,Be,L (L = tetra-methylethylenediamine tetramethyl-o-phenylenediamine 1,2-dimethoxyeth-ane and 2,5-dithiahexane) are described ;27a complexes of the type Ph,Be,L, at 0" have negligible dissociation pressures when L = Me,O Me,S and Me,P, but have appreciable dissociation pressures when L = Me,N and Et,O. With secondary amines Ph,Be eliminates benzene27" to give products such as (PhBe,NMe,) and (PhBe,NPh,), which are formulated with three-co-ordinate beryllium.This type of geometry has been verified27b in the trimeric unit of crystalline bis(dimethy1amino)beryllium (l) wherein the planarity of the terminal C,N-Be units the short Be-N bonds and the l3C-H coupling constant of the terminal NMe groups may bespeak Be-N pn - pn bondinp. 23 E. Weiss H. Alsdorf and H. Kiihr Angew. Chem. Internat. Edn. 1967,6 801. 24 F. Durant P. Piret and M. van Meerssche Acta Cryst. 1967 22 52. 23 A. Snelson J . Chem. Phys. 1967,46 3652. 26 A. Biichler J. L. Stauffer and W. Klemperer J . Chem. Phys. 1967,46 605. 27 (a) G. E. Coates and M. Tranah J . Chem. SOC. (A) 1967,236; (b) J. L. Atwood and G. D. Stucky, Chem. Comm. l967,1169;(c)G. E. Coates and M. Tranah J . Chem.SOC. (A) 1967,615; (d) G. E. Coates and A. H. Fishwick J . Chem. SOC. (A) 1967 1199; (e) G. E. Coates P. D. Roberts and A. J. Downs, J . Chem. SOC. (A) 1967 1085; v) A. Haaland quoted in ref. qb) p. 108; (9) E. C. Ashby R. Sanders, and J. Carter Chem. Comm. 1967 997; (h) W. Strohmeier W. Haecker and G. Popp Chem. Ber., 1967,100,405 The Typical Elements 223 The organo-beryllium hydride complexes RBeH,NMe3 (R = Me or Ph) and PhBeH,PMe, are described;27c the trimethylamine complex with R = Ph is dimeric in benzene. It is concluded27d that a balance between entropy angular valence strain and steric effects determines whether aminoberyllium alkyls RBeNR' are di- or tri-meric [(2a) or (2b)] in solution; small groups R and R' / NP'2 "6; RBe BeR (2a) (2b) lead to trimers but increasing the size of R and particularly R' favours dimer formation.From aminoberyllium alkyls the complexes [RBe(NR;) py],, RBe(NR',)py (R = Me R' = Me; R = Me R' = Ph; py = pyridine) and RBe(NPh,) bipy (R = Me or Et ; bipy = 2,2'-bipyridyl) have been prepared.27d Steric congestion is presumably responsible for the monomeric nature of [Me,C],Be in the liquid and vapour phases;27" the vibrational spectrum is consistent with a linear C-Be-C skeleton a conclusion supported by electron diffraction of the ~ a p o u r ~ ~ f which discloses a Be-C bond length of 1.699 0.004A. On the evidence of n.m.r. spectra ebullioscopic data and selective precipitation experiments the redistribution : Me,Be + BeBr + 2MeBeBr, occurs in ether solution ;27g by contrast radioactive tracer studies previously indicated no redistribution in the Ph,Be-BeBr system.Quaternary ammonium halides like alkali fluorides with diethylberyllium to form complexes R4NX,2BeEt (E = Me Et or a combination of PhCH and Me; X = F or C1) ; thermal decomposition of certain of these complexes e.g. NMe4F,2BeEt,, in uucuo at ca. 120" gives pure ether-free diethylberyllium. In benzene at 80" dissociation occurs :27h MX,2BeEt2 + MX,BeEt + BeEt,, notably when MX = KF or RbF. 224 A. J . Downs G. M . Sheldrick and J . J . Turner The constitution of Grignard reagents under different conditions and the mechanisms of some of their reactions have been reviewed.28“ Ebullioscopic studies of the degree of association of Grignard reagents28b at high concen-trations tend to favour halogen- rather than organo-bridges in the associated RMgX species.Such bridging is certainly found28c in the central four-membered MgBr,Mg ring of crystalline [EtMgBr .NEt,], in which the bridging Mg-Br distances (2.57 A) are markedly shorter than those reported (2.79-3.02 A)28d for formally single Mg-Br bonds in MgBr2,2Et,O molecules. Aggregation into (RMgX) units in some cases with n > 2 (e.g. PhMgBr) in Et,O implies that different Grignard reagents may have different associated forms ;28b conflicting or apparently anomalous degrees of association reported for some of these systems may be due to the non-ideality of the solutions at high con-centration. In dilute THF solutions R,Mg and MgX (R = Et or Ph ; X = C1 or Br) react almost instantaneously with absorption of heat ;28e reactants and products are largely monomeric.For the system : R,Mg + MgX,= 2RMgX, the formation constant of the Grignard reagent is smaller and the entropy change very much larger than for the corresponding system in ether solution.28e The ”F n.m.r. spectra measured over a range of temperature distinguish28f unambiguously between the fluoroaryl (RF) species ‘R,MgX’ and ‘(RF),Mg’ ; the ratio 2[RFMgx]/[(RF),Mg] in ether solutions of the Grignard reagents increases as the fluorine atoms in the aromatic nucleus are replaced by chlorine or hydrogen while the rate of fluoroaryl exchange follows the sequence : C,F,MgI < C,F,MgBr < C6FsMgC1 6 C,,H,FMgI < C6H2Cl,FMgBr c p-FC,H,MgI < p-FC,H,MgBr. Exchange of alkyl groups28g between such species as Me,Mg and MeMgC,H is catalysed by MgBr but retarded by good solvating agents like Me,N [CH,] NMe,.Amino-magnesium deriva-tives [(Me,N),Mg] and [RMg(NR’,)] (R = Et or Pr‘; NR’ = NPh, NPr’,, or 2,2,6,6-tetramethylpiperidino) are formed2’ from secondary amines and magnesium dialkyls ; these give complexes (e.g. EtMgNPh2,2THF monomeric in benzene) with Et,O or THF. The ether-free compounds are polymeric unless steric factors intervene ; dimers presumably with three-co-ordinate magnesium result when the groups attached to nitrogen -are relatively bulky, examples being [Pr’Mg NPr’,] and [EtMgN(Ph)CH(Et)Ph], the latter formed from Et,Mg and ben~ylideneaniline.~’ The standard heat of formation of Mg(C,H,), determined from the heat of hydr~lysis,~’ is AH 298 = - 16.0 f 0.8 kcal./mole; although Mg(C,H,) is more stable than Ni(C,H,) and Fe(C,H,), with respect to the elements the high free-energy of formation of ’13 (a) E.C. Ashby Quart. Rev. 1967 21 259; (b) E. C. Ashby and F. Walker J . Organometallic Chem. 1967,7 P17; (c) J. Toney and G. D. Stucky Chem. Comm. 1967 1168; (4 H. Schibilla and M.-T. Le Bihan Actu Cryst. 1967 23 332; (e) M. B. Smith and W. E. Becker Tetrahedron 1967, 23,4215; v) D. F. Evans and M. S. Khan J . Chem. SOC. (A) 1967,1643; (9) H. 0. House R. A. Latham, and G. M. Whitesides J . Org. Chem. 1967,32 2481. ’’ G. E. Coates and D. Ridley J . Chem. SOC. (A) 1967 56. ’O H. S. Hull A. F. Reid and A. G. Turnbull Inorg. Chem. 1967,6,805 The Typical Elements 225 MgC12 results in the metathesis : Mg(CsHs)2 + MC12 + M(C5HJ2 + MgC12 (M = Ni or Fe).The 9Be magnetic resonance31 of a number of compounds containing beryllium bound to electronegative atoms (F 0 N or C1) is insensitive to structural effects presumably because of the largely ionic nature of the systems. The temperature-dependence of the I9F n.m.r. spectra of aqueous solutions of (NH4)2BeF4 indicates3 fluorine exchange between BeF42 - and another Be-F species possibly H,O,BeF;. According to transpiration and effusion measurements on beryllium chloride v a ~ o u r ~ ~ the heats of formation of BeCl,(g) and Be2C14(g) are AHf 298 = -84.3 1 3 and - 196.3 & 1.0 kcal./ mole respectively. Of the molecular species isolated from vaporised magnesium fluoride in noble-gas matrices MgF and MgF have been characterised by their i.r.on the evidence of which MgF is bent (LF-M~-F = 145-160”). The properties and likely ingredients of solutions of alkaline earth metals in their molten halides have been reviewed;34“ the anomalous conductivities of the pure halides near their melting-points attributable to the formation of ordered domains,34b raises doubts about the postulated formation of M22+ species (M = Ca or Sr) in halide melts containing the dissolved metal M. Investigations of the hydrolysis of the beryllium ion in a q u e o ~ s ~ ’ ~ * ~ and dio~ane-water~’~ solutions agree that Be3(0H)33+ is the main product to-gether with Be20H3+ but differ over the contribution of neutral Be(OH),. Analysis of potentiometric measurements in lm-NaC1 suggests3’“ the formation not of Be(OH), but of a more complicated polynuclear species most probably Be,(OH)73 + in nearly neutral solutions.A further hydroxo-complex Be2(OH)22+ was identified3’“ in dioxane-water mixtures. In crystalline Sr(OH),,H,O each Sr2 + ion is surrounded by eight nearest neighbours (six OH- ions and two H 2 0 molecules) at the corners of a bicapped trigonal prism;36 the polyhedra are linked together by triangular faces to give layers between which there are strong hydrogen bonds. Group HI.-Boron. During the year there have appeared new books about boron and its compounds37 and about organoboron-nitrogen and -phosphorus corn pound^.^^ Boranes and carboranes have been the subject of a brief 31 J. C. Kotz R. Schaeffer and A. Clouse Znorg. Chem. 1967,6,620.’* H. C. KO M. A. Greenbaum M. Farber and C. C. Selph J . Phys. Chem. 1967,71,254. ’’ D. E. Mann G. V. Calder K. S. Seshadri D. White and M. J. Linevsky J . Chem. Phys. 1967, 46,1138. 34 (a) D. Richter and H.-H. Emons 2. Chem. 1966 6,407; (b) H.-H. Emons and D. Richter, Z . anotg. Chem. 1967,353,148. ’’ (a) R. E. Mesmer and C. F. Baes jun. Znorg. Chem. 1967,6,1951; (b) F. Berth G. Thomas and J . C . Merlin Bull. SOC. chim. France 1967,2393 ; (c) H. Ohtaki Znorg. Chem. 1967,6,808 ; H. Ohtaki and H. Kato Inorg. Chem. 1967,6 1935. ’’ H. Barnighausen and J. Weidlein Acta Cryst. 1967 22 252. ’’ E. L. Muetterties ‘The Chemistry of Boron and its Compounds,’ Wiley New York 1967. H. Steinberg and R. J. Brotherton ‘Organoboron Chemistry Vol. 2. Boron-Nitrogen and Boron-Phosphorus Compounds,’ Interscience London and New York 1966 226 A.J. Downs G. M . Sheldrick and J . J . Turner and a fuller review,39b in which the term 'boracarbane' has been coined for the recently discovered carbon-rich carboranes like tetracarba-hexaborane. In experimental terms the most significant advances appear to have been in the realm of preparative chemistry as in the synthesis of boranes or carboranes in which the atoms phosphor~s,~~" sulphur or nitrogen40b are incorporated in the polyhedral framework. There have been few new develop-ments in physical techniques though the use of chromatographic methods has been described41 as a means both of separating non-ionic boron com-pounds and of investigating their interactions with donor molecules. In the subsequent account more specific topics will be considered in the following order n-bonding donor-acceptor properties metal-boron compounds, cationic species boron hydrides and carboranes (to be discussed in order of increasing complexity) boron-halogen -nitrogen -oxygen -sulphur and -selenium compounds and finally organoboranes.Of the theoretical aspects of bonding in boron compounds the incidence and extent of x-bonding have attracted most attention. According to bond-energy calculations based on a-charge maps,42 the contribution of x-back-donation in B-X bonds decreases in the order B-F > B-OR > B-NR2 > B-Cl > B-Br > B-I. A less obvious manifestation of this effect is claimed for the successful fractionation4 of loB and "B by the reaction: Donor-"BF,(l) + "BF,(g) + Donor*"BF,(l) + "BF,(g); the equilibrium quotient K = [Donor "BF,]/[Donor* "BF,] > 1 varies with the donor in the order Et2S > Me,S > Me2Se > Bu2S > Et20 > PhOMe > Me20 2 THF > PhOH > Et,N.In view of the usual qualitative notions it is surprising that according to SCMO methods,440 the 7c-energy does not decrease in the series of monomeric trihalides BX, AlX, GaX,, in which BI possesses the lowest n-stabilising energy. Similar calculations imply (i) that in triarylboranes the B-C x-bond orders are (ii) that in non-cyclic Ph-B-X systems the order of x-bonding is B-0 > B-X,44c (iii) that in boroxines the n-charge is less delocalised than in b o r a z i n e ~ ~ ~ ~ a conclusion supported by vibrational analysis of some fluoro- and chloro-bor~xines,~~" and (iv) that there is little conjugation in B-N chains,44f while I 39 (a) M.F. Hawthorne Endeavour 1966,25 146; (b) R. Koster and M. A. Grassberger Angew. 40 (a) J. L. Little J. T. Moran and L. J. Todd J . Amer. Chem. SOC. 1967,89,5495; (b) W. R. Hertler, 41 S. HefmPnek J. PleSek and V. Gregor Coll. Czech. Chem. Comm. 1966,31,1281; S. Hefmhek 42 J.-P. Laurent J.-F. Labarre and J.-P. Bonnet Bull. SOC. chim. France 1967 1148. 43 A. A. Palko and J. S. Drury J . Chem. Phys. 1967,46,2297; 1967,47,2561; G. M. Begun and A. A. Palko J . Chem. Phys. 1967,47,967. 44 (a) D. R. Armstrong and P. G. Perkins J . Chem. SOC. (A) 1967,1218; (b) D. R. Armstrong and P. G. Perkins Theor. Chim. Acta 1967 8 138; (c) D. R. Armstrong and P. G. Perkins J .Chem. Soc. (A) 1967 123; (d) ibid. p. 790; (e) B. Latimer and J. P. Devlin Spectrochirn. Acta 1967,23A 81; v) N. C. Baird and M. A. Whitehead Canud. J . Chem. 1967,45,2059. Chem. Internat. End. 1967,6 218. F. Klanberg and E. L. Muetterties Inorg. Chem. 1967,6 1696. and J. PleSek ibid. p. 1975 The Typical Elements 227 B-N rings which are not characterised by a '4n + 2' n-electron aromaticity rule exhibit a preference for exo- over endo-cyclic n-bonding. The standard enthalpies of formation of Ph,B (C6HI1),B PhBX, and Ph,BX (X = C1 or Br) determined from heats of hydroly~is,~~ indicate that E(B-C) (18-28 kcaljmole) decreases thus PhBX > Ph,BX > Ph,B provided the B-X bond energies are the same as those in BX,. Marked aromatic character is suggested by the chemical and spectroscopic properties of the newly synthe-sised carbon-boron heterocycle (3) isoelectronic with the corresponding benzotropylium cation.46u Likewise the influence of saIt-formation on the ' 'B n.m.r.spectrum of several B-OH borazaro-compounds,46b e.g. (4) is consistent with an aromatic heterocyclic system as are the properties of 7,6-borazarothieno-[3,2-c]-pyridine (5a) and 4,5-borazarothieno-[2,3-c]-pyri-dine (5b) but not of 7,6-borazarothieno-[3,4-c]-pyridine (5c) derivative^.^^' H I For the molxule F,P,BH the unexpectedly short B-P bond (1.84&, relatively high barrier to internal rotation (3240 cal./mole) and the high dissociation enthalpy {24-25 kcal. for the reaction F,P,BH,(g) + PF,(g) + BH,(g) (at 298"~)] testify to a strong B-P bond,47 but provide no clearcut case for pn + d bonding.Evaluation of the interactions between boron-acceptor and various donor-molecules has again been the objective of numerous investigations. Thus the dissociation pressure of the new borane adduct H,B,PHF indicates48a that base strength with respect to BH increases in the order PH < PF < PHF,. The standard enthalpies of formation of X,B,PY complexes (X Y = Br or I), determined from measured heats of hydrolysis,48b lead to donor-acceptor " A. Finch P. J- Gardner E. J. Pearn and G. B. Watts Trans. Faraday SOC. 1967,63,1880. '' (a) A. J. Leusink W. Drenth J. G. Noltes and G. J. M. van der Kerk Tetrahedron Eetters, 1967 1263; (b) M. J. S. Dewar and R. Jones J . Amer. Chem. SOC. 1967 89 2408; (c) S. Gronowitz and J.Namtvedt Acra Chem. Scad. 1967,21,2151. 47 R. L. Kuczkowski and D. R. Lide jun. J . Chem. Phys. 1967,46,357. (a) R. W. Rudolph and R. W. Parry J . Amer. Chem. SOC. 1967 89 1621; (b) A. Finch P. J. Gardner and K. K. Sen Gupta Inorg. Chem. 1967 6 386; (c) R. S. Satchell and D. P. N. Satchell, J . Chem. SOC. (B) 1967 36; A. Mohammad and D. P. N. Satchell ibid. pp. 403 726 228 A. J . Downs G. M. Sheldrick and J . J . Turner bond energies which are believed to reflect the influence of both donor-acceptor affinity and steric hindrance. For the 1 1 adducts formed initially by BF, AlBr, GaCl, or GaBr with substituted anilines in ether s01ution,~~~ the formation constants K at 25" are given by pK = ApK, + B where K , is the dissociation constant of the corresponding anilinium ion and A and B are constants for a given acceptor ortho-substituents tend to hinder adduct-formation.At the same time some pitfalls which beset arguments about donor and acceptor strengths have also been pointed out. For example it is con-~ l u d e d ~ ~ as the result of SCMO calculations on MX molecules (M = B Al, or Ga ; X = halogen) that neither the electron density on the central atom nor the M-X bond order is a meaningful index of acceptor strength. Further a 'H n.m.r. study of Et20-BX3 systems (X = F C1 or Br) whilst ruling out the existence of BX,,2Et20 species also suggests49a that any correlation between Lewis acidities and the separation of resonances due to bulk and complexed ligand is purely coincidental. The adducts SiH,PH 2,BC13, SiH PH 2,BH , SiH PH ',B2 H Br and SiH PH2,BH ZBr formed from SiH,PH and the appropriate boron accept~r,~'' decompose at - 23- -45"c, but differences in thermal stability between these and analogous PH adducts probably result from different decomposition routes rather than differences in donor strength.There is some confusion about the interpretation of the "B n.m.r. spectra of amine-boranes with the composition B,H,,NR ; one sugge~tion~~" is that the B2H6 molecule which is potentially a x-acceptor, remains intact but the failure of "B,H6 to exchange with Me,N,BH, with other e~idence,'~' supports the singly hydrogen-bridged structure R3N BH,-H-BH proposed. According to dipole moment measurements, the internal co-ordination believed to occur in 3-aminopropylboranes (6) is destabilised' when the hydrogen atoms on the nitrogen are replaced by alkyl groups or when alkoxy-groups are attached to the boron.Recent developments in the chemistry of borane adducts include the isolation of the crystalline species P406,3BH3 as well as P,06,2BH3 in solution equilibria are rapidly established between all the members of the series P406,XBHS (x = 0-4) in which the P406 cage probably remains intact."" The stoicheiometry and probable site of co-ordination of some BH adducts of simple and polycyclic ligands containing more than one potential donor are reported,"' while the species Et,N,BH,X (X = H C1 Br I or Ph) have been characteri~ed.~~' The range of metal-boron compounds has undergone both expansion and diversification. By oxidative addition of Y *BX to compounds of transition metals in low oxidation states e.g., '' (a) R.E. Schuster A. Fratiello and T. P. Onak Chem. Comm. 1967 1038; (b) J. E. Drake and 50 (a) J. F. Eastham J . Amer. Chem. Soc. 1967,89 2237; (b) S. G. Shore and C. L. Hall J . Amer. 51 N. V. Mostovoi V. A. Dorokhov and B. M. Mikhailov Bull. Acad. Sci. U.S.S.R. 1966 70. '' (a) J. G. Riess and J. R. Van Wazer J . Amer. Chem. Soc. 1967,89,851; (b) B. L. Laube R. D. Bertrand G. A. Casedy R. D. Compton and J. G. Verkade Znorg. Chem. 1967,6 173; (c) J. N. G. Faulks N. N. Greenwood and J. H. Morris J . Znorg. Nuclear Chem. 1967,29 329. J. Simpson Inorg. Chem. 1967,6 1984. Chem. SOC. 1967,89,3947 The Typical Elements 229 Ph RB Ph (7) Y Y R Y Y [(n-C,H,),Ti] + Y,BX + 2(n-C5H,),TiX(BY2), new o-bonded metal-boron species have been synthesised typical of these are (n-C,H,),TiX(BY,) diphos,CoX(BY,) and (Ph,P),PtX(BY,) (X = C1 or Br; Y = C1 Br or Ph; diphos = Ph,P-[CH,],*PPh,).Metal carbonyl complexes of the type X,B*M(CO),(n-C,H,) (X = Ph or C1 and M = Mo or W) from the reaction of X2BCl with Na[M(CO),(n-C,H,)]; the dichloride species form 1 1 adducts with Et,N. Cobalt complexes trans -diphos,Co(BR,) [diphos = Ph2P*[CH2] *PPh or o-C,H,(PM~,)~ BR, = BPh2 or 9-borafluorenyl] prepared from diphos,CoH and R,BC1 lead to Fe-BR, Mn-BR, Ni-BR and Au-BR derivatives by ligand-exchange reactions.53c By contrast the lithium derivative of 2,5-diphenyl-3,4-dimethyl-l,3,4-triazadiborolan (7) ‘TADBLi,’ reacts with FeCl to give the monomeric diamagnetic compound (TADB),Fe for which a sandwich struc-ture is suggested.’ 3d Borazines are apparently capable of forming n-complexes with transition metals ; thus hexamethylborazine displaces the nitrile ligands from (MeCN),Cr(CO) to form monomeric (Me,N,B,Me,)Cr(CO), analo-gous to (MegCg)Cr(C0)3.54a Interaction in the system hexamethylborazine-Mo(CO), with the formation of Mo(C0),,3Me,N3B,Me, and Me,N,B,Me,, 2Mo(CO) is also implied54b by thermal analysis.Simple molecular-orbital calculations confirm that metal n-complexes of borazine are electronically feasible,54‘ though the interaction energies are less than those of corresponding ’’ (a) G. Schmid W. Petz W. Arloth and H. Noth Angew. Chem. Internat. Edn. 1967 6 696; (b) G. Schmid and H. Noth J .Organometallic Chem. 1967,7,129; (c) G. Schmid and H. Noth Chem. Ber. 1967,100 2899; (d) H. Noth and W. Regnet Z . anorg. Chem. 1967,352 1. s4 (a) R. Prinz and H. Werner Angew. Chem. Internat. Edn. 1967 6 91 ; (b) E. M. Fedneva and I. V. Kryukova Doklady Chem. 1966 170 951; (c) D. A. Brown and C. G. McCormack Chem. Comm. 1967,383 230 A. J . Downs G. M. Sheldrick and J . J . Turner arene systems. Ligands of a formally more conventional but nevertheless novel type are the poly( 1-pyrazoly1)borate anions,55 which can behave as either bidentate (8a) or tridentate (8b) ligands. The ligand (8b) leads for example to numerous stable transition-metal complexes e.g. (8c) the chemistry of which is reminiscent of that of z-cyclopentadienyl derivatives. The range of complexes in which metal atoms are incorporated into polyhedral frameworks has also been enlarged.Thus the C2B,H,,- ion with MC12 (M = Fe Co or Ni) to give the 1,2-dicarbollyl complexes [M"(C2B9H ,),]" which are oxidised to [M1''(C,B9H1,),]- (M = Fe Co, Ni) and M'V(C,B,H,,)2 (M = Ni). The affinity of these complexes to z-cyclo-pentadienyl derivatives is well illustrated by the structure of the [Co(C2B,H ,),I - which consists of two staggered icosahedra sharing a common apex the cobalt atom. However the structure of the [Cu(C2B,H ,),I2 - ion in crystalline (Et4N),[Cu(C2B9H1 1 ) 2 ] involves distortion of this highly symmetrical arrangement by a shkaring movement of the carborane moieties (9).56c The relatively short C-C distance (1.53 A) in b the open faces of these units suggests that the x-electrons of the carbon atoms contribute little to the metal-cage bonding.Transition-metal complexes of the eleven-atom icosahedral fragments B,,HloCH3- and B,,H,,CNH,R2-(R = H Et or Pr),57a9b and BloH,,S2- (ref. 40b) have been synthesised by methods similar to those described for the complexes of the isoelectronic C2B9H1 ion; typical species are [M(B,,H,,CNH,),]"- and [M(B,,H,,CH)2]"- (M = Cr Mn Fe Co or Ni). Reactions of the amino-group of the complexed Bl,H,,CNH32- ion give to other C-substituted complexes e.g. [Ni(B,,H,,C~ OH),],-. From the reaction of M(CO) (M = Cr Mo or W) with the B,H,- ion the anions [(OC),MB,H,]-5 5 J. P. Jesson S. Trofimenko and D. R. Eaton J . Amer. Chem. SOC. 1967,89,3148; S. Trofimenko, ibid. pp. 3170,3904,6288.56 (a) L. F. Warren jun. and M. F. Hawthorne J . Amer. Chem. SOC. 1967,89,470; (b) A. Zalkin, T. E. Hopkins and D. H. Templeton Inorg. Chem. 1967 6 1911; (c) R. M. Wing J . Amer. Chem. Soc. 1967,89,5599. " (a) D. E. Hyatt J. L. Little J. T. Moran F. R. Scholer and L. J. Todd J . Amer. Chem. SOC., 1967,89,3342; (b) W. H. Knoth J . Amer. Chem. SOC. 1967,89,3342 The Typical Elements 23 1 are formed,58a while the reaction of (Ph,P),CuCl with CsB,H gives 58b the complex (Ph,P),CuB3H8 which according to its conductivity in MeCN, possibly dissociates as [(Ph3P),Cu],B,H82+2B,H -. Hydrogen bridging between the metal and B,H unit confirmed in crystalline [Me,N] [(OC)4CrB3H,] (lo) involves a B,H2 and not the BH unit suggested for (Ph3P)2C~B3H8.58u Thc formation of other hydrogen-bridged transition-metal complexes of the type (Ph,P),M,L (M = Cu Ag or Au; and L = B9H14- B,H,,S- B10H13- and B 1H14-) has also been mentioned.58a H H H \ H /" Ma The most significant development in the chemistry of boronium cations has been the partial resolution of a salt of the [HB(Cl)(NM3,) (4-picoline)I' optically active ion prepared from Me,N,BHT and 4 - p i ~ o l i n e .~ ~ " Me,N,BBr, reacts with 4-ethylpryridine pyridine and either 3,5-dimethyl- or 3-chloro-pyridine to produce water-soluble bromides formulated respectively as [py4B] Br, [py,BBr] Br, and [py2BBr,]Br on the basis of conductivity measurements;59b salts of the tri- di- and uni-valent cations with the PF6-and AsF - anions have also been prepared. The formation and properties of the cations depend upon the basicity and steric properties of the amine.58 (a) F. Klanberg and L. J. Guggenberger Chem. Comm. 1967 1293; (6) S. J. Lippard and D. Ucko Chem. Comm. 1967,983. 59 (a) G. E. Ryschkewitsch and J. M. Garrett J . Amer. Chem. SOC. 1967 89 4240; (6) C. W. Makosky G. L. Galloway and G. E. Ryschkewitsch Inorg. Chem. 1967,6 1972; (c) J. E. Douglass, G. R. Roehrig and 0. Ma J . Organometallic Chem. 1967,8,421; (d) G. E. Ryschkewitsch J . Amer. Chem. SOC. 1967,89 3145; (e) 0. T. Beachley jun. Znorg. Chem. 1967,6 870; v) R. J. Rowatt and N. E. Miller J . h e r . Chem. Soc. 1967,89 5509. H 232 A. J . Downs G. M . Sheldrick and J . J . Turner Steric effects are also evident in the reaction of iodine with amine-boranes, RBH,,py and R,BH,py when R is a bulky substituent (e.g.c y c l o h e ~ y l ) ~ ~ ~ boronium cations e.g. [R,B py2]+ being formed only in the absence of an excess of pyridine. The formation of salts of the [H,B py,] + ion by the reaction of Me,N,BH with iodine in pyridine is believed59d to proceed initially by hydride abstraction from the amine-borane. According to synthetic and trapping techniques,59e the formation of (H2B *NHMe) by the pyrolysis of H,B,NH,Me depends on the initial formation of first [H2B(NH2Me),] +BH4-and then [H,MeN.BH,*NHMe*BH,.NH,Me]+BH,- ; in such dehydro-genation reactions the intermediates are likely to have an important influence on the degree of association of the product. Other new borane cations include the first examples of bis- and tris-borane cations,"f viz.the sulphur-bridged species [Me N*BH,-S( Me)-BH ,"Me,]+ and [Me N-BH ,-S( Me)] BH2+ made from Me,N,BH,SMe. The BH molecule has been identified spectroscopically as one of the products of the flash photolysis of H,B*CO ;60 in its ground state the H-B-H angle is 131". Another transient species the radical anion *BH,- is the main paramagnetic ingredient of y-irradiated KBH at 7 7 " ~ on the basis of e.s.r. studies.61 The isoelectronic nature of H,B*CO and C02 is strikingly displayed in the successful synthesis6," of salts of the boranocarbonate ion [H,B.C0,I2-. The boranobicarbonate ion [H,B*C(OH)O] - is formed by addition of HCl toanaqueous boranocarbonate solution. The hypothetical H,[H,B- CO,], with a pK2 value62a similar to that of H2C03 may be the precursor62b to the formation of (HO),BCH,*OH in the hydrolysis of H,B.CO.The [H,P(BH,),] - ion analogous to the hypophosphite ion has been identified by chemical and physical methods in the amine addition compounds62c of H,B,PH and in NaH,P(BH,), formed from NaBH and PH41 at -78"c in monoglyme.62d Phosphorane boranes of the type Ph,f'CH(R),BH undergo skeletal rearrangement followed by redistribution of the groups attached to boron :63 + - 131" -k - 190" e.g. Ph,P-CH,-BH -Ph,P.BH2CH -2/3Ph,P.BH3 + 1 /3Ph,P + 1/3 BMe,. BH,CI and BHCl are formed64a by the reaction of hydrogen chloride with solutions of diborane in THF; the reactivity of these chloroboranes with respect to olefin-addition is related only indirectly to the relative Some interesting structural details have come to light concerning a number 6o G.Herzberg and J. W. C. Johns Proc. Roy. SOC. 1967 A 298 142. 61 M. C. R. Symons and H. W. Wardale Chem. Comm. 1967,758. 62 (a) L. J. Malone and R. W. Parry Inorg. Chem. 1967,6,817; (b) L. J. Malone and M. R. Manley, Inorg. Chem. 1967,6,2260; (c) J. W. Gilje K. W. Morse and R. W. Parry Inorg. Chem. 1967,6,1761; (d) R. E. Hester and E. Mayer Spectrochim. Acta 1967 23A 2218. 63 R. Koster and B. Rickborn J . Amer. Chem. Soc. 1967,89,2782. 64 (a) G. Zweifel J . Organometallic Chem. 1967,9,215; (b) D. J. Pasto and P. Balasubramaniyan, J . Amer. Chem. SOC. 1967,89,295 The Typical Elements 233 of metal borohydrides. Thus a new electron diffraction of Be(BH4), vapour indicates not the symmetrical bridged structure previously favoured, but a triangular arrangement of the heavy atoms with CZ0 symmetry (1 1) ; the terminal Be-H distances of 1.61 $ 0.02 A imply a fractional bond-order.X-Ray crystallographic studies indicate (a) that the copper atom in (Ph,P),CuBH has a quasi-tetrahedral environment being linked to the BH4 group via two hydrogen-bridges,66" and (b) that in crystalline Zr(BH,) at -160"~ the zirconium is presumably linked to each BH group by three hydrogen-bridges.66b According to recent studies the action of heat on liquid Al(BH4) produces either a reversible or an irreversible change in the 'H n.m.r. spectrum and it has been suggested that some structural modification takes place.67a Displacement reactions have been to deduce the following relative affinities of donor molecules with respect to 1 1 complex-formation with A1(BH4), NMe - PMe > AsMe and Me,O > Me2S.The reaction of A1(BH4) with appears to give ultimately a product which approximates in composition to Al(BH4),,6NH,. In the reaction of BCl with NaAlH to produce B2H6 the intermediate A1C1,BH4 and its etherate AlCl,BH,,OEt have been isolated.67d Recent conclusions about the 'triple hydrides' formed in ether solutions of LiAlH and B2H6 have been confirmed,67e but conductivity measurements point to an equi-librium : MBH4 + Al(BH,+) + M[Al(BH,),], in which formation of M[Al(BH,),] is favoured by bulky M + ions e.g. [(C8H 7)3NC3H7] + Similarly Be(BH4)2 adds to MBH to give67e M[Be(BH,),] and M[Be2(BH4),] ; Al(BH4) and Be(BH4) appear to be stronger Lewis-acids than BH with respect to the BH,- ion.Some of the physical and chemical properties recently reported67f for Mg(BH,), prepared from MgH and B2H6 in Et,O conflict markedly with previous information about this compound. Mass-spectrometric studies of the pyrolysis of B2H6 lead68 to appearance potentials of B+ BH' and BH2+ from B2H6 or BH, and of BH3+ and B2H5+ from B2H6 and to the ionisation potential of BH,; subsequent calculations of the energy terms in the B,H,-BH system give inter aha, D(BH,-BH,) = 59 kcal./mole for gaseous B&. New or modified methods of preparing B& which have been developed include the catalysed high-6 5 A. Almenningen G. Gundersen and A. Haaland Chem. Comm. 1967 557. 66 (a) S. J. Lippard and K. M. Melmed Inorg. Chem.1967 6. 2223; (b) P. H. Bird and M. R. Churchill Chem. Comm. 1967,403. " (a) P. C. Maybury and J. E. Ahnell Inorg. Chem. 1967,6 1286; (b) P. H. Bird and M. G. H. Wallbridge J . Chem. Soc. (A) 1967,664; (c) J.-C. Fauroux and S. J. Teichner Bull. SOC. chim. France, 1967 4052; (d) T. Hanslik J. PleSek and S. H e a n e k Coll. Czech. Chem. Comm. 1966 31 4215; (e) H. Nijth and M. Ehemann Chem. Comm. 1967 685; v) J. PleHek and S. Hefmhnek Coll. Czech. Chem Comm. 1966,31,3845. '* J. H. Wilson and H. A. McGee jun. J . Chem. Phys. 1967,46 1444 234 A. J. Downs G. M. Sheldrick and J. J . Turner pressure hydrogenation of RBC12 (R = alk~l)~'" and the high-pressure reduction of BCl or BBr with hydrogen in the presence of a metal.69b Of the reactions of B2H6 with BX (X = F C1 Br) that with BCl has been studied in some the proportions of BH,Cl BHCl, and B,H5C1 formed depend on the composition of the initial reaction mixture.The new substituted dibmane B,H,(PF,) results7' from the reaction of B,H,,OMe with PF, at - 15"c. Two distinct stages have been noted7' in the vapour-phase reaction of B4H with acetylene under mild conditions (25-5O"c) open-cage carboranes containing hydrogen bridges are formed ; at 1oO"c a flash reaction takes place to give closed-cage carboranes containing 3-8 boron atoms. Certain features of this reaction seem to be common to other vapour-phase reactions between boranes and alkynes ;71 evidently the nature of the open-cage carboranes formed in the low-energy reactions depends on the borane starting material, whereas the closed-cage carboranes formed in the high-energy reactions (electric-discharge or flash reactions) are distributed largely according to their relative thermodynamic stabilities.2,4-Dimethylenetetraborane which con-sists of a tetraborane skeleton bridged diagonally by a -CH2 - CH,- unit is formed from B,H1 and ethylene according to the scheme:72 the absence of hydrogen transfer is confirmed by reference to the deuteriated product D4C2B4H8. Salts of the B5H8- ion have been prepared by the reaction of ~rganolithium~~" or alkali-metal h y d r i d e ~ ~ ~ ~ ' with B5Hg to which the anion is presumably related by loss of a proton from one of the basal boron atoms; the magnetic equivalence of the basal boron atoms in the B,H8- ion at room temperature is probably due to facile hydrogen exchange, though there are some discrepancies in the reported "B n.m.r.~ p e c t r a . ' ~ ~ . ~ Some reactions of the B5H8- ion have been r e p ~ r t e d ~ ~ " * ~ ~ ~ (see Scheme l), MBH +- B6HI0 4 p-MeJSiB,H, SCHEME 1 B 1 0 H 1 4 69 (a) A. I. Gorbunov and G. S. Solov'eva Russ. J . Znorg. Chem. 1967,12,1; (b) J. Cueilleron and J.-L. Reymonet Bull. SOC. chim. France 1967 1367; (c) J. Cueilleron and J. Bouix Bull. SOC. chim. France 1967,2945. 70 W. R. Deever and D. M. Ritter J . Amer. Chem. SOC. 1967,89,5073. 7 1 R. N. Grimes and C. L. Bramlett J . Amer. Chem. SOC. 1967,89,2557. 'I' R. E. Williams and F. J. Gerhart J . Organometallic Chem. 1967 10 168. 'I3 (a) D. F. Gaines and T. V. Iorns J . Amer. Chem. SOC. 1967,89,3375; (b) T.Onak G. B. Dunks, I. W. Searcy and J. Spielman Znorg. Chem. 1967,6 1465; (c) R. A. Geanangel and S. G. Shore J . Amer. Chem. SOC. 1967,89,6771; (d) D. F. Gaines and T. V. Iorns J . Amer. Chem. SOC. 1967,89,4249 The Typical Elements 235 Studies of internal hydrogen exchange in B,H9 suggest that at least two mechanisms are possible according to the strength of the Lewis-base catalyst used;73a likewise the rate of apex-to-base rearrangement of a number of alkylated pentaboranes depends on the number of alkyl substituents and on the properties of the base.73b The reaction of LiB,H with Me,SiCl in ether solution at low temperature gives a compound believed to be p-Me3SiB5H, (12) the first example of an electron-deficient system incorporating boron and Isomerisation of p-Me,SiB,H to 2-Me3SiB5H occurs at room temperature in the presence of Me20.Pyrolysis of C,3-dimethyl-1,2-dicarba-clovopentaborane(5) produces a variety of thermally more stable polymethy-lated derivatives of 1,2-dicarbaclovopentaborane(5) but no rearrangement of the carborane cage ;74 formation of the supposedly more stable 1,5-carboranes seems to be inhibited by the methyl substituents. Air oxidation of the B9H92-ion under carefully prescribed conditions of the solution leads to a series of polyhedral ions including the known B6H62- and the previously unknown B7H7'- and B,HS2- ions.75 An intermediate in this oxidation is a para-magnetic species identified as B,H *- for which there is convincing evidence of electron delocalisation in the polyhedral cage.In its tetra-amminezinc salt the BsHS2- ion has a slightly distorted dodecahedra1 structure7' similar to that of BsC18. The B6C2 polyhedron in crystalline B6H6C2Me2 at -50" (13) is likewise structurally related to B8C18 and not to the Archimedean antiprism suggested by 'B n.m.r. data.76 The first boron-permethyl clovocarborane (HC),B,Me, derived from 2,4-dicarbaclovoheptaborane(7) has been pre-pared,77 together with mono- di- tri- and tetra-methyl derivatives by the co-pyrolysis of 2,3-dicarbahexaborane(8) and Me,B at 300"c. X-Ray analysis confirms78 that the B C unit in crystalline B7C2H,,Me2 is an icosahedral fragment with two adjacent hydrogen-bridges and two CHMe groups in the open face (14). .7 a2 H M? H H " R. N. Grimes J . Organometallic Chem. 1967,8,45.'' F. Klanberg D. R. Eaton L. J. Guggenberger and E. L. Muetterties Inorg. Chem. 1967,6,1271. 76 H. V. Hart and W. N. Lipscomb J . Amer. Chem. SOC. 1967,89,4220. " H. V. Seklemian and R. E. Williams Inorg. Nuclem Chem. Letters 1967,3,289. '' D. Voet and W. N. Lipscomb Inorg. Chem. 1967,6 113 236 A. J . Downs G. M . Sheldrick and J . J . Turner Polyhedral thia- and aza-boranes have been prepared as shown in Scheme 2.40b These compounds are probably of three structural types viz. (i) 12-atom Dehydration Lewis base acid B9Hl,S.L (NH4)2Sx B9;12s - of conjugate B9H11S i of c s + salt I i Acidification BIOH 11 s - -B 1 OH 1 2 s Me,N-N:S ,' \ Strong B l 0 H l 4 ~ < y B ,H 1 oS2 - L P h B PhBCl ,H ,S Me,N -NB9Hl -SCHEME 2 icosahedral cages (e.g. PhB ,H,,S) (ii) 11-atom units analogous to C2B9Hll2-(e.g.B,0HloS2-) C2B9HL2- (e.g. BlOHl1S-) and CZB9H13 (e.g. BloH12S), and (iii) 10-atom units analogous to B10H142- (e.g. BgH12S-) and B10H13-(e.g. BgHl lS). The introduction of phosphorus into the icosahedral framework has been achieved4'" in the compounds 1,2-(HC)P*Bl0H,, 1,7-(HC)* B,,HloP and B ,H ,PPh prepared thus : Na3B,,HloCH,2THF % 1 ,2-(HC)P*B,,H =1,7-(HC)* B ,H ,P 2-PhPCI B11H13 ~- -+%I 1H1 1PPh. The new phosphaborane and carbaphosphaborane resemble the corres-ponding mono- and di-carbaclovododecaboranes for example in the thermal isomerisation of 1,2-(HC)PB,,H ' metallation of 1,7-(HC) Bl,H ,,P with BuLi and electrophilic bromination of 1,2-(HC)P* BloH,,. Another important synthetic advance has been the preparation of the l-BgHgCH- and B,,H,,CH- ions by somewhat involved methods,57by 79a e.g.as in Scheme 3. These ions are the missing links in the BlOHlo2--B,C2Hlo and B12H122-B,oCZHlZ series respectively; the species I gIs3a:;o Cs(l-B,H,CH) + CsB,,H ,CH SCHEME 3 79 (a) W. H. Knoth J . Amer. Chem SOC. 1967,89,1274; (b) D. E. Hyatt F. R. Scholer L. J. Todd, and J. L. Warner Znorg. Chem. 1967,6 2229; (c) C. J. Fritchie jun. Znorg. Chem. 1967,6 1199 The Typical Elements 237 B,H ,CNH3 B,H ,CNMe3 and BloHl0CH- represent other new car-boranes formed as intermediates in the various syntheses. The BlOH ,CH -ion has been prepared79b directly by the deamination of B10H12CNR3 (R = alkyl) with either NaH or sodium metal in THF; this ion appears to be inter-mediate in the formation of the BloHl0CH3- ion the metal complexes of together with those of the B,oH,oCNR32- ion have been men-tioned elsewhere.Iodine oxidation of the B,,H,,CH- ion produces 79b the B,,Hl0CH- ion. The reactivity of halogens with respect to BloHl2CH- and BloHI2CNR3 decreases in the order Cl > Br > I and reference to a specifi-cally labelled bromo-derivative prepared from 2-B ,H ,Br that B-4,6 are the initial sites of attack in the carborane cage (15). The open-face icosahedral structure of the B 1H13,- ion isoelectronic with B,,H,,CH-, has been confirmed79' in crystalline CsMe,NB H I 3. N% ,I 8 I I 4 6 (15) High yields of salts of the B,oH,02- anion have been achieved"" by the pyrolysis of Et,NBH or Et,NB3Hs; the nature of the cation has a major influence on the course of the pyrolysis not only of the salts M'BH and M1B3H8,80a but also of polyhedral hydroboratesSob M'BlOHl 3 M',Bl0Hl4 and M'BloH,,.In the formation of the Bl0HlO2- ion from BloH1,L2 com-pounds and in the ligand exchange reactions of the latter a highly reactive intermediate B,,H ,L common to both processes is suggested by kinetic data.8oc Conversely the B ,H 0 2 - cage in (NH,)2BloH,o is openedSod by the action of HCl in Et,S to re-establish the decaborane skeleton of B1,H,,(SEt,),. Carbonyl derivatives of the BloHlo2- and B,,H,,2- ions have been prepared,81" for example by the reaction of hydrated H,B,,H12 with CO which gives 1,7- and l,12-B12Hlo(CO)2 and B12H l(CO)-. These react reversibly with water to form the corresponding carboxylic acids and with alcohols or amines to form esters or amides respectively; accordingly, *' (a) J.M. Makhlouf W. V. Hough and G. T. Hefferan Znorg. Chem. 1967 6 1196; (b) A. R. Siedle J. Grant and M. D. Treblow Inorg. Chem. 1967,6 1602; ( c ) M. F. Hawthorne R. L. Pilling, and R. N. Grimes J . Amer. Chem. SOC. 1967,89 1067; M. F. Hawthorne R. L. Pilling and R. C. Vasavada ibid. 1967,89 1075; (d) M. D. Marshall R. M. Hunt G. T. Hefferan R. M. Adams and J. M. Makhlouf J . Amer. Chem. SOC. 1967,89 3361 238 A. J . Downs G. M . Sheldrick and J . J . Turner they are important synthetic intermediates for the attachment of a wide range of substituents to the carborane nucleus.81bve Developments in decaborane chemistry include the revised identification of the low-melting isomer of B10H131 as the l-iodo-derivative,82a and the synthesis of 5-B,,H13X (X = F, C1 Br or I) by the reaction82b of BloH12(SR2)2 with HX.In glyme solutions the electrolytic reduction of BioH14 proceeds in two steps interpreted82c as (i) the formation of B10H14*- which leads to BIoH13- and BIOHIS- and (ii) the reduction of B ,H - giving B ,,H 3 - ; the latter disproportionates into B,,3H142- and B10H122- which regenerate B1oH13- by reaction with bulk A physically plausible extension of the cuboctahedral mechanism of isomerisationS3" accounts convincingly for the distribution of isomers formed during the rearrangement of 9-bromo- 1,2-dicarbaclovododecaborane( 12) at 395-425"~. Other s t ~ d i e s ~ ~ ~ ~ ~ confirm that thermal rearrangement of the halogen atoms accompanies the skeletal isomerisation of mono- and di-halo-o-carboranes and suggest that the two processes proceed through a common intermediate.In accordance with an earlier prediction the isomerisation of m- into o-carboranes takes place83d via dianions of the type B10H14* [ m-RC B 1 OH 10 CR'12 - . The dicarbaundecaboranes o-RR'C2B,H and rn-RC B,H CR' formed from the corresponding 0- and rn-dicarbadodecaboranes are presumed to undergo some skeletal rearrangement when subjected to oxidation by chromic acid.83e Cleavage of the C2B, icosahedron in derivatives of 1,2-(HC)2Bl,H10 to give dicarbaundecaboranes has been shown to occur84" when halomethyl-carboranes such as 1,2-(CICH2),C2B1,H1, react with NH or Et2NH ; zwitterionic products e.g. (16) are reported.A similar reaction occurs when cyanocarboranes like 1,2-PhC(NC*C)B,,Hl, are treated with alcohols.84b (16) (a) W. H. Knoth J. C. Sauer J. H. Baltbis H. C. Miller and E. L. Muetterties J . Amer. Chem. SOC. 1967,89 4842; (b) W. H. Knoth J . Amer. Chem. SOC. 1967,89 4850; (c) W. H. Knoth N. E. Miller and W. R. Hertler Inorg. Chem. 1967,6 1977. 82 (a) A. Sequeira and W. C. Hamilton Znorg. Chem. 1967 6 1281; M. G. H. Wallbridge, J. Williams and R. L. Williams J . Chem. SOC. (A) 1967 132; (b) J. PleSek B. Stibr and S. HeimAnek, Coll. Czech. Chem. Comm. 1966,31 4744; (c) E. B. Rupp D. E. Smith and D. F. Shriver J . Amer. Chem. SOC. 1967,89 5562 5568. 83 (a) H. D. Kaesz R. B a s H. A. Beall and W. N. Lipscomb J . Amer. Chem. Soc. 1967,89,4218; (b) L. I.Zakharkin and V. N. Kalinin J . Gen. Chem. (U.S.S.R.) 1966 36 376; (c) L. I. Zakharkin and V. N. Kalinin ibid. 1967 37 266; (d) L. I. Zakharkin V. N. Kalinin and L. S. Podvisotskaya, Bull. Acad. Sci. U.S.S.R. 1966 1444; (e) L. I. Zakharkin V. N. Kalinin and L. S. Podvisotskaya, ibid. p. 1810. 84 (a) L. I. Zakharkin and A. V. Grebennikov Bull. Acud. Sci. U.S.S.R. 1966 1952; (b) L. I. Zakharkin and A. I. L'vov J . Gen. Chem. (U.S.S.R.) 1966,36 777 The Typical Elements 239 HMe MeN, ,NMe 8 R J X (171 The attachment of two appropriately sited substituents to the carborane nucleus gives rise to optically active isomers now reporteds5 for both 12- and 1 1-atom carboranes e.g. 1-phenyl-3-p-tolyl-1,2-dicarbaclovododecaborane( 12). By a suitable choice of medium isotopic exchange of the hydrogen atoms in 0- and m-carboranes can be induceds6 at either the carbon or the boron atoms.Dipole moment measurementss7 on bromo-o- and -m-carboranes con-firm that in the polar icosahedra of O - ( H C ) ~ B ~ ~ H ~ and m-HC*B,,H,,*CH the carbon and adjacent boron atoms constitute the positive pole. That electrophilic bromination of 1,7-HC B,,H, CH occurs initially at B-9,10, the two sites most remote from the carbon atoms is verifieds8" by crystallo-graphic analysis of the dibromo-derivative. The dimensions of the Bloc2 icosahedra in the molecules m-HC*B,,H,Br *CH and m-HC-B,,Cl,,*CH are very similar.88a* The weak donor-character of the n-electron system of the 1,2-(HC)2B,,H, cage is suggested by the physical properties of (i) the 1-methyl-2-tropenyliumyl derivatives9" in which the cage displays a strong - I but little if any + T donation to the tropenyl ring and (ii) some nickel(I0 and cobalt(l0 chelates of 1,2-bis(mercapto)-o-carborane,89b the electronic spectra of which imply no metal-ligand n-interaction.By contrast the proper-ties of 3-phenyl derivatives of o-carborane e.g. 3-(H0& * C6H,)BloH9 * C2H2, that the 3-substituted 1,2-carboranyl cage exhibits a weaker - Z effect than either the 1,2-carboranyl or 1,7-carboranyl systems. Among the derivatives of dicarbaclovododecaboranes newly synthesised are symmetrical and unsymmetrical C-mercury compounds of both 0- and m-carboranes ;" these are remarkable inter alia for their resistance to ligand-exchange which makes it possible to isolate stable compounds of the type RHgR' e.g.ferro-cenyl - Hg-o-C,(Ph) B,,Hlo. The controlled potential electrolysis of the B12H122- ion in MeCN apparently parallels that of Bl0HlO2 - involving a one-electron oxidation followed by a dimerisation reaction which leaves the BI2 cage intact;91 salts L. I. Zakharkin E. I. Kukulina and L. S. Podvisotskaya Bull. Acad. Sci. U.S.S.R. 1966 1808. 86 V. N. Setkina I. G. Malakhova V. I. Stanko A. I. Klimova and L. I. Zakharkin Bull. Acad. Sci. U.S.S.R. 1966 1627. R. Maruca H. Schroeder and A. W. Laubengayer Znorg. Chem. 1967,6,572. (a) H. Beall and W. N. Lipscomb Znorg. Chem. 1967,6,874; (b) J. A. Potenza and W. N. Lips-comb Proc. Nut. Acad. Sci. U.S.A. 1966,56 1917. 89 (a) K. M. Harmon A. B. Harmon and B. C. Thompson J . Amer.Chem. SOC. 1967,89 5309; (b) H. D. Smith jun. M. A. Robinson and S. Papetti Inorg. Chem. 1967,6,1014; (c) L. I. Zakharkin, V. N. Kalinin and I. P. Shepilov Bull. Acad. Sci. U.S.S.R. 1966 1241. L. I. Zakharkin and L. S. Podvisotskaya J. Organometallic Chem. 1967,7,385; L. I. Zakharkin, V. I. Bregadze and 0. Yu. Okhlobystin J . Gen. Chem. (U.S.S.R.) 1966,36,776. 91 R. J. Wiersema and R. L. Middaugh J . Amer. Chem SOC. 1967,89,5078 240 A. J. Downs G. M . Sheldrick and J. J. Turner of the dimeric product B24H2-3 - have been isolated. Thermal decomposition of B,H,,,SMe has been shown9 to afford a new synthesis of BI8H2, the formation of which has been interpreted mechanistically. Gaseous BF has been obtained by the low-pressure reaction of BF with boron at 2000"; the compound reacts with B,F, CO and PF to give B,F5, (BF2),BC0 and (BF,),BPF, re~pectively.~~ Alkenes and cycloalkenes with chlorine or bromine atoms in the vinyl or ally1 positions can be completely de-halogenated by organo-boron hydrides with the formation of organo-boron halides.94 There have been three separate reports based on the analysis of reaction products supporting the predominantly cis-addition of B,Cl to alkenes and a l k y n e ~ ~ ~ .~ but a fourth report of the reaction between cyclo-pentene and B2C14 indicates tr~ns-addition.~~' The cis-isomer of C1,B CH CH BCl, formed from B2C14 and acetylene is partially converted to the trans-isomer by irradiati~n.,~' The reaction of BBr with oxides, sulphides or chlorides of other elements affords a general method of preparing anhydrous bromides ;96 sulphur and PhBBr react to give 3,6-diphenyl-1,2,4,5-tetrathiadiborinan a member of a new cyclic boron-sulphur system.With Ph,CX (X = F Cl OH or OMe) two or more moles of BF to form Ph3CB,F7; no mixed fluoroborates or fluoro-anions other than BF4- and B2F7- were detected in this or in the reaction97b of Bun4NX (X = C1 Br or I) with BF,. There is fresh evidence too to support the contention that oxo-trifluoroborates of the type M"[OBF3] do not exist under aqueous condi-tions ;97c however water-soluble fluoropolyborates ofthe type M',B,03(0H)F4 have been described.97d Etherates of BF of the type F,B,OR (R = Pri Bus, or But) decompose with cleavage of the ether and formation of ROH,BF and the polyolefin;97e BCl and BI also cleave ether^,^^.^ but give ROBX and RX (X = C1 or I) of which ROBI subsequently decomposes to BI, B203, and RI.The molecular nature of the adduct H,O,BF has been demonstrated by the n.m.r. spectra of acetone solutions at low temperatures.97g The proper-ties of urea and thiourea adducts of BF favour nitrogen (rather than oxygen or sulphur) as the site of co-ordination ;97h a new type of six-membered hetero-cyclic compound assigned the structure (17) has been obtained by the dis-proportionation of covalent adducts of sym-dialkylureas with BCl,. Appropriately substituted pyridines give relatively stable boron free 92 J. PleSek S. Heirnhnek B. Stibr and F. Hanousek Coll. Czech. Chem. Comm. 1967,32 1095. 93 P. L. Timrns J . Amer. Chem. Soc. 1967,89 1629. 94 R.Koster and W. Fenzl Angew. Chem. Internat. Edn. 1967,6,802. 95 (a) R. W. Rudolph J . Amer. Chem. SOC. 1967,89,4216; M. Zeldin A. R. Gatti and T. Wartik, J . Amer. Chem. SOC. 1967 89 4217; (b) T. D. Coyle and J. J. Ritter J . Amer. Chem. SOC. 1967 89, 5739; (c) H. K. Saha L. J. Glicenstein and G. Urry J . Organometallic Chem. 1967 8 37. 96 M. F. Lappert and B. Prokai J . Chem. SOC. (A) 1967 129; P. M. Druce M. F. Lappert and P. N. K. Riley Chem. Comm. 1967,486. 97 (a) P. J. Burchill S. Brownstein and A. M. Eastham Canad. J . Chem. 1967,45,17; (b) S. Brown-stein ibid. p. 2403; (c) H. Siebert and H. H. Eysel Z . Naturforsch. 1967,22b 556; (d) L. R. Batsanova and V. A. Egorov Russ. J . Inorg. Chem. 1967,12 165; (e) E. F. Mooney and M. A. Qaseem Chem. Comm. 1967 230; v) T.P. Povlock Tetrahedron Letters 1967 4131; (9) R. J. Gillespie and J. S. Hartman Canad. J . Chem. 1967,45,859; (h) N. N. Greenwood and B. H. Robinson J . Chem. SOC. (A), 1967.511 The Typical Elements 24 1 radicals,98 e.g. (18) (R = CH,Ph Me Et Pr" Pri or But; x = 1.5-3). The i.r. spectra of boron-nitrogen compounds have been analysed in terms of the structural units present.99a Spectroscopic properties99b of some boranes containing one two or three NCO or NCS groups support the formulation BaN C :X (X = 0 or S) in all cases and suggest the following n-bonding sequence B-F > B-NCO > B-NCS > B-Cl. The properties of organo-boron azides of the type RR'BN, prepared from RR'BC1 and LiN, and of their 1 1 pyridine complexes are reported ;loo thermal decomposition pro-duces borazines and diazadiboretanes ([RB-NR],) by migration of an organic group from the boron to the a-nitrogen atom the migratory aptitude being m-CF3C6H > o-to1 > naph > Ph > p-C1C6H4 > Me > p-tol.The cyano-boron compounds (Me,N),BCN [Me,NB(CN),], Et,NB(CN),, Me,NB(CN),,L (L = LiCN Me,SiCN or NMe,) and AgB(CN) have been prepared from the interaction of appropriate B-Cl derivatives with AgCN, LiCN or Me,SiCN; the tendency of such species to polymerise has been discussed.101 At 160-200" the 1 l adduct of Ph,C:NH with Me,B loses methane to form the azomethine derivative Ph,C:N-BMe, judged to be monomeric in the vapour,lo2" but Et,B and Ph,B do not respond similarly to Ph2C NH. The products of the reaction of acetoxime with MMe (M = B, Al Ga In or T1) are methane and a compound [Me,C:NOMMe,], which appears to be dimeric when M = Al Ga or In but monomeric in the vapour and associated in the condensed phase when M = B; of the possible modes of association that involving a six-membered B-0-N ring structure seems most likely.102b In the light of thermodynamic details for the monomer-dimer equilibrium determined by llB n.m.r.spectroscopy for the aminoboranes R2N*BX2 R,N*BXMe and R'HN-BMe (R = Me Et or Bu; X = H F C1, or Br ; and R' = H or Me) the influence of steric and electronic factors on the equilibrium has been re-evaluated. Hydrazinoboranes R,B - NH - NMe, (R = Bun or Ph) and R,B-NH-NH*BR (R = Me Et or Bun) result104 from the reaction of haloboranes R,BX with N-silylhydrazines; a deep blue inter-mediate may be an azoborane such as R,B*N:N*BR,.For boron nitride as for graphite the anomalous compressibility in the basal plane has been attributed to a more localised type of bonding under the influence of compre~sion.'~~ In addition to the chelating poly( 1 -pyrazolyl) borate anions," so-called pyrazaboles with the general formula (19a) have ) " R. Koster H. Bellut and E. Ziegler Angew. Chem. Internat. Edn. 1967 6 255. '' (a) A. Meller Organometallic Chem. Rev. 1967,2 1 ; (b) M. F. Lappert and H. Pyszora J . Chem. loo P. I. Paetzold P. P. Habereder and R. Miillbauer J . Organometallic Chem. 1967 7 45 514 lo' E. Bessler and J. Goubeau Z . anorg. Chem. 1967,352,67. lo* (a) I. Pattison and K. Wade J . Chem. SOC. (A) 1967 1098; (b) J. R. Jennings and K.Wade, lo3 H. Noth and H. Vahrenkamp Chem. Ber. 1967,100 3353. lo4 K. Niedenzu P. Fritz and W. Weber Z . Naturforsch. 1967,22b 225. lo' L. Pauling Proc. Nut. Acad. Sci. U.S.A. 1966,56 1646. SOC. (A) 1967,854. P. I. Paetzold and P. P. Habereder ibid. 1967,7 61. J . Chem. SOC. (A) 1967;1333 242 A. J . Downs G. M . Sheldrick and J . J . Turner been prepared by the interaction of boranes and borane complexes with pyrazoles the properties and reactions of these compounds imply that the ring system has considerable stability. By contrast with the 1-borylpyrazole fragment the electronically similar but geometrically disparate l-boryl-imidazole fragment (19b) associates in the form of polymers rather than Y discrete heterocycles.'06b In 1,8,10Q-triazaboradecalin the BN, C,NB and CNHB units are virtually coplanar and this together with the B-N bond lengths of 1.40-1.43 4 is assumed to reflect the influence of n-bonding between boron and nitrogen.' O7 Newly synthesised borazines include perfluoro-vinyl derivatives' 08' and compounds with an optically active organic sub-stituent attached to the ring.108b The measured heats of hydrolysis of some borazine~'~~" have been used to calculate standard heats of formation (for borazine AHf = -204.9 kcal./mole in contrast with a previous estimate), from which the B-N bond energy has been found to decrease in the order H,B,N,Me > H,B,N,H > Cl,B,N,Me > Cl,B,N,H,.Ionisation po-tentials of some methyl-substituted borazines measured by electron impact. ' 09b decrease in the order H,B,N,H > Me,B,N,H > H,B,N,Me > Me3B3N3Me3 but show less variation with methyl substitution than do those of corresponding benzenes; the values are more sensitive to N - than to Emethyl substitution.Photolysis of gaseous mixtures of borazine with oxygen or water leads to B-substituted H3N3B3H20H and (H3N3B3H2)20 ; (a) S. Trofimenko J . Amer. Chem. SOC. 1967 89 pp. 3165 4948; (b) S. Trofimenko ibid., p. 3903. lo' G. J. Bullen and N. H. Clark Chem. Comm. 1967,670. lo* (a) A. J. Klanica J. P. Faust and C. S. King Inorg. Chem. 1967,6,840; (b) D. T. Haworth and Io9 (a) B. C. Smith L. Thakur and M. A. Wassef J . Chem. SOC. (A) 1967 1616; (b) P. M. Kuznesof, G. F. Gould Chem. and Znd. 1967,2113. F. E. Stafford and D. F. Shriver J . Phys. Chem.1967,71,1939 The Typical Elements 243 the products of the analogous reactions with NH and ROH (R = Me or Et) are H,N,B,H,NH2 and H,N3B,H20R respectively.' l o The cyclic com-pound [(CF,),AsBH,], possibly with [(CF3),AsBH2I4 is formed from (CF,),AsH and B2H6 at 4 - 5 O . l '' The "B n.m.r. spectra of aqueous solutions of boric acid and alkali-metal meta-and poly-borates have been used' 13' to obtain information (including pK values) about the polymerisation equilibria ; formation constants have also been measured' 13' for the complexes of various organic polyhydroxy-compounds with borate ion. Alkoxy-boron dihalides ROBX (X = F or Cl), prepared by the reaction of BX with (RO),B or with R',Sn(OR), afford114' with pyridine both 1 1 and 1 2 complexes (ROBX to pyridine).The molecular weight and spectroscopic properties of the cyclohexane-soluble alkoxyboron difluorides suggest a trimeric structure with a six-membered B-0 ring. ' 14' The vibrational spectra of alkoxy-boron halides and of the compounds Me,BOH and MeB(OH) have been discussed in terms of competing n-bonding influences.' 14'9' Variations in the dipole moments of molecules of the type X2BOY and XB(OY) (X = F C1 and Me; and Y = H and Me) and of other substituted boranes have likewise been correlated with n-bonding effects ;' for the XB(OY) molecules a non-planar configuration is indicated. In the low-pressure reaction of gaseous boroxine with BX, (X = F C1 or Br) to produce HBX and B203 the rate increases in the order BF < BCl < BBr,; isotopic tracer studies establish that the boron atoms in H3B303 appear in the HBX whereas the boron atom in BX appears in the B203."' By treatment of sodium alkynyltrialkylborates e.g.Na' [Et,B - C iCMe] -, with acetyl chloride alkyl derivatives of the hitherto unknown 2,3-dihydro-1,2-oxaborole system e.g. (20) have been obtained.' l6 P-Keto-enolates of boron are produced by the insertion reaction of 0-C6H4o2BX (X = NEt,, NPri2 OEt or C1) with diketen;'17 P-keto-enolates of other elements have also been prepared in this way. A gaseous species thought to be HBS results"* from the action of H2S on boron at 1150-1300°; its lifetime appears comparable with that of SiF, and longer than that of HBO. The B-S bond energy in thioboranes (RS),B (R = Me Pr" Bun n-pentyl and Ph) is nearly constant (ca.90 kcal./mole), The crystal chemistry of borates has been re-analysed and classified. ' I o G. H. Lee jun. and R. F. Porter Inorg. Chern. 1967 6 648; M. Nadler and R. F. Porter, ibid. p. 1739. A. P. Lane and A. B. Burg J . Amer. Chem. SOC. 1967,89 1040. '12 G. B. Bokii and V. B. Kravchenko J . Struct. Chem. 1966,7,860. ' I 3 (a) R. K. Momii and N. H. Nachtrieb Inorg. Chem. 1967,6,1189; (b) J. M. Conner and V. C. Bulgrin J . Inory. Nucleur Chent. 1967 29. 1953 V. A. Nazarenko and L. D. Ermak Russ. J . Inorg. Chem. 1967,12 335. ( n ) W. Gerrard. E. F. Mooney. and W. G. Peterson. .I. Irioi-g. Yidetrr Chrm. 1967 29 943; (b) J. E. De Moor G. P. Van der Kelen and Z. Eeckhaut J . OrganometaZlic Chem. 1967 9 31; (c) J. E. De Moor and G. P. Van der Kelen ibid.1967 9 23. 114 'Is M. Nadler and R. F. Porter Inorg. Chem. 1967,6 1192. P. Binger Angew. Chem. Internat. Edn. 1967 6 84. J. R. Horder and M. F. Lappert Chem. Comm. 1967,485. 11* R. W. Kirk and P. L. Timms Chem. Comm. 1967,18 244 A. J . Downs G. M . Sheldrick and J . J . Turner according to the recently determined standard enthalpies of formation and vaporisation.'lg Several methods have been explored for the synthesis of boron-sulphur compounds some properties of which (e.g. complex-formation, oxidation and insertion reactions with isocyanates) are reported.'2Gu The B-S bond of a thioborane R,BSR' (R = Pr Bu or Ph; R' = Et or Bu) undergoes reversible addition120b to MeCN giving a dimeric product [R,B-N:C(Me)SR'], which in common with [Ph,C:N*BMe2],,102" pre-sumably contains a four-membered B-N ring.Heterocyclic rings containing boron carbon and sulphur result from the reaction of aminoboranes with a,o-dithiols aminoboranes and o-aminothiophenol give 5-membered hetero-cycles containing boron carbon nitrogen and sulphur."' BI or Bu",BI reacts with red selenium to give the new boron-selenium ring compounds 2,5-di-iodo- or 2,5-dibutyl-1,3,4-triselenadiborolan. 122 In the quantitative reaction of Me,NO with B-C and certain B-N bonds, b - X + ONMe -+ B-0-X + NMe (X = d- d ), a convenient method of analysing these groups has been found.'23 In addition to a fuller of the preparation and properties of CF,BBu" and CF,BF, there has appeared a report124b of the preparation of the heptafluoro-n-propyl compounds o-C6H402B*C,F7 and (Me,N),B*C,F from the corresponding boron halides and C,F,Li.The ready reaction of CO with trialkylboranes followed by oxidative hydrolysis of the product effects the migration of alkyl groups from boron to carbon the rate of this migration depending markedly on the reaction conditions and the nature of the organic groups.I2 Boron-carbon migration reactions are also reported for the anionic complexes derived from a-halovinylboranes which rearrange for example in \ / / \ \ the following way:'25b BPh =C Li \ =C BPh \ Numerous polycyclic molecules incorporating boron-carbon heterocycles '19 A. Finch P. J. Gardner and G. B. Watts Trans. Faruday SOC. 1967,63 1603. lZo (a) R. H. Cragg M. F. Lappert and B. P. Tilley J . Chem. SOC. (A) 1967,947; (b) B.M. Mikhailov, V. A. Dorokhov and I. P. Yakolev Bull. Acad. Sci. U.S.S.R. 1966 298. K. Niedenzu J. W. Dawson P. W. Fritz and W. Weber Chem. Ber. 1967 100 1898. lZ2 M. Schmidt W. Siebert and E. Gast Z . Naturforsch. 1967,22b 557. lZ3 R. Koster and Y. Morita Annalen 1967,704 70. 124 (a) T. D. Parsons J. M. Self and L. H. Schaad J . Amer. Chem. SOC. 1967,89,3446; (b) T . Chivers, Chem. Comm. 1967 157. (a) H. C. Brown and M. W. Rathke J . Amer. Chem. SOC. 1967,89 pp. 2737,2738,2740; H. C. Brown and E. Negishi. J . Amer. Chem. SOC 1967.89 5285 ( h ) G. Kobrich and H. R. Merkle. Angew. Chem. Internat. Edn. 1967 6 74; Chem. Ber. 1967 100 3371; G. Zweifel and H. Arzoumanian, J . Amer. Chem. SOC. 1967,89,5086 The Typical Elements 245 (e.9. 1-boraindane or 1-boratetralin) have been synthedsed by the pyrolysis of mixed arylalkyl- and arylcycloalkyl-boranes.' 26 Aluminium. The crystal structure of triphenylaluminium is similar to that of trimethylaluminium ;' 27a the centrosymmetric dimeric molecules contain coplanar bridging phenyl groups normal to the plane of the four-membered Al-C ring. The structure is reflected in the i.r. spectrum127b and heat of sublimation'27c of the compound. The presence of bridging phenyl groups is also implied127d by the low temperature 'H n.m.r. spectra of [Me,AlPh] and of Me,Al-Ph,Al mixtures in toluene. The effectiveness of phenyl as a bridging group seems therefore to have been misjudged in the past. Na[AlPh,] formed by the reaction of Na[AlEt,] with benzene in the presence of NaOR or PhNa, can be used to prepare phenylaluminium compounds.127e C,F,AlBr and (C,F,),AlBr have been prepared by cleavage of MeHgC,F with AlBr ; properties of these compounds which are dimeric in benzene include the ability to participate in olefin-insertion reactions.127f Reanalysi~'~~" of the crystal structure of trimethylaluminium gives slightly modified dimensions for the Me,Al unit which is significantly distorted from the idealised D, sym-metry. The molecular structure of [A1Me,],,C,H80 in the solid state'28b consists of a dioxan molecule with each oxygen co-ordinated to an aluminium atom the environment of which is more nearly trigonal than tetrahedral. In the solid phase [(n-C,H,),TiAlEt,] molecules contain Ti-Ti and Ti-A1 bonds and both titanium and aluminium atoms of one (n-C,H,),TiAlEt, unit are at bonding distances from a carbon atom of a n-C,H ring of the second unit.' 28c Heats of combustion and formation are reported ' 294 for the compounds R,AIH and R,AI (R = Et Pr" Bun and But) for the dissociation of [R,Al] enthalpies of 20.4 f 0.3 kcal./mole (R = Me)'29b and 16.9 f 0.2 kcal./mole (R = Et)'29c have been obtained by tensimetric and heat-of-dilution measurements respectively.Transalkylation occurs between organo-tin hydrides and aluminium trialkyls to form the corresponding tetra-alkyltin and dialkylaluminium hydride derivatives complexes formulated as [SbEt4][A1Et,C1,,] and [SbEt,][Al,Et,Cl,-,] result'30b from the reactions of SbCl or five-valent ethylantimony compounds with ethylaluminium compounds such as Et3Al and Et,AICl.Halogeno-methylalanes R,AlCH,X, are notable for their reaction' 3 1 with organo-lithium compounds R'Li giving R . Koster G. Benedikt W. Fenzl and K . Reinert. Anr7rrlrn. 1967 702 197. 1 2 ' ( n ) J. F. Malone and W. S. McDonald Chem. Comm. 1967,444; (b) H. F. Shurvell Spectrochim. Acta 1967,23A 2925; ( c ) N. N. Greenwood P. G. Perkins and M. E. Twentyman J . Chem. Soc. (A), 1967,2109; ( d ) E. A. Jeffery T. Mole and J. K. Saunders Chem. Comm. 1967,696; (e) H. Lehmkuhl and R. Schafer Annalen. 1967.705.32; (A R. D. Chambers and J. A. Cunninpham. J . Cheni. SOC. (C), 1967 2185 ; Tetrahedron Letters 1967 3813. (a) R. G. Vranka and E. L. Amma J . Amer. Chem. Soc. 1967,89 3121; (b) J. L. Atwood and G. D. Stucky J . Amer. Chem. Soc. 1967,89,5362; ( c ) P.Corradini and A. Sirigu Inorg. Chem. 1967, 6 601. 129 (a) S. Pawlenko Chem. Ber. 1967 100 3591 ; (b) C. H. Henrickson and D. P. Eyman Inorg. Chem. 1967,6 1461; ( c ) M. B. Smith J. Phys. Chem. 1967,71 364. (a) B. Schneider and W. P. Neumann Annalen 1967 707 7; (b) Y. Takashi and I. Aishima, J. Organometallic Chem. 1967,8 209; Y. Takashi J. Organometallic Chem. 1967 8 225. 131 H. Hoberg. Arinnkn. 1967. 703. 246 A. J . Downs G. M . Sheldrick and J . J . Turner Li+[R2R'A1-CH2X]- ; the aluminium-ylide R,R'AI-*CH; may be an intermediate in the subsequent elimination of LiX to form R,Al-CH,R' and RR'Al CH,R. On the evidence of low-temperature n.m.r. measurement^,'^^" 1 1 adducts of MMe with Me,Si[N PMe3I2 exhibit a temperature-dependent exchange (31) when M = A1 or Ga but not when M = In with this development a new Me .,Me - s1 -MMe Me,Md Me,P:NL/ 'N:PMe Me,P:N' 'N PMe, Me,Si Br ,Br /*I\ Me,P :N ,N PMe, Br/ A* Br Ph ,Ph m ' b - S i M e , principle of 'stationary and oscillating acceptors' has been enunciated.The interaction of organoaluminium compounds with polydentate ligands such as R,N*[CH2],-NR2 (R = Me Et) and b i ~ y r i d y l ' ~ ~ ~ has been investigated. A series of dimeric dialkyl- and diaryl-aluminium derivatives [R,AlBD] has been prepared'32' by the reactions of R,Al with bidentate ligands BDH featuring 0-H and N-H functional groups (e.g. BDH = Me,N- [CH,],*OH); structures with bridging through both the donor atoms of BD are favoured except for BD = H,N.[CH,],*O- when Al-0-A1 bridging is indicated.The solution enthalpies of formation of a number of sulphide complexes Me,Al,L vary but little with L; the apparent donor abilities of the ligands which decrease in the order (CH,),S - (CH2@ > Et2S - Me,S > (CH2)$ > H m C H M e are probably determined more by inductive and ring-strain effects than by steric factors.'"' In the formation of 1 l complexes Et,AlX,L (L = Me,N py or THF) the relative acceptor strengths Et,AlF < Et,AlCl < Et,AlBr < Et,AlI have been deduced from the 'H n.m.r. spectra.132d Heats of formation are also reported'32e for PhCN complexes of organo-aluminium compounds R,AlX,- (R = Me or Et; X = C1 Br or I ; n = 1-3); together with spectroscopic data these support the following order of acceptor power R,Al < R,AlX < RAlX,.The forma-tion and subsequent decomposition with methane-elimination of l l adducts of acry10nitrile'~~f and benzyl ~ y a n i d e l ~ ~ g with Me,AlCl, are described. '32 (a) H. Schmidbaur and W. Wolfsberger Angew. Chem. fnterntrr. Edn 1967 6 448; (h) K.-H. Thiele and W. Bruser Z . crnor!/. Chem. 1967 349 33; ( c ) T. J. Hurley M. A. Robinson J. A. Scruggs. and S. 1. Trotz. Iriorg. Ch~m 1967. 6. 1310 ( d ) C. A. Smith and M. G. H. Wallbridge. J. Cheni. SOC. (A) 1967 7; ( e ) K. Starowieyski S. Pasynkiewicz and M. Bolesawski J . Organometallic Chem., 1967 10 393 cf S. Pasynkiewicz and W. Kutan. ibid. p. P23 ; (9) S. Pasynkiewicz K. Staiowieyski, and Z. Rzepkowska ibid. p. 527 The Typical Elements 247 Complexes of Et,Al with various ligands (e.g.Et,N py or THF) show remark-able electrical conductivities suggesting the presence of ions ;',,' 'H n.m.r. spectra indicate that ligand exchange is generally rapid,',,' though such exchange between MeAlCl,,OPr' and AIC13,0Pr' appears to require 'free' Pr',O molecules as an essential agent.',,' Raman133c and 'H n.m.r.133d studies of the redistribution of ethyl and chlorine groups in the Et,AI-AlCl, system lead to the following conclusions (i) in the presence of ether Et,AlCl is preferentially produced and (ii) on the n.m.r. timescale exchange of ethyl groups between [Et,Al) and [Et,AlCl] is rapid at room temperature but slow at temperatures < -2O"c; no evidence of the mixed dimer Et,AI(Et,Cl)AlEt has been found. The i.r. spectra of the 1 1 fluoride com-plexes MF,AlR (M = Na or K; R = Me or Et) do not the presence of discrete [R,AlF] - ions.Alkaline-earth complexes M[A1Et4], (M = Ca Sr or Ba) result'34b from the reaction of M(OR) with Et,Al or of the metal with Et,Hg and Et,Al ; their properties indicate little salt-like character except perhaps when M = Ba. Numerous 1 1 adducts of Me,Si*N:PR (R = Me Et or Ph) with tri-alkyls,135' t r i a r y l ~ ' ~ ~ ' or trihalide~'~'' of aluminium gallium or indium MY,, have now been described; a planar arrangement is suggested for the central framework of these systems (22) which is isoelectronic with that of trisilylamine. Pyrolysis of the complex'35b formed from AlBr and Me,Si*N PMe, eliminates Me,SiBr to form the dimer [Me,P:N*AlBr,] which is pre-sumed to contain a four-membered Al-N ring (23) by analogy with the 'isosteres' [Me,SiN* SiMe,] and [Me,SiO AlMe,] ,.[Me,P N* AlMe,] is formed from the dibromo-compound with MeLil 3 s b or by methane-elimina-t i ~ n ' ~ ' ~ from the 1 1 adduct of Me,Al with Me,P:NH. Similar structures are postulated for the azomethine derivatives [Ph,C N AIR,] (R = Me Et or Ph) formed'35d by the loss of RH from the 1 1 adducts of Ph,C NH with AlR,. However pyrolysis of the MPh adducts (M = A1 or Ga) of Me,Si.N:PPh, in the elimination of benzene and formation of derivatives of two novel five-membered heterocyclic systems (24). From the reaction of Me,AlI with R,SiN (R = Me or Ph) the azides MeAl(N,), MeAlIN and Me,AlN3 are formed of which Me,AlN, being trimeric in benzene is presumed to have a cyclic structure with Al-N-A1 bonding.'36a The i.r.spectra of the thiocyanates Et,MSCN (M = Al Ga or In) which are also trimeric in benzene are consistent with a similar six-membered M-S ring.'36b The compounds are produced from MEt and (SCN),. Aluminium free radicals ' 3 3 (a) Y. Takashi Bd1. Chem. SOC. Jrcprcn 1967,40,612; ( h ) A. C. M. Wanders and E. Konijnenberg, Tetrahedron Letters 1967,2081; ( c ) R. Tarao and S. Takeda Bull. Chem. SOC. Japan 1967,40 650; (d) K. Hatada and H. Yuki Tetrahedron Letters 1967 5227. 134 (a) K. Mach Coll. Czech. Chem. Comm. 1967,32 3777; (b) H. Lehmkuhl and W. Eisenbach, Annalen 1967 705 42. 135 (a) H. Schmidbaur and W. Wolfsberger Chem. Ber. 1967,100 pp. lO00 1016; (b) H. Schmid-baur W. Wolfsberger and H. Kroner ibid. p. 1023; (c) H.Schmidbaur and G. Jonas Angew. Chem. Internat. Edn. 1967,6,449; (d) K. Wade and B. K. Wyatt J . Chem. SOC. (A) 1967 1339. 136 (a) N. Wiberg W.-Ch. Joo and H. Henke Inorg. Nuclear Chem. Letters 1967 3 267; (b) K. Dehnicke Angew. Chem. Internat. Edn. 1967,6,947 248 A. J . Downs G. M . Sheldrick and J . J. Turner AlX (X = Ph or Cl) formed for example by pyrolysis of Ph,C*A1X2 are stabilised by co-ordination woth pyridine.' 37 The interaction of the trimethyls Me,M (M = Al Ga or In) with Me,NO, Me,PO or Me2S0 gives rise1,* to stable distillable 1 1 adducts Me,M'-0-MMe (M' = N P or S). The redistribution behaviour and optical inversion of some aluminium P-diketonates have been examined by 'H n.m.r. technique^.'^^" In absolute ethanol the 8-quinolinol (HQ) chelates of aluminium AlQ2+ and A1Q2+ appear to exist in two forms which differ in the composition of the co-ordination shell of the aluminium;139b the existence of polynuclear forms of A1Q2 + and A1Q2 + is also indicated.The chemistry of aluminium hydride has been reviewed;'40" the heat of formation of AlH, AH; 298 = +2.73 & 0.20 kcal./mole and derived standard free energy'40b show that AIH is thermodynamically unstable with respect to the elements and lead to E(A1-H) = 79 kcal./mole. In crystalline LiA1H4 the Li+ ions act as bridges between the tetrahedral AIH4- with Li+.---H distances substantially shorter than those in LiH ; X-ray powder methods indicate141b that Na,A1H6 (for which various syntheses have been d e ~ e l o p e d ) ~ ~ " is isostructural with Na,AlF6.The properties of Mg(AlH,),, prepared by thereaction of M'AlH (MI = Li or Na) with MgX (X = C1 or BH,) differ significantly from those previously reported.I4ld According to its molecular weight dipole moment and 'H n.m.r. spectrum H Al,NMe is monomeric in non-polar solvents.'42n The formation of complex ions in the reaction of LiAlH with AlCl in ethereal solution is suggested by conducto-metric measurements. THF complexes with the composition AlHX,, 2THF and AIH2X,2THF have been described. 142c The molecules AlF AlF, and Al,F, trapped in matrices have been characterised by their i.r. spectra;'43a from the measured heats of sublimation of AlF and A12F6 the enthalpy of dimerisation of AIF,(g) is found to be -49 & 3 k ~ a 1 . l ~ ~ ~ Transpiration measurements of the reaction between aluminium and AlCl vapour at 800-1000"~ lead143c to thermodynamic 13' H.Hoberg and E. Zicgler Angew. Chem. Internat. Edn. 1967,6,452; E. Zicgler G. Fuchs and 13* F. Schindler and H. Schmidbaur Chem. Ber. 1967,100 3655. 13' (a) J. J. Fortman and R. E. Sievers Inorg. Chem. 1967 6 2022; (b) W. E. Ohnesorge J . Inorg. Nuclear Chem. 1967,29,485. I4O (a) K. N. Semenenko B. M. Bulychev and E. A. Shevlyagina Russ. Chem. Rev. 1966,.35, 649; (b) G. C. Sinke L. C. Walker F. L. Oetting and D. R. Stull J . Chem. Phys. 1967 47 2759. 14' (a) N. Sklar and B. Post Inorg. Chem. 1967,6,669; (b) V. Subrtova Coll. Czech. Chem. Comm., 1966 31 4455; L. I. Zakharkin V. V. Gavrilenko L. M. Antipin and Yu. T. Struchkov Russ. J . Inorg. Chem. 1967 12 607; (c) M.Mamula and T. Hanslik Coil. Czech. Chem. Comm. 1967 32, 884; V. V. Gavrilenko G. A. Egorenko L. M. Antipin and L. I. Zakharkin Russ. J . Inorg. Chem., 1967,12 317; (d) J. PleSek and S. Hefmanek Coll. Czech. Chem. Comm. 1966,31,3060. 14' (a) D. G. Hendricker and C. W. Heitsch J . Phys. Chem. 1967 71 2683; (b) S. M. Arkhipov and V. I. Mikheeva Russ. J . Inorg. Chem. 1966 11 1073; (c) D. L. Schmidt and E. E. Flagg Inorg. Chem. 1967,6 1262. 143 (a) A. Snelson J . Phys. Chem. 1967,71 3202; (b) A. Buchler E. P. Marram and J. L. Stauffer, J . Phys. Chem. 1967,71,4139; (c) B. J. Chai H. C. KO M. A. Greenbaum and M. Farber J . Phys. Chem. 1967,71,3331. H. Lehmkuhl 2. anorg. Chem. 1967,355 145 The Typical Elements 249 functions for the formation of A1C12(g) and A12C14(g).In addition to the 1 l complexes of alkali halides MX with AlX, thermal analysis of such systems implies'44 the formation of the complexes MA12X7 (M = Na X = I ; M = K Rb or Cs X = Br) and NaAl,I,,. Molecular complexes of the aluminium trihalides recently investigated include those formed with pyri-dine,145u ether and s ~ l p h i d e ' ~ ~ ~ ligands which have been characterised by phase diagrams and thermochemical tensimetric i.r. or n.m.r. measurements ; interaction between the halogen and a-hydrogen in 4-ethylpyridine com-p l e x e ~ ' ~ ~ ~ may represent a hitherto neglected factor in discussions of donor and acceptor strengths. It is also suggested'45' that for a strong acceptor like AlBr, differences in the donor properties of ethers due to structural variations are levelled out.Conductivities of AlCl solutions in MeCN are interpreted'45d in terms of the reaction : 2AlC1 + 4MeCN -+ [A1Cl2(MeCN),]+ + [AlCl,]-, involving so-called 'co-ordination disproportionation.' The preparation and properties of AlSeX (X = C1 Br or I) have been de~cribed.'~~ Gallium Indium and Thallium. Unlike SnI, Ge12 and SO2 InBr cleaves the metal-metal bonds of the anions [M2(C0),,]2- (M = Cr W) to give'47 species of the type (OC),M,InBr,2 -. According to polarographic bivalent thallium is formed at a dropping-mercury electrode when 2,2'-bipyridyl complexes of thallium(I1r) in O.~M-KNO solution are reduced at low thallium concentrations ( < l m ~ ) and pH > 5. A novel organo-thallium free radical (25) formed from the corresponding 8-acetatomercury free radical and T1(OCOC3H7), has been characterised in solution by its e.s.r.spectrum.'48b The results of indium-amalgam p~larography'~~' of indium solutions in Me M e m M e Me 144 G. Boef H. B. Slot R. A. W. van Leeuwen H. Wessels and J. W. van Spronsen Z. anorg. Chem. 1967,353,93; C. T. H. M. Cronenberg and J. W. van Spronsen ibid. 1967,354,103. 145 (a) J. Wilson and I. J. Worrall J . Chem. SOC. (A) 1967 392; Inorg. Nuclear Chem. Letters, 1967 3 57; T. N. Huckerby J. W. Wilson and I. J. Worrall Chem. Comm. 1967 1190; (b) R. L. Richards and A. Thompson J . Chem. SOC. (A) 1967 pp. 1244,1248; ( c ) I. P. Romm E. N. Gur'yanova, and K. A. Kocheshkov Doklady Chem. 1966 166 180; (d) W. LibuS and D. Puchalska J . Phys. Chem. 1967,71,3549.146 P. Palvadeau and J. Rouxel Bull. SOC. chim. France 1967,2698. 14' J. K. Ruff Inorg. Chem. 1967,6 2080. 14* (a) 0. Farver and G. Nord Chem. Comm. 1967 736; (b) A. B. Shapiro and E. G. Rozantsev, Bull. Acud. Sci. U.S.S.R. 1966 1593; ( c ) J. B. Headridge and D. Pletcher Inorg. Nuclear Chem. Letters 1967,3,475 250 A. J. Downs G. M. Sheldrick and J. J. Turner MeCN show that with respect to the reduction In' + In' indium(1) species are appreciably more stable in MeCN than in water ; an equilibrium constant of ca. 0.3 is deduced for the process : In3+ + 2In(Hg) + 3111' + 2Hg in MeCN. A review has appeared on the chemistry of organo-gallium -indium and -thallium compounds. 149 Organo-gallium dihalides of the type [RGaX,], (R = Et Pr" C7H15" or cyclohexyl; X = C1 or Br) result from the anti-Markownikoff addition of HGaX to olefins ; the Ga-C bond is cleaved by iodine in ether.' 500 Dialkylgallium fluorides R,GaF are conveniently synthesised by treatment of Me,SnF with R3Ga or R,Ga,OEt,; a six-membered ring structure with Ga-F-Ga bonding is indicated by the properties of Me,GaF and Et,GaF which are trimeric in ben~ene.'~'' Four-membered Ga-N rings analogous to (23) are the most likely framework for the azomethine compounds [R-CH :N-GaEt,] (R = Ph or But) and [Ph2C:N*GaR2] (R = Me Et or Ph) formed by elimination of hydro-carbon from the 1 1 adducts RCN,GaEt and Ph,C :NH GaR, res-pe~tively.'~~' A six-membered Ga-N ring is suggested for [Et,GaN3] by cryoscopic and spectroscopic data. ' 50d Dimeric organo-gallogermoxanes [R2Ga*OGeR',] (R,R' = Me Ph) are produced150' by the reactions of R,GaCl with R',GeOLi or of R,Ga with R',GeOH ; preliminary analysis confirms the presence of a planar four-membered Ga-0 ring in crystalline [Me,Ga OGeMe,], and similar structures are likely for [Me2M OGeMe,], (M = A1 or In) also reported.Steric and electrostatic details are considered to be more relevant than p n d,-bonding to the stereochemistry of these molecules. Dimethylindium halides Me,InX (X = F C1 Br and I) have been prepared.' 50e ' la Other newly described organo-indium compounds are Me,InY [Y = 8-hydroxyquinolinate o-nitrophenoxide acetate 1,l-bis(tri-fluoromethyl)ethoxide] and adducts of Me,InX (X = C1 or I) with Ph3P and ~yridine;'~'" Et,InX (X = C1 or Br) and EtInS;I5lb and Et,InSCHPh, which probably has a cyclic structure with bridging sulphur atoms since it is dimeric in benzene.' In the crystalline complex diethyl(salicyla1dehydato)thallium (111), the six-co-ordinate thallium atoms are linked via four-membered TI-0 rings in the form of infinite chains;'52" the C-T1-C angle is 172".The crystal structure of the 1,lO-phenanthroline complex of Me,T1+C1O4-149 K. Yasuda and R. Okawara Organometallic Chem. Rev. 1967,2,255. lS0 (a) H. Schmidbaur and H.-F. Klein Chem. Ber. 1967 100 1129; (b) H. Schmidbaur H.-F. Klein and K. Eiglmeier Angew. Chem. Internat. Edn. 1967 6 806; (c) J. R. Jennings and K. Wade, J . Chem. SOC. (A) 1967 1222; J. R. Jennings 1. Pattison K. Wade and B. K. Wyatt ibid. 1967 1608; (d) J. Muller and K. Dehnicke J .Organometallic Chem. 1967,7 P1; (e) B. Armer and H. Schmidbaur, Chem. Ber. 1967,100,1521. 15' (a) H. C. Clark and A. L. Pickard J . Organornetallic Chem. 1967 8 427; (b) K. Yasuda and R. Okawara Inorg. Nuclear Chem. Letters 1967,3 135; (c) H. Tada K. Yasuda and R. Okawara, ibid. p. 315. lS2 (a) G. H. W. Milburn and M. R. Truter J . Chem. SOC. (A) 1967 648; (b) T. L. Blundell and H. M. Powell. Chern. Cornm. 1967 54 The Typical Elements 25 1 reveals not only a bent Me-TI-Me unit (~(2-Tl-c = 168”) but also a peculiar six-co-ordinate environment for the thallium best described as a distorted pentagonal bipyramid with one equatorial site vacant.”2b The following new diorgano-thallium derivatives are reported Me,TlY where Y is SPh OPh o-OC,H,Cl or BPh4;153“ dithiophosphinates R2Tl(SSPR’2) and dithiocarbamates R,Tl(SSNR’,) where R and R’ are Me Et or Ph;153b mixed diorgano-thallium chlorides RR’TICl where R and R’ are Me Et or Ph;153c pentafluorophenyl compounds (C6F5)2T1X (X = F C1 Br OCOMe, OCOPh or OCOC,F,) and their complexes with Ph,PO 1,lO-phenanthro-line and 2,2’-bipyridy1.’53d In numerous cases these compounds are judged to be associated either halogen oxygen sulphur or carboxylate acting as bridging groups.Monoalkylthallium derivatives have been synthesised for the first time by the reaction : R,TIX + HgX - RTIX + RHgX, in which R is Me or Et and X is a carboxylate or oxinate;’53e the species RTKOCOPr’) (R = Me or Et) like Et,TIOCOPr‘ are dimeric in benzene. Complexes of the type M,[R,TlX,] M[R2TlX2] M2[RTlX4J and M[RTlX,] (M = a univalent cation e.g.Ph4As+ Bun4Nt; R = Me or Ph; X = C1 Br, I or SCN) are formed from MX and either R2TlX or RTlX ; the behaviour of these complexes in methanol or acetone solution is consistent with the presence of organo-thallium anions.’ 531 The thermodynamic properties of crystalline TlC5H5 = 23.85 k 0-6 kcal./mole) determined from the heat of reaction of aqueous TlOH with gaseous C5H6 show that the different be-haviours of TlC5H5 Fe(C5H5)2 and Mg(C,H,) with respect to hydrolysis depend principally on the free energies of formation of the metal hydroxides, and so reveal little about the type or strength of the C,H,-metal bond.’’, The stability constants of the 1 1 complexes of the M3 + ion (M = Ga In, or T1) with a number of polyamino-carboxylate anions decrease”’ in the order TI >> In > Ga.With unidentate ligands L In(SCN), which has the properties of a thiocyanate-bridged polymer gives adducts with the com-position In(SCN),,3L while the species In(SCN) en and In(SCN) bd1.’ (bd = 1,lO-phenanthroline or 2,2’-bipyridyl) have been isolated from the reaction with bidentate ligands. ’ The vibrational spectra of some crystalline thallium complexes of the types M’TlX and M1,TIX are consistent with the presence of tetrahedral TlX,- and octahedral TlX,3 - ions.” 7a The formation (a) H. Kurosawa K. Yasuda and R. Okawara Bull. Chem. Soc. Japan 1967. 40 861; (b) F. Bonati S. Cenini and R. Ugo J. Organometallic Chem. 1967,9,395; (c) M. Tanaka H. Kurosawa, and R. Okawara Inorg. Nuclear Chem.Letters 1967 3 565; (d) G. B. Deacon J. H. S. Green and w. Kynaston J . Chem. Soc. (A) 1967 158 G. B. Deacon. Austral. J . Chem. 1967. 20. 459 (e) H. Kurosawa and R. Okawara J . Organometallic Chem. 1967 10 211; Inorg. Nuclear Chem. Letters 1967,3,21,93; v) G. Faraglia L. R. Fiorani B. C. L. P e p and R. Barbieri J. Orgmometallic Chem. 1967 10 363; Inorg. Nuclear Chem. Letters 1966 2 277. 154 H. Hull and A. G. Turnbull Inorg. Chem. 1967,6,2020. 155 G. Anderegg and E. Bottari Helv. Chim. Acta 1967 50,2341 2349. 15’ (a) T. G. Spiro Inorg. Chem. 1967 6 569; (b) E. N. Deichman and V. V. Tsapkin Russ. J. 153 S. J. Patel D. B. Sowerby and D. G. Tuck J . Chem. Soc. (A) 1967 1187. Inorg. Chem. 1967.12 159 252 A. J . Downs G. M . Sheldrick and J . J . Turner of indium fluoride complexes [InFJ3-" (x = 1-6) has been explored in the solid phase and in aqueous solution,'57b wherein hydrolysis gives rise to anionic species of the type [InFx(OH)6,]3 -.From the equilibrium diagrams of the systems GaC1,-SeCl and GaC1,-TeCl, the formation of the com-pounds MCl,,GaCl and MC1,,2GaC13 (M = Se or Te) is inferred.lS8 Con-ductivity and i.r. spectral properties have been used to interpret the nature of complexes (i) of InCl with bi- and tri-dentate nitrogen donors,'59a and (ii) of MX (M = Ga or In ; X = C1 Br or I) with arylphosphine ligands;159b the con-clusions are not always free from ambiguity159b in distinctions between mole-cular and ionic structures. In the co-ordination compounds InI,bipy,2EtNH2, In,I,,6EtHN2 and In,14,2bipy,4EtNH (bipy = bipyridyl) the reducing be-haviour of the indium is enhanced; evidently bipyridyl does not stabilise the lower oxidation states of indium.'59c Group IV.-Carbon.Diamond has been synthesised with a hexagonal structure16' which has also been shown to be present in some meteorite diamonds. Organometallic acetylene derivatives have been reviewed. la Pure Li,C has been prepared and has been shown to be isostructural with Rb202.161b The photolysis of NCN at 1 4 " ~ in argon or nitrogen matrices yields CCl in the presence of C12,162and HCCl in the presence of HC1;16,' both molecules were identified by the i.r. spectra of isotopically substituted species. The planarity of CH has been confirmed similarly,162c and the product of the reaction between lithium atoms and CCl or BrCCl in a matrix has been identified as CC13.16," A high frequency discharge in CS vapour produces CS identified by i.r.on quenching at - 1 9 0 " ~ ' ~ ~ " and also trapped as SCSe SCTe SCCl, SCBr, or SCI,. Similarly CSe has been trapped as SeCS or SeCTe.'63b C03 has been formed in a matrix by the reaction of oxygen atoms with C02,16,= and C03- identified by e.s.r. of y-irradiated single-crystal calcite ;164b HCN- has also been identified by e . ~ . r . l ~ ~ ' E.s.r. evidence for CS2- [bond angle probably ca. 141" (cf. CO,- 121")] is obtained by the reaction of Na or K atoms with solid CS2 at 77°~.165 (C6F5)3C+, formed by protonation of (C6F5)3COH in very strong acids is less stable than (C6H5)3C+.'66 Rotational analysis of the absorption spectrum assigned lS8 P.I. Fedorov and L. P. Khagleeva Russ. J . Inorg. Chem. 1966,11 1166. 159 (a) R. A. Walton J . Chem. SOC. (A) 1967 1485; (b) A. J. Carty Canad. J . Chem. 1967,45 345, 3187; (c) A. P. Kochetkova and 0. N. Gilyarov Russ. J . Inorg. Chem. 1966,11,662. F. P. Bundy and J. S. Kasper J . Chem. Phys. 1967,46,3437. 16' (a) W. E. Davidsohn and M. C. Henry Chem. Rev. 1967,67 73; (b) R. Juza V. Wehle and H-U. Schuster Z . anorg. Chem. 1967,352 252. 16' (a) D. E. Milligan and M. E. Jacox J . Chem. Phys. 1967,47 703; (b) M. E. Jacox and D. E. Milligan ibid. p. 1626; (c) L. Andrews and G. C. Pimentel ibid. p. 3637; (d) L. Andrews J. Phys. Chem. 1967,71,2761. 163 (a) R. Steudel Z . Naturforsch. 1966 21b 1106; (b) R. Steudel Angew. Chem. Internat. Edn., 1967 6 635.164 (a) N. G. Moll D. R. Clutter and W. E. Thompson J . Chem. Phys. 1966 45 4469; (b) R. A. Serway and S. A. Marshall ibid. 1967,47,868; (c) K. D. J. Root M. C. R. Symons and B. C. Wheather-ley Mol. Phys. 1966 11 161. 16' J. E. Bennett B. Mile and A. Thomas Trans. Faraday SOC. 196h. 63. 362. 16' G. A. Olah and M. B. Comisarow J . Amer. Chem. SOC. 1967,89 1027; R. Filler C-S. Wang, M. A. McKinney and F. N. Miller ibid. p. 1026 The Typical Elements 253 to FzCN in the flash photolysis of CF,NCF has enabled the ground-state molecular structure to be derived.167a A study of the dissociation equi-librium of F,CNO into CF and NO at 1600-2500"~ leads to the value AH; (F,CNO) = -15-7 k~al./mole.'~~' D (F,C-CF,) = 96.5 & 1.0 kcal./ mole has been calculated from the equilibrium constant for the reaction between C2F6 and Br by a third-law method.'67" The crystal structures of a number of salts containing carbanions have been determined by X-ray diffraction.Although a propeller-shaped anion is found in N,H,+[C(N0,),]-,'68" that in K+[C(NO,),] - has one NO group perpendicular to the plane of the rest of the anion.'68b The anions in Na+[C(CN],]-169a and K+[p-02NC6H4C(CN)2]-'696 are almost planar, but in Ca2+{C[C(CN),],}2- 6H,O each *C(CN) group is rotated out of the plane of the four central carbon atoms by 24°.169c The molecular structure of OCSe has been determined by microwave and that of C1,CSCl by gas-phase electron diffraction. l7'' ClSO N CC12 is- formed in the reaction between PCl and C1S02 NCO ; it may be fluorinated to FSO,-N:CCl with SbF,.17' The reaction between SCFCl and AgSCN at -25"c yields FC(S)NCS;17 FC(0)NCO was pre-pared from carbonyl fluoride and silicon tetraisocyanate or trimethylsilyl isocyanate.' 7 3 Reactions of C6F - CC* C6F have been studied ; it is prepared in good yield from C6F,MgBr and C212.174 Silicon.The chemistry of the SiF molecule has been reviewed,'75 and the heats of formation of the silicon dihalide molecules have been derived from studies of equilibria involving SiX,(g) SiX,(g) and Si(s) at high tempera-tures.' 7 6 Si,N has been detected by a mass spectroscopic method ; AH; (Si,N(g)) 93 5 k~al./mole.'~~ The dimensions of the HSiC1 and CH,SiCl molecules have been determined by microwave spectroscopy. 78a The crystal structure of BeSiN resembles that of wurtzite; all the atoms are tetrahedrally co-1 6 ' (a) R.N. Dixon G. Duxbury R. C. Mitchell and J. P. Simons Pro(,. Roy. Soc 1967. A ?W, 405; (b) A. P. Modica J . Chern. Phys. 1967 46 3663; (c) J. W. Coomber and E. Whittle. Trans. Faraduy SOC. 1967,63 1394. (a) B. Dickens Chem. Comm. 1967,246; (b) N. I. Golovina and L. 0. Atovmyan Zhur. strukt. Khim. 1967,8 307. 169 (a) P. Andersen B. Klewe and E. Thorn Acta Chem. Scand. 1967,21,1530; (b) R. L. Sass and C. Bugg Actu Cryst. 1967,23,282; (c) D. A. Bekoe P. K. Gantzel and K. N. Trueblood ibid. 1967, 22 657. (a) Y. Morino and C. Matsumura Bull. Chem. SOC. Japan 1967,40 1101; (b) N. V. Alekseev and F. K. Velichko Zhur. strukt. Khim. 1967,8,8. 17' H. W. Roesky and U. Biermann Angew. Chem. Internat. Edn.1967,6,882. 172 A. Haas and W. Klug Angew. Chem. Internat. Edn. 1967,6,940. 0. Glemser U. Biermann and M. Fild Chem. Ber. 1967 100 1082. J. M.-Birchall F. L. Bowden R. N. Haszeldine and A. B. P. Lever J . Chem. SOC. (A) 1967,747. H. Schaefer H. Bruderreck and B. Morcher 2. anorg. Chem. 1967 352 122; R. Teichmann and E. Wolf ibid. 1966 347 145; E. Wolf and C. Herbst ibid. p. 113; 2. Chem. 1967,7 34; E. Wolf, ibid. p. 283. "' J. C. Thompson and J. L. Margrave. Science. 1967 155- 669. K. F. Zmbov and J. L. Margrave J. Amer. Chem. SOC. 1967,89 2492. (a) M. Mitzlaff R. Holm and H. Hartmann Z . Naturforsch 1967 22b 1415; (b) P. Eckerlin, Z . rmory. Chem. 1967,353,223; (c) R. Marchand and J. Lang Compt. rend. 1967 C 264,969 254 A. J . Downs G. M. Sheldrick and J .J . Turner ordinated Si2N,0 is formed in a high-temperature reaction between SiO and ammonia.'78c The pyrolysis reactions of the cyclic compound (CH,),Si(CH,) provide evidence for high-temperature equilibria involving CH2:Si(CH,),;179" the synthesis of (CH2),SiX2 (X = H D F and C1) and the vibrational n.m.r. and mass spectra of these molecules have been des-cribed in The heats of hydrolysis of trimethylsilyl compounds have been used to measure Si-N -0 -S and -Br bond energies;18'" the value D(Me,Si-SiMe,) = 49 & 6 kcal./mole is obtained from the thermal decomposition of hexamethyldisilane,180b and the value D(H2As-SiH,) = 73 kcal./mole by mass spectroscopy.180c The p + d bonding energy has been predicted to be 16 kcal./mole for each Si-N bond in [SiH,),N by a SCF method.18' Electron diffraction has shown (SiH,),P and SiH,),As to have pyramidal heavy-atom skeletons,182o in contrast to planar (SiH,),N and despite the assignment of planar skeletal vibrational selection rules based on the absence of bands in the i.r.and Raman spectra.182b Si(NCO) is found to be bent at nitrogen by electron diffraction,'82c but it is difficult to determine the angle accurately because of the possibility of a low-frequency bending vibration and hence large 'shrinkage' effect. The dipole moments in [(C6H5)3Si]201LIZu and (Me3SiN)2C182e are 1.03 and 1 . 3 ~ respectively; the U.V. spectra of N-organo-silylketimines indicate the absence of Si-N multiple bonding. ' 82e The relative and acidities183b of silylamines and related com-pounds have been estimated using i.r.spectroscopy. Polysilanes have been reviewed'84 and the reactions of (Me,Si),Si- salts studied ;I8' preparations of NaSiPh and NaSiMePh have been described ;186" LiMEt (M = Si or Ge) are formed by the action of Li on the corresponding mercurials.186b Although LiPEt reacts with H,SiPEt to give LiH and H,Si(PEt,)&, (n = 1 or 2) it yields a bright red solution of LiSi(PEt,) with HSi(PEt,),. 186c Carb~silanes'~~" and cyclic organo-silicon compounds'87b have been reviewed. a-Silyl ketones may be conveniently prepared by (a) L. E. Gusel'nikov and M. C. Flowers Chem. Cornm. 1967,864; (b) J. Laane J. Amer. Chem. Soc. 1967,89 1144. (a) J. C. Baldwin M. F. Lappert J. B. Pedley and J. A. Treverton J . Chem. Soc. (A) 1967, 1980; (b) J. A.Connor R. N. Haszeldine G. J. Leigh and R. D. Sedgwick ibid. p. 768; (c) F. E. Saalfeld and M. V. McDowell Inorg. Chem. 1967 6 96. P. G. Perkins Chem. Comm. 1967,268. (a) B. Beagley A. G. Robiette and G. M. Sheldrick Chem. Comm. 1967,601 ; (b) G. Davidson, L. A. Woodward E. A. V. Ebsworth and G. M. Sheldrick Spectrochim. Acta 1967 A 23 2609; ( c ) K. E. Hjortaas Acta Chem. Scand. 1967 21 1381 ; (d) R. Varma A. G. MacDiarmid and J. G. Miller J . Organometallic Chem. 1967,9 77; (e) L-H. Chan and E. G. Rochow ibid. p. 231. (a) E. W. Abel D. A. Armitage and S. P. Tyfield J . Chem. Soc. (A) 1967 554; (b) J. Plazanet, F. Metras A. Marchand and J. Valade Bull. SOC. Chim. France 1967 1920. la4 G. Schott Fortschr. Chem. Forsch. 1967,9 60. '*' H. Gilman and C. L. Smith J . Organometallic Chem.1967 8 245; H. Gilman and R. L. Harrell ibid. 1967 9 67; H. Gilman and K. Shiina ibid. 1967,8 369. (a) F. W. G. Fearon and H. Gilman J . Organometallic Chem. 1967,9,403; (b) N. S. Vyazankin, G. A. Ruzuvaev E. N. Gladyshev and S. P. Korneva ibid. 1967,7 353; ( c ) G. Fritz and G . Becker, Angew. Chem. Internat. Edn. 1967,6,1078. (a) G. Fritz Angew. Chem. Intenat. Edn. 1967,6,677; (b) K. A. Andrianov and L. M. Khanan-ashvili Organometallic Chem. Rev. 1967,2 141 The Typical Elements 255 hydrolysis of the appropriate 2-substituted 1,3-dithianes (26) prepared from the 2-lithium-1,3-dithianes and organo-silyl halides.188 Me,SiNCNSiMe, and Me,SiCCSiMe have been prepared in good yields from Na2CN2 and CaC in fused salt mixtures;189a R,MCCM'R (M,M' = Si Ge Sn or Pb; R = Ph or Me) have been synthesised from Na2C,.189b (Me,Si),C:C:C(SiMe,), has been obtained in the reactions of pentafluorophenylsilyl compounds with lithium and trimethylsilyl chloride;'89c Me,Si- and Et,Ge- radicals have been added to double or triple bonds using the mercurials Hg(MR3),.lg0 Organo-silyl halides react with the appropriate alkali metal derivatives to give pentachlor~phenyl'~ la and ~yclopentadienyl~ lb silicon compounds plus the cyclopentadiene analogues (27) (M = Si or Ge; X Y = Me Ph or Cl); siloles and germoles (X = Y = H) are formed by the reduction of the corres-ponding chloro-compounds with LiA1H4 but do not react with butyl-lithium at low temperature to give sila- and germa-cyclopentadienide anions.lgl' N-Bromosuccinimide reacts with hexamethyldisilane to give trimethylsilyl-bromide and N-trimethylsilylsuccinimide ;' silyl iodide reacts with piperi-dine and pyrrolidine to give the appropriate N-silyl derivatives which form 1 1 adducts with BMe and SiH,I and a 2 1 adduct with HCl at -88"c, formulated as a salt of HCl,- which liberates silyl chloride on warming to room ternperat~re.'~,~ Me,SiNLiBu' reacts with Me,SiCI in Et,O to give the expected (Me,Si),NBu' but in THF the product is Me,SiCH,SiMe,NHBu'.' A. G. Brook J. M. Duff P. F. Jones and N. R. Davis J . Amer. Chem. Soc. 1967 89 431; E. J. Corey D. Seebach and R. Freedman ibid. 1967,89,434. (a) J. Stenzel and W. Sundermeyer Chem. Ber. 1967 100 3368; (b) W. Findeiss W. E. Davidsohn and M. C. Henry J . Organometallic Chem.1967 9 435; (c) F. W. G. Fearon and H. Gilman Chem. Comm. 1967 86. K. Kiihlein W. P. Neumann and H. P. Becker Angew. Chem. Internat. Edn. 1967,6 876. 19' (a) H. Gilman and S-Y. Sim J . Organometallic Chem. 1967 7 249; P. J. Morris F. W. G. Fearon and H. Gilman ibid. 1967,9,427; (b) I. M. Shologan and M. K. Romantsevich Zhwr. obshchei Khim. 1966 36 1846; (c) M. D. Curtis J . Amer. Chem. Soc. 1967 89 4241. 192 (a) H. Sakurai A. Hosomi J. Nakajima and M. Kumada Bull. Chem. Soc. Japan 1966 39, 2263; (b) B. J. Aylett and J. Emsley J . Chem. SOC. (A) 1967 1918. (a) R. P. Bush N. C. Lloyd and C. A. Pearce Chem. Comm. 1967 1270; (b) N. Wiberg and F. Raschig J . Organometallic Chem. 1967 10 15; N. Wiberg F. Raschig and K. H. Schmid ibid., p. 29; ( c ) N. Wiberg and W. C.Joo Z . Naturforsch. 1966,21b 1234; (d) N. Wiberg and K. H. Schmid, Z . Naturforsch. 1966,21b 1107 256 A. J . Downs G. M. Sheldrick and J . .I. Turner The preparation and reactions of N-halogeno-silylamines have been studied in detail ;lg3' although (Me,Si),NNa reacts with phenyl diazonium chloride to give (Me,Si),NNNC,H (stable at - 150),lg3' attempts to prepare (R,Si),NNO were not successful.193d The reactions of Me,N(SiH,), (n = 0, 1 or 2) with C02 CS, and COS have been studied by n.m.r.,19,' and silyl formate acetate and trifluoracetate prepared from N(SiH,) and the appro-priate anhydrous acids. 194h A variety of cyclosilazanes have been made, including those with four-membered Si,N rings ; the usual methods involve redistribution reactions of Si-N and Si-Cl bonds or lithium organo-silylamides.19' The low-temperature reaction between SiCl and ammonia yields (Cl,Si),NH (Cl,SiNH) and polymer;'96" the mixed Si Ge and Sn derivatives Me,SiNMeSiMe,N(GeMe,)SnMe, Et,SiN(GeMe,)SnMe, and (Et,SiNGeMe,) were prepared using lithium organo-silylamides. ' 96b Several organo-silylhydrazines have been prepared ;I9 '" (28) and (29) are in tautomeric equilibrium at room temperature as are 1,l- and 1,2-bis(trimethylsilyl)hydra-zines. ' 97b Me,SiN PR3 and its germanium and tin analogues have been prepared from R,P:NLi and Me3MC1,198" and Me,MCH:PR and (Me,M),C:PR, (M = Si Ge or Sn) by several methods.'98b Organo-siloxy-derivatives of metals have been reviewed,' and the isoelectronic series of organo-silicon compounds having the cubane structure have been discussed.'99b The Si,02N ring in crystalline (30) has a distorted 'boat' conformation.' 99c Cyclic siloxanes may be titrated potentiometrically with Bu,N+OH- in pyridine because of the formation of cyclic H-bonded anions.' 99d Organo-sulphur derivatives of Si, Ge Sn and Pb have been extensively reviewed ;,O0 bis(triarylsily1)poly-sulphides are formed in the reactions between R,SiSNa and I, R,SiCl or S,Cl ; similarly R,SiONa with S,C12 yields R,SiO-S,-OSiR (R = ary1).201" Silyl iodide reacts with Li,Te to give (H3Si),Te which has been studied spectroscopically.20 '' Salts of SiF have been prepared and evidence The action oftrimethylphosphine on Me,Si(N,) gives Me,Si(N PMe,), 194 (a) E. A. V. Ebsworth and J. C. Thompson J . Chem. SOC. (A) 1967,69; (b) E.A. V. Ebsworth, G. Rocktaschel and J. C. Thompson ibid. p. 362. 19' R. P. Bush N. C. Lloyd and C. A. Pearce Chem. Comm. 1967 1269; J. Silbiger J. Fuchs, and N. Gesundheit Inorg. Chem. 1967,6,399; U. Wannagat E. Bogusch and F. Hofler J . Organo-metallic Chem. 1967 7 203; U. Wannagat P. Schmidt and M. Schulze Angew. Chem. Internat. Edn. 1967,6 447; U. Wannagat and 0. Brandstltter Monatsh. 1966,97 1352. 196 (a) U. Wannagat P. Schmidt and M. Schulze Angew. Chem. Internat. Edn. 1967,6,446; (b) 0. Scherer and D. Biller ibid. p. 446; Z . Naturforsch. 1967,22b 1079. 19' (a) F. Hofler and U. Wannagat Monatsh. 1966,97 1598; (b) C. G. Pitt and K. R. Skillern, h o g . Chem. 1967,6,865. 19* (a) H. Schmidbaur and G. Jonas Chem. Ber. 1967 100 1120; (b) H. Schmidbaur and W.Tronich Chem. Ber. 1967,100,1032. 199 (a) F. Schindler and H. Schmidbaur Angew. Chem. Internat. Edn. 1967,6,683; D. C . Bradley, Co-ordination Chem. Rev. 1967 2 299; (b) H. Schmidbaur Allg. prakt. Chem. 1967 18 138; (c) W. Fink and P. J. Wheatley J . Chem. SOC. (A) 1967,1517; (d) R. H. Baney afid F. S. Atkari J . Organo-metallic Chem. 1967,9 183. zoo E. W. Abel and D. A. Armitage Adu. Organometallic Chem. 1967 5 1. '01 (a) B. Martel and N. Duffant Compt. rend. 1967 C 264 452; F. Feher and H. Goller, 2. Naturforsch. 1967,22b pp. 1224,1225; (b) H. Burger and U. Goetze Znorg. Nuclear Chem. Letters, 1967,3 549 The Typical Elements 257 is presented for GeF; ;202 a ten-membered nearly planar ring of alternating silicon and nitrogen atoms is found in the crystal structure of H3SiNMe2; each silicon atom is five-co-ordinate with two long (1.95 A) Si-N bonds.203u A five-co-ordinate silicon cation is suggested by the i.r.spectra of the 1 :2 and 1 1 adducts of H,SiMn(CO) with trimethylamine and 2,2'-bipyridyl res-p e ~ t i v e l y . ~ ' ~ ~ There have been a number of studies of adducts of organo-silyl halides with mono- and bi-dentate bases; evidence was found for ionic structures for some of the adducts.204Q The heats of formation of the pyridine and isoquinoline adducts of the type MX4,2L (M = Si Ge or Sn; X = F C1, or Br) have been measured.204b Germanium. Potassium germyl and alkylgermyls have been obtained by the action of the corresponding hydrides on KOH in 1,2-dimethoxyethane20su or potassium in hexamethylphosphorylamide ;205b a byproduct Ge(NH),,xNH, is formed when KGeH is prepared from potassium and germane in liquid ammonia.205c The molecular dimensions of H,GeCN206" and H,GeSiH,206b have been obtained by microwave spectroscopy; the i.r.and Raman spectra of H,GeNCS show that the molecule has a bent heavy-atom skeleton.206c The relative Lewis base strengths of some simple methyl silyl and germyl oxides and sulphides have been compared by an i.r. method using methanol and phenol as reference acids; H,GeSCH was prepared by the action of H,GeCl on solid NaSCH,.207 The equilibrium constants have been obtained for the exchange reactions of silyl or germyl halides with hydrogen halides :208a GeH,I and GeH212 may be conveniently prepared from the corresponding chlorides and HI,208b and (H,Ge),P has been obtained from (H,Si),P and H,GeBr.208c A non-random distribution of products has been found in the redistribution reactions of H,CGeX (X = Cl Br I OMe or SMe).208d (Me,Ge),Hg may be prepared by the reaction of Me,GeBr with sodium ' 0 2 K.Behrends and G. Kiel Naturwiss. 1967 54 537; H. C. Clark and K. R. Dixon Chem. Comm. 1967,717; H. C. Clark P. W. R. Cofield K. R. Dixon and J. A. Ibers J. Amer. Chem. SOC., 1967,89,3360. '03 (a) R. Rudman W. C. Hamilton S. Novick and T. D. Goldfarb J. Amer. Chem. SOC. 1967, 89 5157; (b) B. J. Aylett and J. M. Campbell Chem. Comm. 1967 159. '04 (a) H. J. Campbell-Ferguson and E. A. V. Ebsworth J . Chem. SOC. (A) 1967 705; T. Tanaka, G. Matsubayashi and A. Shimizu Inorg. Nuclear Chem. Letters 1967 3 275; U.Wannagat, K. Hensen and P. Petesch Monatsh. 1967,98 pp. 1407 1423; U. Wannagat K. Hensen P. Petesch, and F. Vielberg ibid. p. 1415; ( b ) J. M. Miller and M. Onyszchuk J. Chem. Soc. (A) 1967 1132. '05 (a) W. L. Jolly J. Chem. Educ. 1967,44,304; (b) S. Cradock G. A. Gibbon and C. H. van Dyke, Inorg. Chem. 1967 6 1751; E. J. Bulten and J. G. Noltes Tetrahedron Letters 1967 1443; (c) D. S. Rustad and W. L. Jolly Inorg. Chem. 1967,6 1986. '06 (a) R. Varma and K. S. Buckton J. Chem. Phys. 1967,46 1565; (b) A. P. Cox and R. Varma, J. Chem. Phys. 1967,46,2007; (c) G. Davidson L. A. Woodward K. M. Mackay and P. Robinson, Spectrochim. Acta (A) 1967,23,2383. '07 J. T. Wang and C. H. van Dyke Inorg. Chem. 1967,6,1741; Chem. Comm. 1967 pp. 612,928; G. A.Gibbon J. T. Wang and C. H. van Dyke Inorg. Chem. 1967,6 1989. ' 0 8 (a) S. Cradock and E. A. V. Ebsworth J . Chem. SOC. (A) 1967 1226; (b) S . Cradock and E. A. V. Ebsworth ibid. p. 12; (c) S. Cradock E. A. V. Ebsworth G. Davidson and L. A. Woodword, ibid. p. 1229; (d) K. Moedritzer and J. R. Van Wazer J. Inorg. Nuclear Chem. 1967 29 1571 258 A. J . Downs G. M . Sheldrick and J . J . Turner amalgam or by the action of Me,GeH on Et,Hg ;,Oga hydrogenolytic fission of Ge-N or Sn-N bonds with organo-tin and -germanium hydrides has led to the synthesis of a variety of linear and branched compounds with Ge-Sn bonds.209b GeH,Br reacts with LiAl(PH,) in ether to give a good yield of H3GePH ;209c organo-germyl carboxylates sulphates selenites and selenates are obtained by silver salt reactions.209d The cyclic (Cl,GeNMe) has been obtained from GeC1 and H3CNH2 ;,lea in the presence of trimethylamine, H2S reacts with MeGeBr to yield (MeGe)& shown by crystallography to be isostructural with ( MeSi),S,.,l Ob The Russian work on the crystallography and chemistry of the Ge heterocyclic compounds (31) has been summarised; there is no evidence for interaction between the 4d orbitals on Ge and the 71-bonding orbitals although the rings are planar211 (X = C1 Br I OH Me, Et Bu or Ph; R = H or Ph).H e x 2 N et Ph2Si' SiPh, I I x2 e )3( R R 0%€4?2 (30) (31) Tin. In orthorhombic SnF the tin atoms are in an approximately trigonal pyramidal environment with two short (2.15 A) and one longer (2.45 A) Sn-F distances.212" SnCl is dimerised to the extent of 13% in the vapour phase at ~ O O " C .~ ' 2b The SnF,-M"F phase diagrams have been studied and i.r. and Mossbauer evidence presented for the presence of the SnF; ion in M(SnF,) (M = Sr Ba or Pb) and similar compounds; Sr(Sn,F,) and Ba(Sn,F,) were prepared.,12' NaSn,F crystallises from hot aqueous hydrofluoric acid as hexagonal prisms.212d The Raman spectra of molten and crystalline SnCl have been interpreted in terms of chain polymers of the type (SnCl,) involving three-co-ordinate tin ; the spectra for increasing concentrations of KCl in the melt were interpreted in terms of gradual de-polymerisation with ultimate formation of pyramidal SnCl; ions. lZe Mossbauer spectra of Sn"C1,2- and Sn*VC1,2 - absorbed on anion exchange resins were interpreted in terms of C, and octahedral symmetry re~pectively.~' ' 0 9 (a) C.Eaborn W. A. Dutton F. Glockling and K. A. Hooton J . Organometallic Chem. 1967, 9 175; (b) H. M. J. C. Creemers and J. G. Noltes J . Organometallic Chem. 1967 7 237; (c) D. C. Wingleth and A. D. Norman Chem. Comm. 1967,1218 ; (6) T. N. Srivastava and S. K. Tandon Z . anorg. Chem. 1967,353,87. 'Io (a) W. Eisenhuth and J. R. Van Wazer Inorg. Nuclear Chem. Letters 1967 3 359; (b) K. Moedritzer Inorg. Chem. 1967,6 1248. 211 M. E. Vol'pin V. G. Dulova Y. T. Struchkov N. K. Bokiy and D. N. Kursanov J . Organo-metallic Chem. 1967,8 87. 212 (a) J. D. Donaldson and R. Oteng Inorg. Nuclear Chem. Letters 1967,3,163 ; (6) N. V. Karpenko and G. I. Novikov Vestn. Leningrad Unio. 22 Ser. Fiz. Khim.1967 1 72; (c) J. D. Donaldson and B. J. Senior J . Chem. SOC. (A) 1967 1821 ; (d) J. C. Muhler G. K. Stookey and C. W. Beck J . Dental Res. 1967,46 380; (e) J. H. R. Clarke and C. Solomons J . Chem. Phys. 1967,47 1823. 213 V. I. Baranovskii G. M. Gorodinskii L. M. Krizhanskii B. I. Rogozev and S. B. Tomilov, Radiokhimiya 1967,8 365 The Typical Elements 259 Electron diffraction studies of (n-C,H,),Sn and (n-C,H,),Pb show that in both molecules the planes of the cyclopentadiene rings are tilted with respect to one another.214 Ti@) alkoxides are formed from SnCl and alcohols in the presence of trimethylamine.21s The existence of Sn,S has been confirmed and the crystal structure determined ;,I6 in the crystals of MSn(OH) (M = Ca or Zn) the tin atoms are surrounded by irregular octahedra of oxygen Sn03H and Sn,0,H2 have been identified in a study of the thermal decomposition of SnIV hydroxides by thermogravimetric analysis, electron diffraction and broad line n .~ . r . ' ~ ~ Mossbauer spectra show that discrete SnFi- octahedra are not present in SnF,,2BrF,.217c The stability constants of the methyltin(1v) fluoride complexes have been determined by various Redistribution exchange rates have been determined by n.m.r. in alkyltin halides2I9" and a m i n e ~ . ~ ' ~ ' The five-co-ordinate tin com-plexes Me,SnLl B(C,H,) have been prepared and characterised (L = Me,SO HCONMe, MeCONMe, or H20),220u and' the insoluble (poly-meric ?) forms of trimethyltin formate and acetate converted into soluble (cyclic ?) forms by heating in a sealed tube with cyclohexane.220b There have been a number of spectroscopic studies of six-co-ordinate tin(rv) complexes.221 The dipole moment of cis-bis(acetylacetonato)tin(rv) dichloride does not vary with temperature""" but the n.m.r.resonances due to two methyl groups collapse to a single line;222b this has been interpreted in terms of a cis-cis enantiomeric equilibrium. The co-ordination of the tin atom in crystalline dimethyltin bis(8-hydroxyquinolinate) is a very distorted octahedron with cis-methyl groups.222c The complex (Me,SbS),SnMe,Cl is monomeric in toluene but dissociates in chloroform; Me,SbCl and (Me,SnS) may be present in the R,SnY (Y = 0 or S) give (ClR,Sn),Y and ClR,SnYSnR'Cl with R,SnCl and R'SnCl respectively.223b The reaction between R,Sn(OMe) and R,SnX yields R,Sn(OMe)X exothermally and '14 A.Almenningen A. Haarland and T. Motzfeldt J. Organometallic Chem.,,l967,7 97. '15 J. S. Morrison and H. M. Haendler J. Inorg. Nuclear Chem. 1967,29,393. '16 D. Mootz and H. Puhl Acta Cryst. 1967 23 471. '" (a) C. Cohen-Addad Bull. Soc.fianc. Mineral. Cryst. 1967 90 32; (b) E. W. Giesekke H. S. Gutowsky P. Kirkov and H. A. Laitinen Inorg. Chem. 1967,6 1294; (c) V. F. Shukhoverkov and B. E. Dzevitskii Doklady Chem. 1966 170 983 "* A. Cassol Gazzetta 1966 % 1764; A. Cassol and L. Magon ibid. pp. 1724 1752; A. Cassol and R. Portanova ibid. p. 1734; A. Cassol L. Magon and R. Barbieri Inorg. Nuclear Chem. Letters, 1967 3 25. '19 (a) E. V. Van den Berghe G. P. Van der Kelen and Z. Eckhaut Bull. SOC. chim. belges 1967, 76,79; (b) E.W. Randall C. H. Yoder and J. J. Zuckerman J. Amer. Chem. SOC. 1967,89 3438. ''O (a) V. G. Kumar Das and W. Kitching J. Organometallic Chem. 1967 10 59; (b) P. B. Simons and W. A. G. Graham J. Organometallic Chem. 1967 8 479. '" J. L. Wardell J. Organometallic Chem. 1967,9 89; H. C. Clark and R. C. Goel ibid. 1967 7, 263; R. C. Poller and D. L. B. Toley J. Chem. SOC. (A) 1967,1578; W. H. Nelson Inorg. Chem. 1967, 6 1509; M. F. Farona and J. G. Grasselli ibid. p. 1675. "' (a) V. Doron and C. Fischer Inorg. Chem. 1967,6 1917; (b) J. W. Faller and A. Davison ibid., p. 182; (c) E. 0. Schlemper ibid. p. 2012. ''3 (a) M. Shindo and R. Okawara Inorg. Nuclear Chem. Letters 1967 3 75; (b) A. G. Davies and P. G. Hamson J. Organometallic Chem. 1967,7 P13; 1967,8 P19; (c) A.G. Davies and P. G. Harrison J. Chem. SOC. (C) 1967,298 260 A. J . Downs G. M . Sheldrick and J . J . Turner apparently quantitatively (X = F C1 Br I OCOR’ NCS or OS0,R’); equilibria involving methoxy-bridged dimers are suggested.223c Et,SnSeGeEt,, Et,GeYH (Et,Ge),Y and (Et,Sn),Y (Y = S or Se) have been obtained by reactions of sulphur and selenium with triethyl-tin and germanium hy-drides ;224u dihalogeno-carbenes have been inserted into the Sn-Sn bond in hexamethyldi~tannane.~,~~ The addition of acrylonitrile to a Sn-H bond followed by cleaving a Sn-Ph bond with bromine served to synthesise Br,,Sn(CH,*CH,*CN), (n = 2 or 3).224‘ Addition of Bu,SnCl to the product of the reaction between CaCN and CS gives (32);225u (33) have also been prepared (X = H or CN).,,’’ Trialkyltin azides react with PR; to give R,SnN PR; ;226 triaryltin iodides give triaryltin isocyanates with Pb(NCO) ; the i.r.spectra indicate the presence of Sn-N bonds.227 RiMOPR (M = Si, Ge Sn) have been prepared by the reaction of R,POK or R2PH0 with R;MOPR2228a or by the reaction of R,PCl with R;SnOLi (M = Sn);228b R,SnPR (R = Ph) give R,SnSP(S)R and R,SnOP(O)R with sulphur and oxidizing agents respectively.228b The alkali-metal derivatives R,Sn-M+ have proved useful in the synthesis of Me,SnSiMe,,229u organo-stannyl-~tibines~,~’ and -acetylenes ;229c silyl- and germyl-stannane (stable below -80”) have been prepared by the elegant reaction sequence (34).229d R2 (32 (33) Ph,SiK + CISnPh,TzPh,SiSnPh, Reflux with acetic anhydride LiAlH liquid HCI \ H,SiSnH,dCl,SiSnCl - .(AcO),SiSn(OAc), EtZO (34) Lead.CsPbBr is isostructural with CsPbI ; the crystal structure involves distorted PbBr octahedra linking to form (PbBr -), chains.230 Solvolysis of 224 (a) N. S. Vyazakin M. N. Bochkarev and L. P. Sanina Zhur. obshchei Khim. 1966 36 1961 ; (b) D. Seyferth and F. M. Armbrecht J . Amer. Chem SOC. 1967,89,2790; (c) G. H. Reifenberg and W. J. Considine J . Organometallic Chem. 1967,9 505. 22s (a) W. Stamm and C. C. Greco 1967 U.S. Patent 3,316,284; (h) E. W. Abel and C. R. Jenkins, J . Chem. SOC. (A) 1967,1344. 226 W. L. Lehn Znorg. Chem. 1967 6 1061; J. Lorberth H. Krapf and H. Noth Chem Ber., 1967,100,3511. 227 T. N. Srivastava and S. N. Bhattacharya J . Znorg. Nuclear Chem. 1967,29 1873.228 ( a ) K. Issleib and B. Walther Angew. Chem. Znternat. Edn. 1967 6 88; (b) H. Schumann, P. Jutzi A. Roth P. Schwabe and E. Schauer J . Organometallic Chem. 1967 10 71. 229 (a) H. Schumann and S. Ronecker Z . Naturforsch. 1967 22b 452; (b) H. Schumann, T. Oestermann and M. Schmidt J . Organometallic Chem. 1967,8,105 ; (c) V. S. Zavgorodnii and A. A. Petrov Zhur. obshchei Khim. 1966,36,1480; (d) E. Wiberg E. Amberger and H. Combensi Z . anorg. Chem. 1967,351,164. 230 A. Marstrander and C. Knakkergard Moeller Kgl. dan. Videnskab. Selskab Mat.-Fys. Medd., 1966,35 1 The Typicul Elements 26 1 PbPh4 by KNH2 in liquid ammonia gives K[Pb(NH,),] benzene and nitrogen.231 Lead(1v) acetate gives the isomorphous series of salts M1PbWIO6 in aqueous HI04 and the isomorphous series M:Pb'V(I03)6 in aqueous H103.232 Adducts are formed between PbC14 and pyridine 2,2'-bipyridyl, 1,lO-phenanthroline quinoline triphenylphosphine and triphenylphosphine oxide ; ethers yield very unstable a d d ~ c t s .~ ~ ~ " Sulphur dioxide and trioxide react with PbR4 (R = Me or Et) to give R,Pb(0,SR),-,233b and RnPb(S03R)4-n233c (n = 2 or 3) respectively. Group VdVitrogen. The N3 molecule has been obtained in molecular beams,234a and the ions N; and NZ detected by mass spectroscopy.234b Stable crystalline tetra-alkylammonium amalgams have been prepared by electrolysis of tetra-alkylammonium halides in non-aqueous solvents.235 pK Values have been determined potentiometrically in liquid ammonia ; the ionic product of liquid ammonia at -60°C is found to be 10-32.236a The primary solvation numbers of Mg2+ and A13+ in liquid ammonia have been shown to be 5.0 k 0.2236b and 6.03 f 0-45236c respectively by n.m.r.The NO3 radical has been identified by e.s.r. in electron-irradiated NaNO crystals.237a The equilibrium constant for the dissociation of N203 has been redetermined as a function of temperature ;237b the i.r. spectrum of the hyponitrite ion has been reassigned using 15N substitution the ion probably having CZh symmetry in the solid.237c Evidence has been found for the N2074- ion in fused salts,237d and a convenient preparation of ClN03 from ClF and HNO de~cribed.~," A planar centro-symmetric H(N03); ion has been found in the crystal structure of the tetra-phenylarsonium salt; there is a short and probably symmetrical 0-H-0 bond (2.45 A);238a on the other hand in truns-[RhC12py4]+H(N0,)~ the hydrogen atom appears to lie inside a tetrahedron of four oxygen atoms.238b The hydrogen bonding in NH30H+C1- and ferroelectric Li+N2Hi SO:-has been studied by neutron diffra~tion.~~*'*~ The i.r.spectra of gas solid, and matrix-isolated HNCS and DNCS have been interpreted in terms of strong hydrogen-bonding in the solid The reaction between F atoms and 231 0. Schmitz-Du Mont and W. Jansen Z . anorg. Chem. 1967 349 189. 232 R. Frydrych Chem. Ber. 1967,100 pp. 1340,3588. 233 (a) H. Clees and F. Huber Z . anorg. Chem. 1967,350 35; 1967 352 200; (b) R. Gelius ibid., 234 (a) F. M. Devienne J. C. Roustan and J. J. Belliardo Compt. rend. 1967 264 B 1454; (b) 235 J. D. Littlehailes and B.J. Woodhall Chem. Comm. 1967,665. 236 (a) M. Herlem Bull. SOC. chim. France 1967,1687; (b) T . J. Swift and H. H. Lo J . Amer. Chem. SOC. 1967,89 3988; (c) H. H. Glaeser H. W. Dodgen and J. P. Hunt J . Amer. Chem. SOC. 1967,89, 3065. 237 (a) R. Adde Compt. rend. 1967 264 C 1905; ( b ) M. Sole and V. Pour Coll. Czech. Chem. Comm. 1967 32 3031 ; (c) G. E. McGraw D. L. Bernitt and I. C. Hisatsune Spectrochim. Acta (A), 1967 23,25; (d) A. M. Shams El Din and A. A. El Hosary J . Inorg. Nuclear Chem. 1966 28 3043; (e) C. J. Schack Inorg. Chem. 1967,6 1938. 238 (a) B. D. Faithful and S. C. Wallwork Chem Comm. 1967 1211 ; (b) G. C. Robinson R. Mason, and D. R. Russell ibid. p. 62; (c) V. M. Padmanabhan H. G. Smith and S. W. Peterson Acra Cryst., 1967,22,928; (d) V.M. Padmanabhan and R. Balasubramanian ibid. p. 532; (e) J. R. Durig and D. W. Wertz J . Chem. Phys. 1967 46 3069. 1967 349 22; (c) R. Gelius and R. Muller ibid. 1967 351,42. R. K. Asundi G. J. Schulz and P. J. Chantry J . Chem. Phys. 1967,47 1584 262 A. J . Downs G. M. Sheldrick and J . J . Turner NH in an argon matrix at 1 4 " ~ gives HNF.,,'" U.V. spectra indicate that NH,Br dissociatesintoanequilibriummixtureofNHBr, NH,Br and NH inether.239b The nitrogen fluorides have been reviewed ;240 two independent determinations of the heat of formation of NF are in good agreement.241 Raman and "F n.m.r. spectra confirm that the NF4+ cation in NF4AsF6 and NF4SbF6 is tetrahedral.242" The molecular structures of NF, N2F4,242b and cis- and trans-N,F 242c have been determined by gas-phase electron diffraction ; rotational analysis242d of the i.r.spectrum of trans-N,F is consistent with this. The thermochemistry of the dissociation of N2F4243a and the cis-trans isomerisation of N,F 243b have been investigated ; N2F4 forms a 1 2 adduct with AsF at - 78" which dissociates to give a 1 1 adduct at room temperature, and evidence is presented for the formulation of the latter as N2F3 +ASF6-.243c AH;[NF,Cl(g)] = 3.2 k 2.9 kcal./mole leading to an estimate of 35.3 kcal./mole for the N-Cl bond energy.244 Convenient preparations of N,F, and HNF have been described.245 The i.r. spectrum of F,NO is consistent with C3" and the molecular dimensions of H,CNF have been determined from the microwave spectrum.246b The action of NF and N2F4 as fluorinating agents has been inve~tigated,,~~" the heats of formation of some NF2- derivatives have been determined calorimetrically,247b and adduct formation between NF,CFO and CsF or KF used in the preparation of NF,- derivatives ;247c (CF,),NO- derivatives have been prepared via the KF or CsF adducts of (CF,)2NOH.247d Fluorina-tion of CF,NO with F,-AgF yields (CF3),NOCF,.247e The (CCl,),NO radical has been identified by e .~ . r . ~ ~ The cyclic structure of F,CN has been confirmed by gas-phase electron diffraction,249" and the vibrational spectra of (F,CSNCO) interpreted in terms of a four-membered carbon-nitrogen ring with trans-SCF sub~tituents.~~'~ The preparation and reactions of the 2 3 9 (a) M. E. Jacox and D. E. Milligan J. Chem. Phys. 1967,46 184; (b) J.Jander and C. Lafrenz, 240 J. K. Ruff Chem. Rev. 1967,67,665. 241 L. C. Walker J . Phys. Chem. 1967,71 361 ; G. C. Sinke ibid. p. 359. 242 (a) W. E. Tolberg R. T. Rewick R. S. Stringham and M. E. Hill Inorg. Chem. 1967,6 1156; K. 0. Christe J. P. Guertin A. E. Pavlath and W. Sawodny ibid. p. 533. (b) R. K. Bohn and S. H. Bauer ibid. p. 304; (c) R. K. Bohn and S . H. Bauer ibid. p. 309; (d) S-T. King and J. Overend Spectrochim. Acta (A) 1967,23,2875. 243 (a) G. von Ellenrieder E. Castellano and H. J. Schumacher 2. phys. Chem. 1967 55 144; (b) A. V. Pankratov and 0. M. Sokolov Zhur. neorg. Khim. 1966 11 1761; (c) A. R. Young and D. Moy Inorg. Chem. 1967,6 178. 244 A. N. Zercheninov V. I. Chesnokov and A. V. Pankratov Zhur.$z. Khim. 1966,40 2101. 245 D.L. Klopotek and B. G. Hobrock Inorg. Chem. 1967,6 1750. 246 (a) E. C. Curtis D. Pilipovich and W. H. Moberly J. Chem. Phys. 1967,46,2904; (b) L. Pierce, R. G. Hayes and J. F. Beecher ibid. p. 4352. 247 (a) U. Biermann 0. Glemser and J. Knaak Chem. Eer. 1967,100 3789; (b) G. C. Sinke C. J. Thompson R. E. Jostad L. C. Walker A. C. Swanson and D. R. Stull J. Chem. Phys. 1967 47, 1852; (c) G. W. Fraser and J. M. Shreeve Inorg. Chem. 1967,6,1711; (d) D. P. Babb and J. M. Shreeve ibid. p. 351; (e) J. M.Shreeve and D. P. Babb J. Inorg. Nuclear Chem. 1967 29 1815. Z . anory. Chem. 1967,349 57. 14' H. Sutcliffe and H. W. Wardale J. Amer. Chem. SOC. 1967,89,5487. 249 (a) J. L. Hencher and S. H. Bauer J . Amer. Chem. SOC. 1967 89 5527; (b) A. J. Downs and A. Haas Spectrochim.Acta (A) 1967,23 1023 The Typical Elements 263 halogen azides have been reviewed.250 Four-membered Sb-N and Sn-N rings have been postulated in (SbCl,N,) and (C12Sn(N3)2)n,251 similar to the six-membered rings in (Me,AlN,) ','' and (Et2GaN3)3;150d on the other hand dialkyl boron azides possess appreciable dipole moments and are mono-meric."' Salts of the cation [N3C(NH2),]+ can be obtained by the action of Me,SiN on ClC(NH,)i salts or HN0,-HCl on (H,N),C:NHNH2+ HC03-.252 Addition of SOCl to (Me,SiN),C gives NC N S :O;253a an aqueous mixture of potassium hydroxide tetraphenylphosphonium chloride and NSF yields the tetraphenylphosphonium salt of the anion NSF,O- 253b Phosphorus. Reviews have appeared on the stereochemistry of optically active phosphorus phosphorus-boron and phosphorus-nitrogen compounds.256 The P-Cl radical has been detected in the isothermal flash photolysis of PCI vapour ;257a the low-pressure pyrolysis of P2H4 has been shown to occur by a surface-catalysed mechanism; the only volatile products detected were PH, P,H, and P4.257b Lip has been prepared by heating Li,P with red phosphorus.257' The P-H bond length in PH,I has been found to be 1-414 A by neutron diffraction,258a in agreement with the broad-line n.m.r.determination. The PHf ion has been identified by n.m.r. in the strong acids H,O BF and CH,OH BF, and the protonation of H,P(O)OH and HP(O)(OH) studied in sulphuric Methylphosphine has been obtained by reduction of Cl,PCH with CiAlH4 in ether; it reacts with BH,CO to give CH,PH2*BH,.259a CF,EH and (CF,),EH (E = P As) have been made by reducing the corresponding iodides with HI and mer-cury ;"" the unstable cyclic (CH,),PH has been chara~terised.~~'' Cyclo-polyphosphines have been the subject of two reviews ;260 cyclopolyphosphine rings have been cleaved by bromine261a or methylphosphines,261b but sulphur reacts with (C,H,P) to give a 3-phosphorus ring-compound (C6H,PS),.26'c N.m.r.provides evidence for 'pseudo rotation' in (PCF,) on 2so K. Dehnicke Angew. Chem. Internat. Edn. 1967,6,240. 2s1 U. Miiller and K. Dehnicke Z . anorg. Chem. 1967 350 113; N. Wiberg and K. H. Schmid, 2s2 A. Schmidt Chem. Ber. 1967,100,3725. 2s3 (a) 0. J. Scherer and R. Schmitt Angew. Chem. Internat. Edn. 1967,6 701 ; (b) H. W. Roesky, 254 J. Michalski Bull. SOC. chim.France 1967 1109. 255 G. W. Parshall 'The Chemistry of Boron and its Compounds' ed. E. L. Muetterties Wiley, 2s6 E. Fluck Topics Phosphorus Chem. 1967,4,291. "' (a) N. Basco and K. K. Yee Chem. Comm. 1967 1146; (b) T. P. Eehlner J . Amer. Chem. SOC., 1967,89,6477; (c) K. Langer and R. Juza Naturwiss. 1967,54,225. 2s8 (a) A. Sequeira and W. C. Hamilton J . Chem. Phys. 1967,47,1818; (b) G. M. Sheldrick Trans. Faruday SOC. 1967,63 1077. 2s9 (a) L. J. Malone and R. W. Parry Inorg. Chem. 1967,6,176; (b) R. G. Cave11 and R. C. Dobbie, J . Chem. SOC. (A) 1967 1308; (c) R. I. Wagner L. D. Freeman H. Goldwhite and D. G. Rowsell, J . Amer. Chem. SOC. 1967,89 1102. 260 L. Maier Fortschr. Chem. Forsch. 1967 8 1 ; A. H. Cowley and R. P. Pinnell Topics Phos-phorus Chem. 1967,4 1.261 (a) M. Baudler 0. Gehlen K. Kipker and P. Backes Z . Naturforsch. 1967 22b 1354; (b) A. H. Cowley J . Amer. Chem. SOC. 1967,89 5990; (c) M. Baudler K. Kipker and H. W. Valpertz, Naturwiss. 1967,54,43; (dj E. J. Wells H. P. K. Lee and L. K. Peterson Chem. Comm. 1967 894. Chem. Ber. 1967,100 pp. 741,748. 0. Glemser A. Hoff and W. Koch Inorg. Nuclear Chem. Letters 1967,3 39. New York 1967,617 264 A. J . Downs G. M. Sheldrick and J . J . Turner Pentafluorophenyl di- and cyclopenta-phosphines have been prepared from pentafluorophenyl phosphorus halides ; the reaction between PhPCl and C6F5PH2 gives (C6F,P) in 94 % yield.262 Addition of H,S2 in CS to RPC1, in ether gives (RPS,) ;2634 (C6H5PS2) adds PBu to give C,H,PS,PBU,.~~~~ R4P2 reacts with R'NCS to produce R,PC(S) NHR'.263c Red phosphorus is reduced by sodium in liquid ammonia to give products formulated as (PNa),, Na,PPNa, and PNa, used in situ to prepare mono- and di-phosphine~,~~~" but by analogy with the corresponding reaction of white phosphorus the reduction products may be of the type (Na2P,H + 2NaNH,) etc.KPHPh, MPPh, and MAsPh (M = Na K Rb or Cs) are 1 1 electrolytes in dimethyl-sulphoxide. 264b The chemistry of the phosphorus halides has been reviewed.265 Fluorination of RPCl with antimony trifluoride in pyridine gives alkyldifluorophosphines ; these give five-co-ordinate 1 1 adducts with alcohols and with primary amines (a P-H bond is probably equatorial and the P-F bonds on the other hand secondary amines yield RPF(NR',) which add HF to give salts formulated as [H2NR',] +[RPF4H]-.The unstable Me,PF prepared from active KF and gaseous Me,PCl adds one mole HF to give a product containing a P-H bond possibly Me,PF,H.266b PF,I and PF,Br add across the C=O bond in (CF,),CO;267" when alkylammonium chlorides are re-fluxed in an excess of phosphorus trichloride RN(PCl,) is formed and is converted to RN(PF,) with SbF3.267b Hydrolysis of DPF gives DP(O)(OH), and hydrogen despite a previous suggestion of hydridic character.267c A new method of preparation of HPF4 and H,PF has been described PF being reduced in the gas phase by Me,SnH ;268a trigonal bipyramidal structures with axial fluorines have been assigned spectroscopically for PH2F3,268b PF4C1,268C PF3C12,268d PF3Me2,268e and PF2Me3.268e Pure POBr, AsBr,, and SbBr have been obtained by the action of BBr on Group V oxides and s ~ l p h i d e s .~ ~ ~ The kinetics of the reaction between white phosphorus and iodine have been rein~estigated.',~ Crystalline PBr consists of tetrahedral PBr,' M. Fild I. Hollenberg and 0. Glemser Naturwiss. 1967,54,89; A. H. Cowley and R. P. Pinnell, 263 (a) M. Baudler and W. Valpertz Z . Naturforsch. 1967,22b 222; (b) E. Fluck and H. Binder, 264 (a) G. M. Bogolyubov and A. A. Petrov Dokludy Chem. 1967,173 329; (b) K. Issleib G. Lux, 26 ' D. S. Payne Topics Phosphorus Chem. 1967,485. 266 (a) G. I. Drozd. S. Z. Ivin and V. V. Sheluchenko Zhur. Vsesoyuz Khim. Obshchestva 1967, 12,472,474; G. I. Drozd S. Z. Ivin V. V. Sheluchenko and B. I. Tetel'baum Zhur. obshchei Khim., 1967,37,957; (6) F.Seel K. Rudolph and W. Gomber Angew. Chem. Internut. Edn. 1967,6 708. 267 (a) M. Lustig and W. E. Hill Inorq. Chem. 1967,6 1448; (b) J. F. Nixon Chem. Comm. 1967, 669; (c) R. W. Rudolph and R. W. Parry Inorg. Chem. 1967,6 1070. 268 (a) P. M. Treichel R. A. Goodrich and S. B. Pierce J . Amer. Chem. SOC. 1967 89 2017; (6) J. Goubeau R. BaumgBrtner and H. Weiss 2. unorg. Chem. 1966,348,286; (c) R. R. Holmes 1. Chem. Phys. 1967 46 3718; (6) J. A. Salthouse and T. C. Waddington Spectrochim. Acta (A) 1967 23, 1069; (e) A. J. Downs and R. Schmutzler ibid. p. 681. J . Amer. Chem. SOC. 1966,88,4533. Z. onorq. Chem. 1967 354 113; (c) K. Issleib and G. Harzfeld ibid. 1967 351 18. and R. Stolz Z . anorg. Chem. 1967,350,44. 269 M. F. Lappert and B. Prokai J . Chem. SOC.(A) 1967,129. "O R. L. Carroll and R. P. Carter Znorg. Chem. 1967,6,401 The Typical Elements 265 cations and linear unsymmetrical Br - anions ;271a the dissociation into these ions in nitrobenzene has been The PCl,' ion has been identified in a number of PCl adducts by vibrational spectroscopy272" and 31P n.m.r. of solids.272b The reactions of halogens with phosphorus (111) compounds have been studied in liquid HC1;273" fluorine reacts with PCl to give PC1,F2 and ionic chlorofluorides of phosphorus (v).~~~' Ph,PCl;- ,ClO; are produced by the action of HCIO on Ph,PCI,-, in CH2C12.273C The reaction between Ph,PO(OEt) -,and [Et 30]+ [BF,]- in CH2C1 gives [Ph,P(OEt) -,,I+ [BF,] -, which were used to prepare Ph2POEt and PhP(OEt)2.274a The action of alcohols on PC14+PF6- gives P(OR),+PF6-,274b whilst the (Me2N),PNH2+ ion is formed by the reaction between (Me,N),P and chloramine generated in [PCl,phen] +Cl- [SbCl,phen] 'SbCl; and [AsCl,phen]+SbCl; have been made by the action of 1,lO-phenanthroline on PCl, SbCl, and A s C ~ S ~ C ~ .~ ~ ~ ~ A dark red adduct formulated as the five-covalent phos-phorus derivative (NC),CPCl is formed from PCl and C1C(CN)3.275 The action of KCCR in liquid ammonia on Ph,PCl gives Ph,PCCR stable below -20°c.276 The anions PCl,(CN),- and P(N3)6- have been obtained in salts stabilised by large cations.277 A gas-phase electron-diffraction study of P4010278a and crystal structure determinations of P409,2780 P406S4,278b Me2P(S)P(S)Me2,278' and Me2P(0)OH278d have been reported; short (2.48 A) O-H-O bonds are present in the l q t of these.Equilibria between the adducts P406,nBH3 (n = W) have been studied by 31P n.m.r. in solution and crystalline solids isolated for n = 2 or 3.52a The determination of pKBH+ values in sulphuric acid by an n.m.r. method shows that phosphine oxides are about lo6 times less basic than amine arsine or stibine oxides indicating more n-bond character in the P-0 bond.279 An exhaustive study has been made of the preparation and hydrolysis of pure polyphosphates containing 4-8 phosphorus atoms per molecule ;280a vibrational spectra are consistent with a CJa 'chair' con-271 (a) G. L. Breneman and R. D. Willett Acta Cryst. 1967,23,467; (b) E. Y. Gorenbein and I. L. Abarbarchuk Russ. J . Inorg. Chem. 1966,11 1195. 272 (a) H. Gerding and J.C. Duinker Rev. Chim. minerhale 1966,3 815; P. Reich and H. Preiss, 2. Chem. 1967,7,115; (b) W. Wieker and A. R. Grimmer Z . Naturforsch. 1967,22b pp. 257,283,1220. 273 (a) J. A. Salthouse and T. C. Waddington J . Chem. SOC. (A) 1967 1096; (b) T. Kesavadas and D. S. Payne ibid. p. 1001 ; (c) A. Schmidpeter and H. Brecht Angew. Chem. Internat. Edn. 1967, 79 535. 274 (a) A. Rhomberg and T. Tavs Monatsh. 1967 98 105; (b) L. Kolditz and K. Lehmann Z . Chem. 1967,7 356; (c) S. R. Jain L. K. Krannich R. E. Highsmith and H. H. Sisler Inorg. Chem., 1967,6 1058; (d) M. J. Deveney and M. Webster Inorg. Nuclear Chem. Letters 1967 3 195. 275 A. D. F. Toy and H. J. Emeleus J . Inorg. Nuclear Chem. 1967,29 269. 276 R. Nast and K. Kaeb Annalen 1967,706 75 277 H. W. Roesky Angew.Chem. Internat. Edn. 1967,6 pp. 363,637. 278 (a) B. Beagley D. W. J. Cruickshank T. G. Hewitt and A. Hall Trans. Faraday SOC. 1967, 63,836; (b) F. C. Mijlhoff J. Portheine and C. Romers Rec. Trau. chim. 1967,86,257; (c) C. Pedone and A. Sirigu J . Chem. Phys. 1967,47 339; (d) F. Giordano and A. Ripamonti Acta Cryst. 1967, 22,678. 279 P. Haake R. D. Cook and G. H. Hurst J . Amer. Chem. Soc. 1967,89,2650. 280 (a) E. J. Griffith and R. L. Buxton J . Amer. Chem. SOC. 1967 89 2884; (b) W. P. Griffith, J . Chem. SOC. (A) 1967,905 266 A. J . Downs G. M. Sheldrick and J . J . Turner formation for the M30g3- (M = P or As) and Si,0g6- anions.280b The hydrolysis reactions of P4S10 and P406s4 have been studied;281" P4Sio reacts with water in THF to give H3P03S,281b and salts of HP02S2- have been isolated in the alkaline hydrolysis of P4S3;281c in liquid H,S however, one mole of trimethylamine solvolyses two moles of P,S to give [Me,NH]l[H2P2S6]2- ; the stereochemistry of this anion has been in-vestigated by i.r.and Raman spectroscopy.28 ld Some new anionic substituted thiophosphates have been obtained by the action of P4S10 on certain types of metal salts.28 le Dialkyl disulphides react with primary and secondary phosphines to give RP(SR') and R,PSR' in the presence of radical in-hibitors but otherwise RP(S)(SR') and R,P(S)SR' respectively.282 Alkali metals give (Me2N),POM and MNMe when dissolved in (Me,N),PO ;283a the thermal decomposition of OP(NH,) yields (OPN),.283b The action of anhydrous HI on Me,NP(O)F and Me,NP(S)F gives good yields of HP(O)F, and HP(S)F respectively; the latter is appreciably the more stable.2840 [F,P(O)],O reacts with ammonia to give NH4+P02F2- and H2NP(0)F,,284b and with KSCN to give SCNP(0)F2;284c the action of carboxylic acid an-hydrides on MePF yields MeP(0)F2.284d Fluorination of P(NCS) produces SCNP(S)F and (SCN),P(S)F as well as the expected PF,NCS and PF(NCS)2.284C Although hydrazine gives SP(NHNH,) with SPF, phenyl-hydrazine gives Ph [NH] .P(S)F ;285a similarly HNMeNMe reacts with PCl to give P(NMeNMe2)3.285b Salts of substituted phosphate anions of the types S,PXY - or SOPXY- (X,Y = F C1 CN or N3),286and (Ph0)2PSeS-286b have been prepared ; reactions of the acid (Ph,PS),NH have been studied;286c Ph,P(S)NCO adds 1 or 2 moles of secondary amine to givePhfiS)NHo(S)NRR' and its dialkylammonium salt respectively.286c The reactions of Me,P:NH with metal alkyls have been in~estigated;,~' Me,Si*HC PMe reacts with methanol or trimethylsilanol to give Me,P:CH;288 the protons in this compound are found to be equivalent on an n.m.r.time scale in the presence of a trace of methanol. (CF,),CN PPh is ( a ) G. Nickless F. H. Pollard and D. E. Rogers J . Chem. SOC. (A) 1967 1721; (b) S. J. Brois, Chem. Comm. 1967 1237; (c) J. D. Murray G. Nickless and F. H. Pollard J. Chem. SOC. (A) 1967, 1726; (d) H. Behrens and H. H. Holemann 2. Naturforsch. 1967,22b 1352; (e) H. W. Roesky F. N. Tebbe and E. L. Muetterties J . Amer. Chem. SOC. 1967,89 1272. 282 M. Grayson and C. E. Farley J . Org. Chem. 1967,32,236. 283 (a) H.Normant and J. F. Brault Compt. rend. 1967 264 C 707; (b) T. D. Awxbukh N. P. Bakina and L. V. Alpatova Vysokomol. Soedineniya 1966,8,1754. 284 (a) T . L. Charlton and R. G. Cavell Znorg. Chem. 1967,6,2204; (b) S. Kongpricha and W. C. Preusse ibid. 1967,6 1915; (c) H. W. Roesky Chem. Ber. 1967 100 2142; ( d ) V. V. Lysenko 1. D. Shelakova K. V. Karavanov and S. Z. Ivin Zhur. obshchei Khim. 1966,36 1507. 285 (a) H-G. Horn and 0. Glemser Chem. &r.,'i967,100,2258; (b) J. M. Kanameuller and H. H. Sisler Znorg. Chem. 1967,6 1765. 286 (a) H. W. Roesky Chem. Ber. 1967 100 pp. 1447 2138; (b) N. I. Zemlyandkii and N. M. Chernaya Ukrain khim. Zhur. 1967,33 182; (c) A. Schmidpeter and H. Groeger Chem. Ber. 1967, 100 pp. 3052,3979. H. Schmidbaur and G. Jonas Angew.Chem. Znternat. Edn. 1967,6,449. H. Schmidbaur and W. Tronich Angew. Chem. Znternat. Edn. 1967,6,448 The Typical Elements 267 synthesised by the reaction between triphenylphosphine and (CF3)3CN0,289a R,P N-CN from the reaction of R3P with difluor~diazirine,~~~' and PhP(F,) N-CN by the action of PhPF on bis(trimethylsilyl)carbodi-imide.28gc The product of the reaction between N2F4 and PCl has been assigned the structure C1,P-PC12:NF on the basis of its,reaction with SO to form 0PCl2-PCl2 NF.289d (RNH),PPh rearranges to (RNH),PPh NR (PPh), and RNH,. 289e N.m.r. X-ray diffraction and chemical reactions provide evidence for the structure (35) for the adduct of (CF,),CO with (Ph3P)2C.290 The solvolysis reactions of the *N:PCl group have been studied.29' The crystal structure of [(H,N),P N.P(NHMe),NH,] '1- confirms the nature of the cation;292" the analogous [(H2N)3P],N+C1- has been identified as a product of the reaction of phosphorus pentachloride with ammonia.292b The mesomeric cation [(Ph,PN),N] + produced as an [SbClJ-salt by the action of triphenylphosphine on [SbCl,(N,),], decomposes on heating to the [(Ph,P),N] + cation ;292c (Ph,P),NH (Ph,P),NHCl and (Ph,P,),NCl are produced by the reaction of Ph,PC1 with (Me3Si),NH under various condition^.^ 92d Tertiary phosphinimines and phosphazines have been reviewed.,' The structures (36),'," and (37)294b have been deter-mined by X-ray crystallography ; the vibrational spectra of (MeNPCl,) and (MeNPF,) are consistent with structures analogous to (36).294c The crystal structure of (Br,PN) shows that the (PN) ring is distorted from planarity into a slight 'chair' c o n f ~ r m a t i o n ; ~ ~ ~ " however in 1'1-P,N,F,Ph2 the phosphorus atom attached to the two phenyl groups lies out-of-plane of the other five ring-atoms and it has been suggested that the phenyl groups weaken the delocalised n-bonding to this The three isomeric compounds P,N,Cl,(NHMe) prepared by successive partial replacement of chlorine atoms in trimeric P,N3Cl have been identified as gem- cis- and trans-isomers by dipole-moment measurements,295C and the six possible isomers P3N3Br6-,(NMe,) (n = 1-3) characterised ;295d several compounds of the type P,N,Br,-,F have been obtained by the AgF fluorination of (Br2PN),.295' A variety of products have been produced by the thermal 289 (a) E.P. Mochalina B. L. Dyatkin and I. L. Knunyants Izvest. Akad. Nauk S.S.S.R. Ser. khim. 1966 2247; (b) R. A. Mitsch J . Amer. Chem. Soc. 1967 89 6297; (c) 0. Glemser E. Niecke, and J. Stenzel Angew. Chem. Internat. Edn. 1967 6 709; (d) V. V. Kardashevskii Y. M. Zinoviev, S. P. Makarov and V. A. Ginsburg Russ. J . Inorg. Chem. 1967,12,576; (e) A. P. Lane D. A. Morton-Blake and D. S. Payne J . Chem. Soc. (A) 1967,1492. 290 G. H. Birum and C. N. Matthews J . Org. Chem 1967 32 3554. 291 W. Haubold and M. Becke-Goehring 2. anorg. Chem. 1967,352. 113. 292 (a) M. Ziegler Angew. Chem. Internat. Edn. 1967,6,369; (h) M. Becke-Goehring and B. Scharf Z . anorg. Chem. 1967,353,320; (c) N. Wiberg and K. H. Schmid Angew. Chem. Internat. Edn. 1967, 6,953; (d) H.Noth and L. Meinel 2. anorg. Chem. 1967,349,225. 293 G. Singh and H. Zimmer Organometallic Chem. Rev. 1967 2 279. 294 (a) J. W. Cox and E. R. Corey Chem. Comm. 1967,123; (b) J. Weiss and G. Hartmann Z . anorg. Chem. 1967 351 152; (c) A. J. Downs Chem. Comm. 1967 628; M. P. Yagupsky Inorg. Chem., 1967,6 1770. 2 9 s (a) E. Giglio and R. Puliti Acta Cryst. 1967,22,304; (b) C. W. Allen I. C. Paul and T. Moeller, J . Amer. Chem. Soc. 1967,89 6361; (c) W. Lehr Z . anorg. Chem. 1967 352 1967; (d) R. Stahlberg and E. Steger J . Znorg. Nuclear Chem. 1967,29,961; ( e ) E. Steger and D. Klemm J . Znorg. Nuclear Chem. 1967,29,1812 268 A. J . Downs G. M . Sheldrick and J . J Turner decomposition of Ph,P(S)(NHR),- (n = 1 or 2) depending on the nature of R e.g. (38) and (39).296 04% Ph3P-c I t 0-C -CF3 I C F3 (35) Me Ph \ I -N b Ph' Me (37) (38) Arsenic.Absorption bands observed in the isothermal flash photolysis of AsCl have been attributed to AsCl.,'' The hydrides EH3298a and anions EH2- 298b (E = P As or Sb) have been studied by n.m.r. Tertiary arsines have been synthesised via the alkali-metal derivatives MAsMe,.," Ammonolysis of arsenic and antimony triphenyls with KNH in liquid ammonia yields K[As(NH,),] and K[Sb(NH,),] but explosive BiN is formed from bismuth tri~henyl.~OO R2AsI react with acetylenic Grignard reagents in ether to give R,ASCCASR,.~~'" Mercury reacts with C6F,AsC1 to give (C,F,As), and with (C6F,),AsCl to form [(C,F,),As], probably a mixture of two The low-temperature reaction between (CF,),AsCl and 1,l-dimethylhydrazine in ether produces M~,NNHAS(CF,),.~~ X-Ray crystallography shows that the (AsN) ring in (ClAsNMe) is not planar,302a and that As4(NMe) has a molecular structure related to that of adamantane.,',' S-S bonds are cleaved by dimethylarsine and As-As bonds cleaved by CF,SCl the reactions of thioarsolanes have been studied cyclic systems are prepared by the re-actions of As,06 with HS*CH,-CH,*SH and HO*CH,*CH,-SH.303b Ph,AsOH+X- (X = C1 or Br) behave as weak electrolytes in acetonitrile, 296 R.A. Shaw and E. H. M. Ibrahim Angew. Chem. Internat. Edn. 1967,6,556; E. H. M. Ibrahim 297 N. Basco and K. K. Yee Chem. Comm. 1967,1255. 298 (a) E. A. V. Ebsworth and G. M. Sheldrick Trans. Faraday SOC. 1967 63 1071 ; (b) G. M. 299 J. R. Phillips and J.H. Vis Canad. J . Chem. 1967,45,675; R. D. Feltham A. Kasenally and '0° 0. Schmitz-DuMont and B. Ross Z . anorg. Chem. 1967,349,328. and R. A. Shaw Chem. Comm. 1967,244. Sheldrick ibid. 1967,63 1065. R. S. Nyholm J . Organometallic Chem. 1967,7 285. (a) K. I. Kuz'min and L. A. Pavlova Zhur. obshchei Khim. 1966,36 1478; (b) M. Green and D. Kirkpatrick Chem. Comm. 1967 57; (c) L. K. Peterson and K. I. ThC Chem. Comm. 1967 1056. '02 (a) J. Weiss and W. Eisenhuth Z . Naturforsch. 1967,22b 454; (b) J. Weiss and W. Eisenhuth, Z . anorg. Chem. 1967 350 9. '03 (a) W. R. Cullen and P. S. Dhaliwal Canud. J . Chem. 1967,45,379 ; (b) K. Sommer and M. Becke-Goehring Z . anorg. Chem. 1967,355 pp. 182,192 The Typical Elements 269 but the corresponding Br,- and IC1,- salts are strong electrolytes.304 The anions (F,As),02- and (F,Sb),O2- have been obtained as condensation products of AsF,OH- and SbF,OH- and vibrational spectra suggest that the oxygen bridges are non-linear ; the four-membered ring anion (AsF,O)g-was also identified.,"" Tetra-alkylammonium salts of AsF,X- (X = Cl Br, OMe OEt) were also obtained from AsF,OH- salts.305b Several methods for the preparation of M + As(OR) - ,,F,,- have been given ; thermal decomposi-tion of LiAS(OCH,)6 yields A S ( O M ~ ) .~ ~ ~ ' Antimony. The change in the atomic arrangement between the para- and ferro-electric phases of SbSI has been elucidated by crystal structure deter-m i n a t i o n ~ . ~ ~ ~ ~ Kermesite (Sb,O,S,) has a layer type structure ; the Sb-S interlayer distance is 3.40 A.306b The compounds (Me,M),Sb (M = C Si, Ge or Sn) have been synthesised from the corresponding chlorides and Li3Sb;,07' Ph,SbCl reacts with HCiC-MgBr in THF to give Ph,Sb*Ci CH.307b The co-ordination of Sb in the crystal structure ofthe chelate compound Sb(S-CH,*CO,),H is best described as a distorted trigonal bi-pyramid with axial oxygen atoms and equatorial 'lone pair' and two sulphur atoms.308 The Raman spectra of aqueous solutions of Me,Sb(NO,) and Me3Sb(C10,) provide evidence for a planar Me3Sb2+ cation; in solid Me,Sb(NO,) the molecule is probably trigonal bipyramidal with axial covalently bonded NO Me,Sb(SBz) (Bz = benzoyl) appears to be in equilibrium with Me,Sb and (SBz) in hot benzene.309b Pentaethylstibine is produced by the action of lithium or magnesium ethyls on Et,SbCl,-,: it reacts with methanol to give Et,SbOMe and with AlEt,Cl,- to give 1 1 and 1:2 ad duct^.^" R,Sb react with chloramine to give (R,SbCI),NH, which can be hydrolysed to (R3SbC1),0;31'a C1,O converts SbFCl in CCI, to a precipitate of SbOFCl ;31 lb Ph3Sb0 obtained from tetraphenylstibonium hydroxide is not identical with the dehydration product of Ph,Sb(OH)2.31 I' Ph,SbCl has a trigonal bipyramidal structure in the crystal.312 The crystal structures of Ph2SbC13,0H,,3 l3 SbCl,,NCMe,3 SbC1,,02NMe,314b and '04 G.S. Harris and F. Inglis J . Chem. SOC. (A) 1967,497. '05 (a) L. Kolditz and M. Gitter Z . Chem. 1967,7 202 240; Z . anorg. Chem. 1967; 354 15; (b) L. Kolditz and H. P. Krause Z . Chem. 1967,7,157,240; (c) L. Kolditz and G.Riesel Z . anorg. Chem., 1967,355,170. 306 (a) A. Kikuchi Y. Oka and E. Sawaguchi J . Phys. SOC. Japan 1967 23 337; (b) V. Kupcik, Naturwiss. 1967,54 114. '07 (a) E. Amberger and R. W. Salazar J . Organometallic Chem. 1967,8,111; (b) A. N. Nesmeyanov, A. E. Borisov and N. V. Novikova Dodlady Chem. 1967 172 172 'On I. Hansson Chem. Comm. 1967,173. '09 (a) A. J. Downs and I. A. Steer J . Organometallic Chem. 1967 8 P21; (b) Y. Matsumura M. 'lo Y. Takashi J . Organometallic Chem. 1967,8 225. '11 (a) R. L. McKenney and H. H. Sisler Inorg. Chem. 1967 6 1178; (b) K. Dehnicke and U. Miiller Z . Naturforsch. 1967,22b 263; (c) G. H. Briles and W. E. McEwen Tetrahedron Letters, 1966,5299. Shindo and R. Okawara Inorg. Nuclear Chem. Letters 1967,3,219. '12 T. N. Polynova and M.A. Porai-Koshits Zhur. strukt. Khim. 1966,7 742. 313 T. N. Polynova and M. A. Porai-Koshits Zhur. strukt. Khim. 1967,8 112. 314 (a) H. Binas Z . anorg. Chem. 1967,352,271 ; (b) L. Riesel and H. A. Lehmann Z . Chem. 1967, 7,316; (c) Y. Hermodsson Acta Chem. Scad. 1967 21 1313 270 A. J . Downs G. M . Sheldrick and J . J . Turner SbCl,,0SeC1,3 14' all involve octahedral co-ordination of antimony. N.q.r. spectra are consistent with analogous structures for SbCl,,OPCl and SbCl,,NCMe but show that a phase change occurs between 195 and 210°K in SbCI,. Whilst the high-temperature form is probably discrete trigonal-bipyramidal molecules the low-temperature form involves chlorine bridges.,' The reaction between acetylacetone HC1 and PhSbO(OH) yields PhSbCI,[CH(COMe),] ; n.m.r.spectra are consistent with an octahedral structure with axial ~hlorines.~ l6 Bismuth. Evidence has been presented for the existence of Bi+ Bis3+ and Bi,2+ in molten salts.317 The thermochemistry of the reaction between BiCl, and bismuth to give BiCl(g) has been in~estigated.~~ The ions BiC14-, BiCl,,- and B Q 3 - have been identified in aqueous solution by Raman spectroscopy; it is suggested that BiClS2 - is square pyramidal and BiC1,3 -octahedral. The highest charged bromo-species identified was BiBr, -, not BiBr,' - as previously claimed.319" Spectrophotometric evidence suggests the existence of BiI,4- Bi16,- Bi14- and solvated BiI in aqueous solution, but no evidence is found for the species BiI,,- previously reported;319b the discrete Bi,Ig3- ions in crystalline Cs,Bi,I consist of two distorted octahedra sharing a common face.319c The reaction between Me,GeCI and Na,Bi in liquid ammonia gives (Me3Ge),Bi.320 Evidence has been presented for the formation of a deep blue bismuthonium ylid in molten triphenylbismuth (40).Ph Ph Ph Ph BiPh3 '+ Ph 140" [phQph-phQp] BiPh BiPh, (40) Group M.-Oxygen. The reactions of molecular oxygen322 and of ozone with alkenes,, have been reviewed. There is recent spectroscopic evidence for ( 0 2 ) 2 3 2 4 0 3 although low-temperature i.r. spectra indicate the contrary.325 31s R. F. Schneider and J. V. Dilorenzo J . Chem. Phys. 1967,47,2343. 316 Y . Kawasaki and R. Okawara Bull. Chem. SOC. Japan 1967,40,428. 317 J. D. Corbett Inorg. Nuclear Chem. Letters 1967 3 173; N.J. Bjerrum C. R. Boston and G. P. Smith Inorg. Chem. 1967,6 1162; N. J. Bjerrum and G. P. Smith Inorg. Chem. 1967,6,1968. 318 D. Cubicciotti J . Phys. Chem. 1967,71,3066. 319 ( a ) R. P. Oertel and R. A. Plane Inorg. Chem. 1967,6 1960; (b) A. J. Eve and D. N. Hume, ibid. p. 331 ; (c) A. Nystrom and 0. Lindqvist Acta Chem. Scand. 1967,21,2570. 320 I. Schumann-Ruidisch and H. Blass Z . Naturforsch. 1967,22b 1081. 3 2 1 D. Lloyd and M. I. C. Singer Chem. Comm. 1967 1042. "' S. Fallab Angew. Chem. Internat. Edn. 1967,6 496. 323 A. T. Menyailo and M. V. Pospelov Russ. Chem. Rev. 1967,36,284. 324 (a) R. P. Blickensderfer and G. E. Ewing J . Chem. Phys. 1967,47,331; (b) T . V. Yagodovskaya, 325 B. R. Cairns and G. C. Pimentel J. Chem. Phys. 1965,43,3432. L. I.Nekrasov and N. P. Klimushina Russ. J . Phys. Chem. 1967,41,474 The Typical Elements 27 1 Firm evidence has now been obtained from e.s.r. spectra for the formation of OH during y-irradiation of i ~ e . ~ ~ ~ ~ . ~ The chemical shift of OH- (and SH-, SeH-) has been determined (T = There is mass spectral evidence for H,0328 but about the peroxy-radical condensates (i.e. HO, H203 and H204) persists. Raman and far-i.r. spectra indicate3" (MeHg),O+ to be almost planar whereas (MeHg),S+ is pyramidal. The chemistry of alkoxy-radicals (RO) has been reviewed ;33 l a there has been extensive structural and chemical work3,' on organic peroxides and peroxy radicals. The reaction of Pb(OAc) with Bu'0,H produces a species stable to - 35"c and which is probably But203 below ca.- 70"c kinetic and e.s.r. evidence suggest the formation of BUt204332b and that the original reported preparation332c of But204 gave But203 instead. Perfluoroalkoxy salts (OCF,R,-) have been ~ r e p a r a r e d ~ ~ ~ " ~ 333 by the reaction of CsF or RbF with R,C(O)F; e.s.r. spectra show the formation of the radical CF3*C02 on y-irradiation of CF3C02NH4.334 The first synthesis of perfluoro di-epoxides Photolysis of a solution (liquid) of CF,OF or CF,O,CF in a CF4-CF,Cl mixture below -19O"c gives e.s.r. evidence for the formation of CF,02, which exhibits restricted rotation of the CF3 The first compounds containing two OF groups have been prepared: CF,(OF) 337 (best prepared by the reaction of CsF with COF2337-), FO(CF2)nOF,337d CF3CF(OF)2 and (CF,),C(OF)2.337e The U.V.photolysis of a F2-(FC0)20 mixture produces FC(0)OF which can be further oxidised (a) G. H. Dibdin Trans. Faraday Soc. 1967 63 2098; (b) J. A. Brivati M. C. R. Symons, D. J. A. Tinling H. W. Warddle and D. 0. Williams ibid. p. 2112. 327 G. M. Sheldrick Trans. Faraday Soc. 1967,63 1065. 328 C. E. Melton and H. W . Joy J. Chem. Phys. 1967,46,4275. 329 (a) R. A. Jones and M. Venugopalan Canad. J. Chem. 1967,45,2452; (b) T. V. Yagodovskaya and L. I. Nekrasov Russ. J. Phys. Chem. 1966,40 698; ( c ) T. V. Yagodovskaya and L. I. Nekrasov, ibid. 1967 41 108; (d) T. V. Yagodovskaya N. P. Klimushina L. I. Nekrasov and Yu. A. Pentin, Rum. J . Phys. Chem. 1967,41 369. 330 J. H. R. Clarke and L. A. Woodward Spectrochim. Acta 1967,23A 2077. 331 (a) C. Walling Pure Appl.Chem. 1967 15 69; (b) M. Sax and R. K. McMullan Acta Cryst., 1967 22 281; D. C. McKean J. L. Duncan and R. K. M. Hay Spectrochim. Acta 1967 23A 605; W. J. Maguire and R. C. Pink Trans. Faraday SOC. 1967 63 1097; H. W. Wasserman and J. R. Scheffer J. Amer. Chem. Soc. 1967 89 3073; E. G. Janzen F. J. Johnston and C. L. Ayers ibid., p 1176; J. C. W. Chien and C. R. Boss ibid. p. 571. 332 (a) P. D. Bartlett and P. Gunther J. Amer. Chem. Soc. 1966,88 3288 (cf. Ann. Reports 1966, 63 p. 177); (b) P. D. Bartlett and G. Guaraldi ibid. 1967,89,4799; (c) N. A. Milas and S M. Djokic, Chem. and Ind. 1962,405. 333 M. E. Redwood and C. J. Willis Canad. J. Chem. 1967 45 389; F. Seel R. Budenz and W. Gombles Angew. Chem. Internat. Edn. 1967.6.256. 334 F. D. Seygley and W.Gordy J. Chem. Phvs 1967,46,2245. 335 I. L. Knunyants V. V. Shokin and I. V. Galakhov J. Gen. Chem. (U.S.S.R.) 1966 36 1973. 336 N. Vanderkooi jun. and W. B. Fox J. Chem. Phys. 1967,47 3634. 337 (a) F. A. Hohorst and J. M. Shreeve. J. Amer. Chem. Soc. 1967.89. 1809 (h) P. G. Thompson, ibid. p. 1811; (c) R. L. Caubie and G. H. Cady ibid. p. 1962; (d) J. H. Prager J. Org. Chem. 1966,31, 392; M . Lustig A. R. Pitochelli and J. K. Ruff J . Amer. Chem. Soc. 1967,89,2841; (e) P. G. Thompson and J. H. Prager ibid. p. 2263 272 A. J. Downs G. M . Shedlrick and J . J . Turner by F and CsF to CF2(OF)z.338 The colourless explosive FO*CF,OOCF,=OF is produced by the reaction of F,-KF on (FC02)02.339 The surprisingly stable compound CF3000CF3340a~ is best prepared3,'" by the reaction of OF2 and COF with a CsF catalyst ; there is some evidence340b for the forma-tion of CF30000CF3.Although the only direct evidence for the OF radical still comes from matrix isolation the bond energy has been estimated as ca. 53 kcal./mole from the kinetics of decomposition of and >40 kcal./mole from the reaction at 4 0 ~ of F with N,0.341b The symmetrical doublet in the "0 n.m.r. spectrum of liquid '03F2' suggests342" that there is no such compound whereas mass spectral data have been interpreted342b as indicating that its structure in the condensed state is FO,*OF the possibility that the material consists of 02F2 plus 'interstitial' 0 has been suggested.342c Photolysis of C1,O in a matrix at 1 4 " ~ produces ClClO and probably (C10)2;343a similar photolysis of ClO or of C1 in 0 gives C100 the i.r.spectrum indicating 343b a high 0-0 stretching frequency and hence a short 0-0 bond as in OzF; there is also e.s.r. spectral evidence343c for the formation of ClOO on photolysis of CIOz in KC104. The new explosive chlorine oxide 0 n' ClO,. (probably 'c1-Cl-0) has been prepared344 by decomposing CIOz. The vibration2 spectra of Br0,- are said to indicate345" that 2p -+ 4d, bonding is as effective as 2p + 3d bonding (in ClO,-) and hence vitiates one explanation for the non-existence of Br04-.349 The i.r. spectra of Br160n1803-n- have been obtained by the reaction of (Br02)x produced by electric discharge with a CsI window ;345b Ba(BrOz) has been preparedJ4,' by the thermal decomposition of Ba(BrO,),. The chemistry of FC103 has been reviewed.346 X-Ray diffraction of IOF3 a molecular structure similar to the I02F2- ion i.e.not containing Sulphur. The general reaction H,S + Cl,S -* 2HC1 + SX+?. has been 10 + ; microwave confirm the C, structure of IOF,. 338 R. L. Cauble and G. H. Cady J . Amer. Chem. SOC. 1967,89,5161. 339 M. Lustig and J. K. Ruff Chem. Comm. 1967,870. 340 (a) L. R. Anderson and W. B. Fox J . Amer. Chem. SOC. 1967,89 4313; (b) P. G. Thompson, ibid. p. 4316. 341 (a) J. Froe H. Gg. Wagner and G. Weden Z. phys. Chem. (Frankfurt) 1967,56 238; (b) J. S. Ogden and J. J. Turner J . Chem. SOC. (A) 1967,1483. 342 (a) I. J. Solomon J. K. Raney A. J. Kacmarek R. G. Maguire and G. A. Noble J . Amer. Chem. SOC. 1967 89 2015; (b) T. J. Malone and H. A. McGee J .Phys. Chem. 1967 71 3060; (c) J. W. Nebgen F. I. Metz and W. B. Rose J . Amer. Chem. SOC. 1967,89 3118. 343 (a) M. M. Rochkind and G. C. Pimentel J . Chem. Phys. 1967 46 4481; (b) A. Arkell and I. Schwager J . Amer. Chem. SOC. 1967,89 5999; (c) R. S. Eachus P. R. Edwards S. Subramanian, and M. C. R. Symons Chem. Comm. 1967,1036. 344 E. T. McHale and G. von Elbe J . Amer. Chem. SOC. 1967,89,2795. 34s (a) J. C. Evans and G. Y-S. Lo Znorg. Chem. 1967,6 1483; (b) C. Campbell and J. J. Turner, J . Chem. SOC. (A) 1967 1241; (c) B. Tanguy B. Frit G. Turrell and P. Hagenmuller Compt. rend., 1967,264 C 301. 346 V. M. Khutoretskii L. V. Okhlobystina and A. A. Fainzil'berg Russ. Chem. Rev. 1967,36,145. 347 (a) J. W. Viers and H. W. Baird Chem. Comm. 1967 1093; (h) S. B. Pierce and C.D. Cornwell, J . Chem. Phys. 1967,47 1731 The Typical Elements 273 used348a to prepare SI2 which is more stable than S6 or Slo and has a ‘zig-zag’ ring structure ;348b S12 has also been detected in sulphur melts.348c Calcula-tions have been described349 of the energetics of S and Se catenation and ring formation. Further reactions of S atoms have been ~tudied.~” Mass spectra from the crystalline products obtained by solvent extraction of the high-temperature reaction mixtures of S and Se3”” and also S and Te,351b indicate the formation of all species SnSe8- (n = 0-8) and S,Te. A compendium of the synthesis of compounds of S containing S bound to halogen N 0 S or P and other partially halogenated groups has been published.352 The stability constants of AgL AgHL’ and AgL2- [L = RC6H4S (or Se) CH2*C02-] show that Se complexes are more stable than the corresponding S cornplexe~.~’~ The crystal structures of (i) [(~-CSH5)MoO],S, (ii) [SCO~(CO),]~S, and (iii) [MeSFe2(S0),]2S demonstrate the first examples of (i) double-bridging S atoms Mo ,Mo,,~& (ii) a disulphide bridging-group symmetrically co-ordinated to four transition-metal atoms, 54b and (iii) four metal atoms bridged by tetrahedral S which is donating six electrons to the metal atoms.354c Measurement of i.r.and electronic spectra and dipole moments on PhSH p-NO -C6H4* SH and 0-NO CsH4* SH indicate the formation of a stable intramolecular hydrogen bond in the latter.355 The reactions of thiyl radicals (RS-) have been reviewed:356” EtS. has been de-tected from the e.s.r.spectra of X-irradiated EtSH and Et,S at 7 7 ° ~ . 3 5 6 b The reaction of CF,SSCF with Hg and HCl gives CF,SH;303a CF3SSCF3 is produced by U.V. photolysis of a CF,SCl-CO mixture.357 Among new organo-sulphur compounds are (41),358a (42),358b (43) and (44).358c pK Values S /‘ S ’*’ (a) M. Schmidt and E. Wilhelm Angew. Chem. Internat. Edn. 1966,5,964; (b) A. Kutoglu and 349 J. A. Semlyen Trans. Faraday SOC. 1967,63 pp. 743,2342. 3 5 0 E. M. Lown E. L. Dedio 0. P. Strausz and H. E. Gunning J. Amer. Chem. SOC. 1967 89, 1056; P. Fowles M. de Sorgo A. J. Yarwood 0. P. Strausz and H. E. Gunning ibid. p. 1352; 0. P. Strausz J. Font E. L. Dedio P. Kebarle and H. E. Gunning ibid. p. 4807; W. D. McGrath, T. Morrow and D. N. Dempster Chem. Comm. 1967 576.351 (a) R. Cooper and J. V. Culka J . Inorg. Nuclear Chem. 1967,29 1217; (b) R. Cooper and J. V. Culka ibid. p. 1877. 352 C. Hennart Bull. SOC. chim. France 1967,4395. 353 L. D. Pettit A. Royston C. Sherrington and R. J. Whewell Chem. Comm. 1967 1179. 354 (a) D. L. Stevenson and L. F. Dahl J. Amer. Chem. SOC. 1967,89 3721 ; (b) D. L. Stevenson, V. R. Magnuson and L. F. Dahl ibid. p. 3727; (c) J. M. Coleman A. Wojcicki P. J. Pollick and L. F. Dahl Inorg. Chem. 1967,6 1236. 355 A. E. Lutskii A. K. Kul’chitskaya E. M. Obukhova S. A. Volchenok and G. I. Sheremet’eva, J . Gen. Chem. (U.S.S.R.) 1967 36 1579. 356 (a) E. C. Kooyman Pure Appl. Chem. 1967 15 81; (b) S. B. Milliken K. Morgan and R. H. Johnsen J . Phys. Chem. 1967,71 3238. 351 B. W. Tattershall and G.H. Cady J. Innrg. Nuclenr Chem 1967. 29 2819. E. Hellner ibid. p. 965; (c) M. Schmidt and H. D. Block ibid. 1967 6 955. (a) K. Hartke and I-. Peshkar Angew. Chern. Intrrncrt. Edn 1967. 6. 83 ( h ) S. C. Cohen. M. L. N. Reddy and A. G. Massey Chm. Comm. 1967 451; (c) F. Feher and B. Degen Angew. Chem. Internat. Edn. 1967,6,703 274 A. J . Downs G. M . Sheldrick and J . J . Turner for aromatic sulphur compounds containing sulphone sulphonium and sulphoxide groups are said to indicate359" an increase in electron donation to the d orbitals of S in excited states; in simple sulphides the ground and excited states behave similarly359" and it has been argued359b from near U.V. spectra that the concept of localised vacant-orbital participation is unsatis-factory.X-Ray crystallography confirms?60 the R,P(S)P(S)R structure for R4P,S2 rather than the R,P PR previously suggested by n.m.r. Evidence is presented for the transient existence of (45)361 containing tetravalent S, which has long been suggested as having a significant contribution to the structure of thiophen itself. /"\ 'S/ (45 ) (46) E.s.r. spectra of S2- S 2 0 - S203- and SO4- have been described.362 The cryoscopic constant of H2S207 has been measured (5.9) and self-ionisation 2H2S207 + H2S301 + H2S04 + H,S04+ + HS3OI0-postulated.363 Condensation of SOCl with naphthalene-2-thiol gives (CloH7)2S,0 the first stable compound with the -S-S(0)-S 1.r. spectra that the p, + d (0 -+ S ) bonding can be correlated 359 (a) E. L. Wehry J . Amer. Chem. SOC. 1967 89 41; (6) J.Degani A. Mangini A. Frombetti, 360 C. Pedone and A. Sirigir J . Chem. Phys. 1967 47 339. 361 M. P. Cava and N. M. Pollack J . Amer. Chem. SOC. 1967,89 pp. 3639 3640 3641. 362 J. R. Morton J . Phys. Chem. 1967,71,89. 363 R. J. Gillespie and K. C. Malhotra J . Chem. SOC. (A) 1967 1994. 364 R. Steudel P. W. Schenk and J. Bilal 2. anorg. Chem. 1967 353,250. 365 (a) M. Spoliti S. M. Chackalackal and F. E. Stafford J . Amer. Chem. SOC. 1967 89 1092; (b) Yu. I. Naumov L. N. Drozdov and V. A. Izmail'skii Russ. J . Phys. Chem. 1966 40 1037; (c) H. P. Gervais Compt. rend. 1967 264 C 1027. and C. Zauli Spectrochim. Acta 1967,23A 1351 The Typical Elements 275 with the frequency of the S-0 stretching vibration in XzSOz (X = Me or halogen) and that the n electrons in the S-0 bond participate slightly365b in conjugation involving the structure (46).The electronic structure of sulphones has been discussed with particular reference to def~rmation.~~" The spectroscopic evidence366" for the RS(OZ)SR [rather than RS(O)S(O)R] structure of disulphur dioxides has been confirmed366b by an X-ray study on Br *C6H4* S(02)S *C6H,- Br. The reaction of zinc alkyl sulphinate with CF,. SCl gives the new thiosulphonate RSOZSCF whose chemistry is very different from that of other thios~lphonates.~~~ The chemistry of sulphines and sulphenes has been reviewed.368 The radicals SF and SeF have been detected369 by gas phase e.s.r. Doubt has been about the reported preparation of SF and there has been controversy370b over the nature of the exchange process in SF4.The vibrational spectra of solid MC14,SbC15,371" and MC14,A~F5371b (M = S, Se or Te) confirm the presence of the MC13+ C3y ions; the vibrational spectrum of SF,CF suggests371c that the rotational barrier of the CF group is low. Conductivity measurements imply that even strong Lewis bases (e.g. pyridine) displace Cl- from SzClz with difficulty.37z 1.r. and n.m.r. provide evidence373 for the existence of the intermediate sulphenyl fluorides (CF,Cl - .SF) which rapidly rearrange to CF + lC1z -,,SCl. Spectral suggest that the unstable Cs+OSF,- is formed in the reaction of CsF with SOF4 (CsF with PF,O and PF,S forms PFzOZ- and the new PFzSz-);374",b no SFsO derivatives were obtained in reactions of SF,OF with halogens NOz, or PF3.374c With SbCl, FzSz06 reacts at 3"c to form a compound with ratio Sb FSO ch.3 ~ 5 ; ~ ~ ~ ~ with PSF,Br PSFZOS(Oz)F is formed.375b Properties of XSO,- compounds which have been examined include heats of formation of the crystal structures of NO+C1S0,-376b and HzNOS03H,376c preparation of BrS03-,376d and crystal structure of KFSO (where the SO and SF bond lengths of 1.43 and 1-58 A are said to indicate ca. 67% double-bond character in the s-0 bond with a single s-F bond).376' The highest 366 (a) S. S. Block and J. P. Weidner Appl. Spectroscopy 1966,20,73;(b) J. H. Noordvik and A. Vos, Rec. Trau. chim. 1967,86 156. 36' S. S. Block and J. P. Weidner Nature 1967 214,478. 369 A. Carrington G. N. Currie P. N. Dyer D. H. Levy and T. A. Miller Chem. Comm. 1967,641. 3 7 0 (a) R. D.Brown and G. P. Pez Austral. J . Chem. 1967 20 2305; (b) E. L. Muetterties and W. D. Philips J . Chem. Phys. 1967,46,2861; R. L. Redington and C. V. Berney ibid. p. 2862. 3 7 1 (a) I. R. Beattie and H. Chudzynska J . Chem. Soc. (A) 1967 984; (b) W. Sawodny and K. Dehnicke 2. anorg. Chem. 1967 349 169; (c) J. E. Griffiths Spectrochim. Acta 1967 23A 2145. 372 H. G. Heal and J. Kane J . Znorg. Nuclear Chem. 1967,29 1539. 373 F. Seel W. Gombler and R. Budenz Angew. Chem. Internat. Edn. 1967,6 706. 374 (a) M. Lustig and J. K. Ruff Inorg. Chem. 1967,6 2115; (b) H. W. Roesky F. N. Tebbe and E. L. Muetterties J . Amer. Chem. Soc. 1967,89 1272; (c) B. W. Tattershall and G. H. Cady J . Znorg. Nuclear Chem. 1967,29 3003 375 (a) R. E. Noftle and G. H. Cady J . Inorg. Nuclear Chem.1967,29,969; (b) M. Lustig Anyew. Chem. Internat. Edn. 1967,6,959. 376 (a) G. W. Richards and A. A. Woolf J . Chem. Soc. (A) 1967 1118; (b) Th. Hohle and F. C. Mijlhoff Rec. Trau. chim. 1967,86 1153; ( c ) N. C. Baenziger R. F. Belt and C. V. Goebel Znorg. Chem. 1967 6 511; (4 S. Noel M. Wartell and J. Henbel Compr. rend. 1967 264 C 446; (e) K. O'Sullivan R. C. Thompson and J. Trotter J . Chem. Soc. ( A ) 1967 2024. G. Opitz Angew. Chem. Internat. Edn. 1967,6 107 276 A. J . Downs G. M . Sheldrick and J . J . Turner pure polysulphuryl chloride S401 lC1 has been obtained by distillation of the S,03,-1C12 mixture formed from SO and CC14.377 The reaction of XCO SCl(X = F,Cl) and AgCNO produces a halogenyl-sulphur pseudo-halide (X-CO-S-NC0).378 The nature of the K S-N bond has been the subject of further study vibra-tional spectral data show a linear relationship between the wavelength of S-N stretching vibration and bond length and the degree of x-bonding is de-duced;379a the n.m.r.non-equivalence at low temperature of the two methyl groups in Cl,CS(O)NMe has been interpreted as being due to restricted rotation379b but this has been and by analogy with the n.m.r. behaviour of Cl,CSN(CH,Ph) the non-equivalence has been attributed to slow inversion at the N. The crystal structure of Me,SNS(O,)Me shows S1v-N-Sv' distances of 1-63 and 1-58 which is interpreted as indicating379d." a de-localised d,-p,-d system it is noteworthy that the involvement of the Svl in this interaction does not affect the S-0 bond lengths. New e.s.r.spectral data suggest that solutions of S4N4 in concentrated H2S04 contain S2N2+ rather than SN,+.380 The reaction of BF with S4N4 in suspension in CH,Cl gives S4N4*BF,,381" (the B being bonded to the N),381b whereas 4S4N4*BF3 is produced with solid S4N4.381C It is suggested381d that in SOCl, S4N4 and Se2C1 react to f6rm S4N,C1 and (SeS,N,) SeC1,(47) the originally reported product of the reaction (SeS,N,Cl,) being a mixture of the two. Neutron diffraction on S4N4H4 confirms that the hydrogen atoms are bonded to the nitrogen atoms,382 and X-ray work has the mass spectral evidence383b that the reaction between C1,CSCl and NH in benzene-water gives the tetramer (48). A range of new compounds containing the SF, N* (Y) and OSF,:N- (Z) groups have been prepared (Y)CN and (Y)CF,(Y) are + or (47) 37' K.Stoppeka and V. Grove 2. anorg. Chem. 1967,353 72. 378 A. Haas and H. Reinke Angew. Chem. Internat. Edn. 1967,6,705. 379 (a) A. J. Bannister L. F. Moore and J. S. Padley Spectrochim. Acta 1967. 23A 2705; H. Garcia-Fernandez Compt. rend. 1967,265 C 88; (b) H. J. Jakobsen and A. Senning Chem. Comm., 1967 617; ( c ) M. Raban ibid. p. 1017; (d) A. Kilman Acta Cryst. 1967 22 501; (e) A. Kucsman, A. Kalman and I. Kapovits Acta Chirn. Acad. Sci. Hung. 1967 53 97. 380 D. A. C. McNeil M. Murray and M. C. R. Symons J . Chem. SOC. (A) 1967 1019. '*' (a) K. J. Wynne and W. L. Jolly Inorg. Chem. 1967,6,107; (b) M. G. B. Drew D. H. Templeton, and A. Zalkin Inorg. Chem. 1967,6 1906; (c) 0. Glemser and H. Ludemann Angew. Chem. Internat.Edn. 1958 70 190; (d) A. J. Bannister and J. S. Padley J . Chem. SOC. (A) 1967 1437. 382 T. M. Sabine and G. W. Cox Acta Cryst. 1967,23,574. (a) A. C. Hazell Acta Chem. Scand. 1967 21 415; (b) A. Senning and P. Kelly ibid. 1966, 20,2261 The Typical Elements 277 obtained from M3,SiNCNSiMe3 and SF4384a-C ; with SOF, (Z)CN384b is produced which with excess SF gives surprisingly (Z)CF3 ; SF and CF,SNH, give (Y)CF and CF,SNSNSCF,,384d and SF4 and SOF with FSO,NH, give FS02(Y)384e*g and FS02(Z)3841 respectively. FCO(Y) and C1S02(Y)384g have also been prepared; OPF,NH2 forms OPF,(Y) with SF4.384f 1.r. evidence suggests the formation of the NSF,O- anion in the reaction of Ph,AsBr and HNSF,0.2s3b Other compounds with an N:S bond include MeC(0)NSO (from MeC(O)N(SiMe,) + SOCI,) 3850 NCNSO (from Me,SiNCNSiMe + SOCl,),253a FS0,NSO (from FSO,NH + SOCl,) which with PCl gives FSOzNSC12.38sb N-sulphinyl sulphuryl chloride [OSNSO,Cl] is prepared386 from the reaction of PCI,:NSO,CI and SO,; FS0,N CC1 is obtained from the reaction of SbF on ClSO,N:CCI which is prepared from ClS0,NCO and PC1s.171 Two stable members of a new type of sulphuryl amide series MeC( NH2+Cl -)NHS0,NH2 and MeC( :NH) NHSO,NH have been prepared from O,S(NH,) and MeC( NH)NH,.387 Selenium.The chain structure of amorphous Se has been confirmed by heat capacity and the crystal structure of trigonal Se deter-mined.388b The weakly basic ylid (49) has been prepared.389 Linkage isomerism Se- Se SePh I I FjC*=C+CFj Ph li-7 N N b e ’ 384 (a) W. Sundermeyer Angew.Chem. Internat. Edn. 1967 6 90; (b) M. Lustig and J. K. Ruff, Inorg. Nuclear Chem. Letters 1967,3,531; (cj 0. Glemser V. Biermann and A. Hoff 2. Naturforsch, 1967,226,893; (d) A. Haas and P. Schott Angew. Chem. Internat. Edn. 1967,6 370; (e) 0. Glemser, H. W. Roesky and P. R. Heinze ibid. p. 179; v) 0. Glemser H. W. Roesky and P. R. Heinze ibid., p. 710; (g) U. Biermann and 0. Glemser Chem. Ber. 1967 100 3795. ”’ (a) 0. J. Scherer and R. Schmitt Z . Naturforsch. 1967 22b 224; (bj H. W. Roesky Angew. Chem. Internat. Edn. 1967,6 711. J. K. Ruff Inorg. Chem. 1967,6,2108. D. Zollner and A. Meuwsen 2. anorg. Chem. 1967,349 19. (a) K. K. Manredov I. G. Kerimov M. I. Mekhtiev and M. I. Veliev Russ. J . Phys. Chem., 1967 40 1655; (b) P. Cherin and P. Unger Inorg.Chem. 1967 6 1589. D. Lloyd and M. I. C. Singer Chern. Cormt 1967 390 278 A. J . Downs G. M. Sheldrick and J. J . Turner of the SeCN group with Pd has been dem~nstrated.~~' The dissociation con-stants of H,CSe have been determined [Kal = (6.9 k 0.4) x lo-,; Ka2 = (6.9 4 0.5) x The proton-donating power of H,SeO is approxi-mately 412% that of H2S04 over 50-75% (w/w) concentration range.392 Oxidation of RSeSeR by 0 gives (RSeO),O which it is deduced,393a has an Se-0-Se group in contrast to the S-S bond in analogous S compounds. Compounds R,SeO (formed from R,SeBr and Ag,O in MeOH) do not form R,Se(OH) in aqueous solution but Me,Se(OH)X (X = ClO, C1 or NO,), can be crystallised from equimolar amounts of Me,SeO and HX.393b The reaction of SeO with liquid SO gives SeSeO or (Se,03)2S02;394a the preparation of thioselenate (Se0,S-) has been firmly established.394b In HC104 H,SeO acts as a base i.r.spectra indicating the formation of Se( OH) + . 95 Evidence from vibrational spectra about the solid structure of SeCl,, SeBr, TeCl, and TeBr is contradictory some of the spectra are interpreted in terms of a molecular C, and some in terms of ionic (C,,) MX3+.396b Selenium halides in solution are only partially ionised unless the solvent has marked electron-donor properties whereas Te halides ionise as 1 1 electrolytes.397 Se vapour and F,CC:CCF react to form the hetero-cycle (50) whose structure and complexing properties are analogous to those of the corresponding S The compounds (aryl)SeCF have been ~ynthesised~~~" and the properties of the SeCF group studied.399b The considerable stability400" of the iodine complexes of cyclic selenides (CH,),SeI (n = 4 or 5) is not surprising in view of the short Se-I bond; in C,H,SSeBr, the two Br atoms are axially and the two C atoms equatorially positioned in a trigonal-bipyramidal arrangement about the Se atoms.400b Microwave spectroscopy gives the length of the Se:O bond in SeOF as 1.580 A which implies substantial (Se-0) x-b~nding.~~' Mono-fluoroselenates (Se0,F-) which are not isostructural with the fluorosulphon-" O J.L. Burmeister and H. J. Gysling Chem. Comm. 1967 543. 391 G. Gattow and M. Drager Z . anorg. Chem. 1967,349,202. '" S . Wasif J . Chem. SOC. (A) 1967 142. 393 (a) R. Paetzold S . Borek and E. Wolfram Z . anorg. Chem. 1967 353 53; (b) R.Paetzold, 394 (a) A. RPliiEka and K. DostA1 Z . Chem. 1967 7 394; (b) A. Kozhakov E. A. Buketov, '" C. Mandravel Reo. Chim. (Roumania) 1967,12 305. 396 (a) G. C. Hayward and P. J. Hendra J . Chem. Soc. (A). 1967,643 (b) J. W. George N. Katsaros. and K. J. Wynne Inorg. Chem. 1967 6 903; N. N. Greenwood. B. P. Straughan. and A. E. Wilson. J . Chem. SOC. 1966 1479; D. M. Adams and R. J. Lock ibid. 1967 145. 397 D. A. Couch P. S. Elmers J. E. Fergusson M. L. Greenfield and C. J. Wilkins J . Chern. SOC. (A) 1967,1813. 398 A. Davison and E. T. Shawl Chem. Comm. 1967 670. 399 (a) L. M. Yagupol'skii and V. G. Voloshchuk J . Gen. Chem. (U.S.S.R.) 1966 36 165; ( b ) 400 (a) J. D. McCullough and A. Brunner Inorg. Chem. 1967 6 1251 ; (b) L. Battelle C. Knobler, 401 I.C. Bowater R. D. Brown and F. R. Burden J . Mol. Spectroscopy 1967,23 272. V. Lindner G. Bochmann and P. Reich ibid. 352,295. M. I. Bakeev and A. K. Shokanov Russ. J . Inorg. Chem. 1966,11,953. V. G. Boloshchuk L. M. Yagupol'skii G. P. Syrova and V. F. Bystrov ibid. 1967,37 105. and J. D. McCullough ibid. p. 958 The Typical Elements 279 ates are obtained from SeO with alkali-metal fluorides,402a or from SeO,F, and K2Se04.402b In C,H,NO+SeOCl,- each Se atom is surrounded by one 0 atom and four C1 atoms in a distorted asymmetric square pyramid but it is not clear whether the Se is octahedrally co-ordinated (including the lone pair) or whether the structure is best represented as RH+C1-SeOC1,.403 Unlike the analogous S compounds FSe0,OR (R = Me or Et) prepared from SeO,F and (RO),SeO, are associated in the liquid state.40k Selenic acid chlorides (RSeOCl ; R = Me Et or CF,) are prepared from RSeCl and 0,; on hydrolysis CF,SeOCl gives the acid CF3Se02H.404h The previously unknown radical NSe is formed in the reaction of active nitrogen and selenium chloride.405 Two ways of preparing (51) have been reported.406 Tellurium. Disilyl telluride has been prepared.,' lb The acids TeF,(OH) -,, (n = 1-4) are stronger than Te(OH),;407 the latter forms Te(OH),,ZKF, Te(OH),,NaF and Te(OH),,l-SNH,F with the respective salts in aqueous solution and an increase in Te co-ordination is deduced.408 Vibrational spectra suggest that the Te-S bonds in [Tetu,]Cl, Tetu,Cl, and Tetu,Br (tu = thiourea) are weak.409 A detailed determination of the crystal structure of P-Me,TeI confirms the presence of [Me,Te] + and [MeTeI,] - ions.410 The vibrational spectra of various solid [TeX,I2- salts (X = C1 Br or I) are said41 la to support Urch's41 lb description of the bonding in these anions.The formation constants of the bromo-complexes of Te412" and hexachloro- and hexabromo-telluric acid4' 2b have been determined. F,TeNMe and F,Te(NMe,), the first Te(v1) derivatives with a Te-N bond are obtained from TeF and Me,NSiMe at -778O~.~l~ Group VII. -The first three volumes of a new series contain articles on various aspects of halogen chemistry.414 The chemistry of fluorides of high oxidising power has been reviewed.415 A fluoronium ion intermediate has been postu-lated in the reaction of 5-fluoro-1-pentyne with CF o C O H .~ ~ ~ Refinement 402 ( a ) A. J . Edwards M. A. Monty and R. D. Peacock J . Chem. Soc. (A) 1967,557; (b) P. Martin, 403 A. W. Cordes Inorg. Chem. 1967,6 1204. 404 (a) R. Paetzold R. Kurze and G. Engelhardt Z . anorg. Chem. 1967,353 62; (b) R. Paetzold 405 P. Goudmand and D. Dessaux J . Chim. phys. 1967,64 135. 406 L. M. Weinstock P. Davis D. M. Mulvey and J. C. Schaeffer Angew. Chem. Internat. Edn., 407 L. Kolditz and I. Fitz Z . anorg. Chem. 1967,349 175. 408 L. Kolditz and I. Fitz 2. anorg. Chem. 1967 349 184. 409 P. J. Hendra and Z . Jovic J . Chem. SOC. (A) 1967,735. 410 F. Einstein J. Trotter and C. Williston J . Chem. Soc. (A) 1967 2018. 411 ( a ) D. M. Adams and D. M. Morris J . Chem. Soc. (A) 1967 2067; (b) D. S. Urch ibid. 1964, 412 (a) G.G. Shitareva and V. A. Nazarenko Russ. J . Znorg. Chem. 1967 12 527; (b) R. Ripan 413 G. W. Fraser R. D. Peacock and P. M. Watkins Chem. Comm. 1967 1248. 414 'Halogen Chemistry' Vol. 1-3 ed. V. Gutmann Academic Press London and New York, 416 P. E. Peterson and R. J. Bopp J . Amer. Chem. Soc. 1967,89 1283. A. Scholer and E. Class Chimia (Switz.) 1967 21 162. and E. Wolfram ibid. p. 167. 1967 6 364; V. Bertini ibid. p. 563. 5775. and M. Marc Rev. Chim. (Roumania) 1967 11 1063. 1 9 p j N. I. Gubkina S. V. Sokolov and E. I. Krylov Russ. Chem. Reo. 1966 35 930 280 A. J . Downs G. M . Sheldrick and J . J. Turner of the crystal structure of I at 110"~ shows that the 1-1 bond is significantly longer (2-71 5 A) in the solid than in the gas (2.662 A); this can be correlated with a model involving four-centre six-electron bonds4' ' On the basis ofconductivity measurements on iodides in liquid iodine the self-ionisation nI s I + + I;, - has been postulated and the conduction mechanism probably involves transfer of I- to The preparation and properties of several perfluoro-acyloxy iodine compounds [I(OCOR,),] have been described.419 Many papers have been published concerning halogen or interhalogen charge-transfer species.In agreement with theory there is a larger solution-to-gas phase blue-shift in the charge-transfer band of a weak complex e.g. I,-furan 315 to 290 mp,420a than of a strong complex e.g. I,-Me,S 303 to 290 mp.420b The oxidation of Ph,N by I in propylene carbonate produces an e.s.r. spectrum assigned to theNNN'N'-tetraphenyl benzidine cation rather than [Ph3NNPh3]+ and it is concluded that in certain cases the distinction between charge-transfer formation and simple oxidation-reduction is largely academic.421 The N-I distances in the I,-phena~ine~~~" and NCI-pyridine complexes422b are 2.95 and 2.57 A respectively (cf.N-I 2.3 A in complexes of I or interhalogens with pyridine and homologues). The thermodynamic properties measured by flash spectrophotometry of the I,,,,-o-xylene com-plex in solution show it to be stronger than the I,-o-xylene complex.423 Vibrational spectra of I, Br, and IC1 charge-transfer complexes have largely confirmed theoretical predictions,42h and indicated a slight modification of the structure of the solid Br,-benzene complex.424b A U.V.spectral study of I,-valeronitrile in n-hexane results in a warning about indiscriminate use of Taft cr* values for predicting equilibrium constant variation with substitu-t i ~ n . ~ ~ The complexes of I and 'ICl with aromatic a m i n e ~ ~ ~ ~ " and I,-alkyl s ~ l p h i d e ~ ~ ~ ' have been investigated by n.m.r. 1.r. spectra support the n.m.r. results that the hydrogen atoms in H,F,- are not mid-way between the fluorine Vibrational spectra of BrHBr -and BrDBr- indicate that the symmetry of the ion is dependent on environ-F. van Bolhuis P. B. Koster and T. Migchelson. Acta Cryst. 1967 23 90. 5 1 7 418 D. J. Bearcroft and N. H. Nachtrieb J . Phys. Chem. 1967,71,316. 419 M. Schmeisser K. Dahmen and P. Sartori Chem. Ber. 1967,100 1633. 420 (a) E. I.Ginns and R. L. Strong J . Phys. Chem. 1967 71 3059; (b) M. Tamres and J. M. 421 W. H. Bruning R. F. Nelson L. S. Marcoux and R. N. Adams J . Phys. Chem. 1967,71,3055. 422 (a) T. Uchida Bull. Chem. SOC. Japan 1967,40, 2244; (b) T. Dahl 0. Hassel and K. Sky Acta 423 R. L. Strong and J. Perano J . Amer. Chem. SOC. 1967,89 2535. 424 (a) R. F. Lake and H. W. Thompson Proc. Roy. SOC. 1967 A 297,440; P. Klaboe J . Amer. Chem. SOC. 1967 89 3667; I. Haque and J. L. Wood Spectrochim. Acta 1967 23A 959 2523; J. Gerbier and V. Lorenzelli ibid. p. 1469; F. Watari ibid. p. 1917; Y . Yagi A. I. Popov and W. B. Person J . Phys. Chem. 1967 71 2439; (b) W. B. Person C. F. Cook and H. B. Friedrich J . Chem. Phys. 1967,46,2521. Goodenow ibid. p. 1982. Chem. Scand. 1967,21,592. 425 J.A. Maguire A. Bramley and J. J. Banewicz Inorg. Chem. 1967,6 1752. 426 (a) J. Yarwood Chem. Comm. 1967 809; (b) E. T. Strom W. L. Orr B. S. Snowden jun. and D. E. Woessner J . Phys. Chem. 1967,71,4017. 427 (a) A. AZman A. Ocvirk D. Hadii P. A. Gigukre and M. Schneider Canad. J . Chem. 1967, 45 1347; (b) J. C. Evans and G. Y-S. Lo J . Phys. Chem. 1967,71 3942; ( c ) J. W. Nibler and G. C. Pimentel J . Chem. Phys. 1967.47 710 The Typical Elements 28 1 ment as in the case of C1HC1-.427b By using a special low-temperature tech-nique i.r. spectra of various Cs+XHY- salts have been obtained and the bending vibration (v2) of the anions reassigned at about one half the previously accepted values ; the high intensity of the 2v2 (previously v2) band in ClHCl -is ascribed to the asymmetry of the hydrogen-bond potential function.427c Further n.q.r.studies support the asymmetry of ClHCl- in the Me,N+ salt (one signal at 20 Mc./sec. and one not observed probably below 10 Mc./se~.)~"' but suggest that the anion is symmetrical in the Et,N+ salt (one signal at 12 M c . / s e ~ . ) . ~ ~ ~ ' Conductimetric potentiometric and kinetic studies on aqueous iodic acid give a value of 4 1. mole-' for the stability constant of H(I03)2- and provide no evidence for the formation of 10,' 42g The radical Cl has been detected by i.r. spectroscopy of the condensate (20%) from a Kr-Cl gas mixture subjected to a microwave discharge; the force constants suggest that removing a non-bonding electron from C1 - has little effect on the bond strength.430 The chemistry of interhalogen compounds has been reviewed.431 Pure ClF can be obtained from the reaction of F with MClF (M = K or Cs) ; n.m.r.spectra indicate a square-pyramidal and equilibrium studies give AHf (800% and 298"~) = -56.0 and -57.7 kcal.mole- respectively.432b9 The specific conductance of IF is extremely low ohm-' cm.-l) and it forms no complexes with CsF.,,,' Equilibrium studies on the 1 1 adduct IF,,AsF give AH = 43.9 kcal.mole-' for the reac-tion adduct(s) + IF,(g) + AsF,(g); powder photography and vibrational spectra indicate an ionic structure for the adduct and that the IF6+ ion is octahedral the magnitude of the I-F stretching force constant being best interpreted via an sp3d2 hybridisation bonding scheme.433b X-Ray work on BrF,,SbF shows that the solid consists of BrF,+ ions bound by two weak F bridges to adjacent SbF,- ions the Br atom and its four surrounding F atoms being in the same plane.,, The frequency assignment of C1F2+ has been revised Raman spectra support the linearity of C1F,-.435b It is not possible to assign the vibrational spectra of MBrICl (M = Cs Rb or Me,N) without making the I-Br force-constant greater than the I-Cl force-constant and it is concluded that M+BrICl- is actually a mixed crystal of M'IC1,-and M+IBr2-.436u However X-ray work on the disordered NH,BrICl is 428 (a) T.E. Haas and S. M. Welsh J . Phys. Chem. 1967,71,3363; (6) J . C. Evans and G. Y-S. Lo, 429 A. D. Pethybridge and J. E. Prue Trans. Faruday Soc. 1967,63,2019. 430 L. Y. Nelson and G. C. Pimentel J. Chem.Phys. 1967,47 3671. 431 H. Meinert 2. Chem. 1967,7,41. 432 (a) D. Pilipovich W. Maya E. A. Lawton H. F. Bauer D. F. Sheehan N. N. Ogimachi R. D. Wilson F. C. Grunderloy jun. and V. E. Bedwell Inorg. Chem. 1967 6 1918; (b) H. F. Bauer and D. F. Sheehan ibid. p. 1736; (c) R. Bougon J. Chatelet and P. Plurien Compt. rend. 1967,264 C 1747. 433 (a) H. Selig C. W. Williams and G. J. Moody J . Phys. Chem. 1967,71,2739; (b) K. 0. Christe and W. Sawodny Inorg. Chem. 1967,6,1783. 434 A. J. Edwards and G. R. Jones Chem. Comm. 1967 1304. 435 (a) K. 0. Christe and W. Sawodny Znorg. Chem. 1967 6 313; (b) K. 0. Christe W. Sawodny, and J. P. Guertin Inorg. Chem. 1967,6 1159. 436 (a) A. G. Maki and R. Forneris Spectrochim. Acta 1967 23A 867; (b) T. Migchelson and A. Vos Acta Cryst.1967 22 812; (c) G. C. Hayward and P. J. Hendra Spectrochim. Acta 1967, 23A 2309. ibid. p. 3697 282 A. J. Downs G . M . Sheliirick and J. J . Turner best interpreted on the basis of BrICl- ions with I-Cl (2.91 A) longer than Br-I (2.51 A).436b Force constants of interhalide ions support wholly three-centre p - b ~ n d i n g . ~ ~ ~ " . Preliminary vibrational spectra of 12Cl - and 12C12Br- indicate that these ions may have a V-structure similar to I,-.437 There are two structural modifications of (Et,N)I, one with symmetric and the other with asymmetric I,- ions ;438 this invalidates the theory correlating I,- structure and cation size. Y. Yagi and A. I. Popov J . Inorg. Nuclear Chem. 1967,29,2223. *38 T. Migchelson and A. Vos Acta Cryst. 1967,23 796. 439 Note added in proof BrO,- has been prepared E. H. Appelman J . Amer. Chem. SOC. 1968, 90,1900

ISSN:0069-3022    

DOI:10.1039/GR9676400219

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

12. THE TRANSITION ELEMENTS By A. B. Blake J. R. Chippefield P. G. Nelson and C. F. Stoneman (Department of Chemistry The University Hull) A plant that produced much foliage but little fruit such was transition-metal chemistry in 1967. There may have been much lateral movement but there was very little forward progress. Indeed much of the work done was presented without any explicit reason for doing it. This makes it very difficult to follow the policy of Annual Reports i.e. ‘to publish reasonably complete accounts of highly significant material’,’ and still have a report. Added to this is the problem of doing justice to work done in the poorly systematised areas where signifi-cance is not obvious. We have therefore adopted the procedure of choosing (highly subjectively) some four hundred references to write on and of leaving such areas as metallic compounds multiple oxides solvent extraction and equilibria in solution with only a mention.This report is integral with the following one the distinction between them is that this one is concerned with compounds other than those containing M-H M-B M - C etc. M-P etc. M-M’ M-N2 M-NO and M-O2 bonds but including oxygen and halogen clusters peroxides and perhaps mistakenly cyanides. This division is more intuitive than reasoned ; it corres-ponds roughly to whatever is the distinction between K,FeF and CSH,Fe(CO),. In this report the metals are dealt with group by group as usual but complexes where the ligands are of prime interest are treated separately afterwards along with peroxides and cyanides.In addition topics that have attracted particular attention during the year t i . clusters complexes of ligands of uncertain oxidation number (Jsrgensen’s ‘suspect’ ligands) five-co-ordination high co-ordination numbers optical stereochemistry systems of biological interest and contact shifts are (except the first two) dealt with under the heading Special Topics. There is also a brief section on Electronic Properties to sum up progress in this area. Proliferation of papers has brought with it proliferation of reviews. General reviews include photochemistry of transition-metal complexes,2 electronic properties of binary compounds of the metals of the first ~ e r i e s ~ siloxanes of the transition metals i.e. compounds containing the M-0-Si gro~ping,~ liquid-liquid extraction of metal ions,’ nitrides of metals of the first series,6 ’ Chem.in Britain 1967 151. E. L. Wehry Quart. Rev. 1967 21 213. A. T. Howe and P. J. Fensham Quart. Rev. 1967,21 507. ‘ F. Schindler and H. Schmidbauer Angew. Chem. Internat. Edn. 1967,6 683. 5 D. F. Peppard Ado. Inorg. Chem. Radiochem. 1966,9 1. I’ R. Juza Ado. Inorg. Chem. Radiochem 1966.9 81 284 A. B. Blake J . R. Chipperfield P . G. Nelson and C. F . Stoneman equilibria of complexes in non-aqueous ~olvents.~ A book of reviews and papers on co-ordination chemistry has been dedicated to the memory of Alfred Werner (born 12th December 1866).8 Other reviews are mentioned at appropriate points in the report. Nomenclature. A usage has been devised in an attempt to increase the readability of the report metals under consideration are denoted by M, cations by A anions by X neutral ligands by L and radicals by R; positive oxidation numbers greater than + 1 are indicated by capital Roman numerals and negative ones less than - 1 are indicated by lower case Roman numerals; the ‘denticities’ of multidentate ligands are indicated by Latin numerical prefixes thus e.g.compounds of the type exemplified by [TiCl,(CH =CO*CH*CO-CH3),] can all be represented by [TiX,(biX),]. The usual abbreviations are used for ethylenediamine (en) propylenediamine (pn) triethylenetetramine (trien) pyridine (py) 2,2’-bipyridyl (bipy) terpyridyl (terpy) 1,lO-p henanthroline (phen) 0-p henylenebis(dimet hylarsine) (diars), acetylacetonate (acac) and oxalate (ox).The Rare Earths.-A vast amount of work has been published on the rare earths (the lanthanides and the elements of the scandium group) particularly on their salts and complexes in Russian Journal oflnorganic Chemistry and on the electronic spectra of their compounds in the Journal of Chemical Physics. Reviews have been published in Progress in the Science and Tech-nology ofthe Rare Earths and a book on their complexes has been written.’ The picture that continues to emerge is (a) the formation of compound types which sometimes prevail for the whole series of lanthanides e.g. [M(N03)3(EtOH)(Ph3M’O)2] [M(C,F *CO*CH-CO*CMe,),] 0 and 1H20 and [M(N03)3(4,4‘-N2C10H6B~~)2] (M’ = P or As; N2CloHs = bipy),”. but which sometimes change along the series e.g. MCl bipy,,nH,O gives way to MCl,bipy,n’H,O for elements following holmium despite identical preparative conditions ;I2 and (b) variable stereochemistry and high co-ordina-tion numbers illustrated by the new form of eight-co-ordination found in Cs[Y(CF CO CH CO CF,),] and NH,[Pr(2-SC,H3 CO CH CO *CF,),],H20 (uiz.D dodecahedral to be added to D,, dodecahedral and D, antipris-matic already known),’ and by the nine-co-ordinate M(H,O) + ions which ’ L. 1. Katzin Transition Metal Chem. 1966 3 56. ‘Werner Centennial’. Advances in Chemistry Series No. 62 1967. S. P. Sinha ‘Complexes of the Rare Earths,’ Pergamon Press Oxford 1966. lo D. R. Cousins and F. A. Hart J. Znorg. Nuclear Chem. 1967,29,1745,2965; C. S. Springer,jun, D. W. Meek and R. E. Sievers Inorg. Chem. 1967,6,1105.F. A. Hart J. E. Newbery and D. Shaw Chem. Comm. 1967,45. I t N. I. Lobanov and V. A. Smirnova Rum. J . Inorg. Chem. 1967,12,243. l 3 S. J. Lippard F. A. Cotton and P. Legzdins J . Amer. Chem. Soc. 1966,88 5930; R. A. Lalan-cette M. Cefola W. C. Hamilton and S. J. La Placa Znorg. Chem. 1967,6 2127 The Transition Elements 285 are presumably present in the lanthanide bromates M(Br0,),,9H20 in view of their isomorphism with Nd(Br03)3,9Hz0.'4 All this is with the exclusion of promethium but more of its chemistry has been established" and the ionic radius of Pm3+ found to lie between those of Nd3+ and Sm3+. The study of the electronic spectra of lanthanide compounds follows the corresponding studies for transition-metal compounds besides the fitting of observed spectra to the formulae of crystal-field theory stereochemical criteria are being sought from the more sensitive bands,I6 and attempts are being made to calculate the splittings theoretically ;17 these calculations and contact-shift measurements," suggest that covalent interactions between 4f electrons and ligands are small.The first measurements of a Cotton effect withfelectrons have been published." Apart perhaps from the demonstration of the increasing acidity of the lanthanide hydroxides with increase in atomic numberlg (paralleling the decreasing basicity) and the reports of compounds of the type M,M'C with the perovskite structure (M' = Al Sn etc.),20 little of more specific significance has appeared. In particular progress in the chemistry of oxidation states other than + 3 has abated.However the preparation of air-stable EuC204,H20, isomorphous with SrCZO4,H2O and possibly a better starting material for Eu" compounds than E U C ~ ~ ~ is worth metntioning and the curious phase transformation in EuTe SmTe and presumably YbTe which does not involve a change of structure (NaCl) high pressure reversibly converts the more salt-like form into the metallic form of the other lanthanides and reduces the cell constant by about 5 % to bring it in line with the others.22 The Actinides.-The preparation of actinide and the co-ordination chemistry of actinide halides24 have been reviewed. An isotope of mendelevium 2s8Md with a remarkably long half-life of about two months has been reported; this not only makes possible a full investigation of the chemistry of this element but also encourages the belief that longer-lived isotopes will be found among the heavier elements.2s As striking are the reports of a dipositive state of Cf Es Fm and Md in aqueous solution based on inter a2ia the observation that these metals like Sm Eu, and Yb are extracted in preference to other members of the series when l4 I.Mayer and Y. Glasner J . Inorg. Nuclear Chem. 1967,29 1605. I s V. Scherer Nuclear Sci. Abstracts 1966. 20 4979. l6 D. G. Karraker Inorg. Chem. 1967,6 1863. '' R. E. Watson and A. J. Freeman Phys. Rev. 1967,156 251; M. M. Ellis and D. J. Newman, J . Chem Phys. 1967,47,1986. S. Kida T. Isobe and S. Misumi Bull. Chem. SOC. Japan 1966,39 2786. B. N. Ivanov-Emin E. N. Siforova Marianna Mekes Fisher and V.Mel'yado Kampos, Russ. J . Inorg. Chem. 1966 11 258; B. N. Ivanov-Emin E. N. Siforova V. Mel'yado Kampos and E. Balestr Lafert ibid. p. 1054. 2o H. Haschke H. Nowotny and F. Benesovsky Monatsh. 1966,97 716; 1967,98 273. " H. Pink Z. anorg. Chem. 1967,353,247. '' C. J. M. Rooymans Berichte Bunsengesellschaft Phys. Chem. 1966,70 1036. 23 B. B. Cunningham Preparative Inorg. Reactions 1966 3 79. " K. W. Bagnall Co-ordination Chem Rev. 1967,2 145. " New Scientist 1967,35 598 286 A. B. Blake J . R. Chipperfield P. G. Nelson and C . F. Stoneman aqueous solutions containing their M3 + ions are treated with sodium amalgam, and on the preferential precipitation of Md rather than Es when such solutions are treated with milder reducing agents and then barium sulphateis precipitated : the standard potential of M3+ + e- = M2+ may be as positive as - 0 .1 ~ for Md (Md3 + is even reduced by Eu2 +) with that for Es at least l v more negative.26 On the other hand attempts to oxidise Cm"' and C?" in 12-15~-CsF with Na,Xe06 were unsuccessf~l.~ Much of the simple chemistry of the less available actinides remains to be worked out. The stage reached with the various elements can be judged from the latest developments given in this report. The chemistry of the protactinium halides has reached a relatively advanced stage all the tetrapositive chlorides, bromides and iodides of the types Pax, PaOX, and A,PaX are now known28 together with PaF and its derivatives APaF, A4PaF8 or A,Pa,F, depending on A;29 and all the pentapositive chlorides bromides and iodides of the types Pax, PaOX, PaO,X and APaX are now known,,' in addition to PaF and its derivatives.Though no signs of Pal were observed during the work on PaI,,,' it is claimed that this may be formed by thermal de-composition of PaI,;,' if so it is the first formally tripositive protactinium compound. The first solid compound of hexapositive americium has been obtained ethanol precipitates from a solution of AmV and CsCl in dilute hydrochloric acid a pale green compound analysed as Cs8(Am0,),C1 and isostructural with the compound previously formulated as Cs3Np02C1 ; it is oxidised by concentrated hydrochloric acid to red C S ~ A ~ O C ~ . ~ ~ The series of compounds of the types K,M,F, and Rb2MF6 have been extended to curium;, further X-ray studies of berkelium compounds and the first such studies of californium compounds have been made viz.of Bk,O,. BkOCI, BkO, Cf203 CfOCl and CfCl ;34 and enough einsteinium has been obtained for a measurement of the visible absorption spectrum of Es'" in hydrochloric acid. Most of the compounds mentioned are isostructural with corresponding compounds of other actinides and several long series now exist displaying the actinide contraction.33* 34 An exception is PaCl which contains pentagonal 26 J. Maly Znorg. Nuclear Chem Letters 1967 3 373; J. Mali and B. B. Cunningham ibid., " H. P. Holcomb J . Znorg. Nuclear Chem. 1967,29 2885. '* D. Brown and P. J. Jones J . Chem SOC. (A) 1967 pp. 243,719. '' L. B. Asprey F H. Kruse and R. A. Penneman Znorg.Chem. 1967,6 544. " D. Brown and P. J. Jones J . Chem SOC. (A) 1967,247; D. Brown J. F. Easey and P. J. Jones, 31 V. Scherer F. Weigel and M. Van Ghemen Inorg. Nuclear Chem Letters 1967 3 589. 32 K. W. Bagnall J. B. Laidler and M. k A. Stewart Chem. Comm. 1967 24. 3 3 T. K. Keenan Znorg. Nuclear Chem Letters 1967 3 391 463. 34 J. R. Peterson and B. B. Cunningham Znorg. Nuclear Chem Letters 1967 3 327 579; J. L. " B. B. Cunningham J. R Peterson R. D. Baybarz and T. C. Parsons Znorg. Nuclear Chem. p. 445. ibid. p. 1698. Green and B. B. Cunningham ibid. p. 343. Letters 1967,3 519 The Transition Elements 287 bipyramidal units like PaF and P-UF, whereas UCl contains octahedral units like WUF,.~, Work on the more available elements has done little more than reinforce the general picture of (a) multivarious stereochemistry and (b) differing oxidation-reduction behaviour.(a) is well illustrated in a review of the co-ordination possibilities of thorium37 and it is further supported by reports of an eight-co-ordinate cation [Th((Me,N),PO *O OP(NMe2)2}4]4’ and ten-co-ordinate compounds [Th(2-SC,H3 *CO-CH*CO*CF,),(biL)] o f t h o r i ~ m ” ~ ~ ~ by evidence for higher co-ordination numbers of U”’ and U”’ in molten fluorides than in molten chloride^,^' and by further examples of the-ability of UO,,’ to be four- five- or six-co-ordinate in the perpendicular plane uiz. [UO,(AcO),(H,O)I and [Uo2(NC9H6 .0)2(NC9H6.0H)],CHC13 (NC9H6-OH = 8-hydroxyquinoline) where it is five-41 and [UO ((Me2N)2PO*O*OP(NMe,),) 3]2’ where it may be six-~o-ordinate.~~ Illustrations of (b) are the failure of Np(OR), to oxidise to NP(OR)~ in the way that U(OR) oxidises to U(OR),,42 and the disproportionation of pink CSNpF in liquid hydrogen fluoride into green NpF and orange NpF whereas blue CsUF only dissolves43 (the exact opposite of the situation in water where UO + disproportionates and NpO + does not).The determination of stability constants by Donnan membrane equilibrium has been introduced44 with a study of sulphate complexes of UOZ2+. The Titanium Group.-Titanium. The controversy over the existence of titanyl (TiO”) compounds has continued; doubts have been cast on the existence of this moiety in TiOacac and A2TiOCl4?’ and no spectroscopic evidence could be found for it in but it has been claimed to be present as such in TiO[TiF6] and the new compound TiO[SbF,] on the basis of far4.r.spectra.47 The structure of the large group of compounds G. S. Smith Q. Johnson and R. E. Elson Acta Cryst. 1967,22,300; R. P. Dodge G. S. Smith, Q. Johnson and R. E. Elson ibid. p. 85. 37 A. K. Molodkin and 0. M. Ivanova Russ. J . Znorg. Chem. 1966 11 1318. ’* M. D. Joesten Znorg. Chem. 1967,6 1598. ’ 9 E. Butter Z . Chern. 1967,7 199. *’ J. P. Young Znorg. Chem. 1967,6 1486. *’ E. Frasson G. Bombieri and C. Panattoni Co-ordination Chem. Rev. 1966 1 145; D. Hall, ** E. T. Samulski and D. G. Karraker J . Znorg. Nuclear Chem. 1967,29,993. *’ L. B. Asprey and R. A. Penneman J . Amer. Chem. SOC. 1967,89 172. ** R. M. Wallace J . Phys. Chern. 1967,71 1271. *’ I. R. Beattie and V.Fawcett J . Chern. SOC. (A) 1967 1583. *‘ W. P. Griffith and T. D. Wickins J . Chem. SOC. ( A ) 1967 675. 47 K. Dehnicke and J. Weidlein Angew. Chem. Internat. Edn. 1966 5 1041; J. Weidlein and K Dehnicke. Z onorq Chem 1966. -348. 278. A. D. Rae and T. N. Waters Acta Cryst. 1967,22,258. 288 A. B. Blake J . R. Chipperfield P . G. Nelson and C. F . Stoneman of the type [TiX,(biX),] has attracted attention;48 the conclusion is that many if not all of them are cis and perhaps that X-ray crystallography is more reliable than i.r. spectroscopy though an attempt to determine the crystal structure of TiCl,acac yielded that of Ti20C12acac,,CHC13~9 which is also octahedral (a less quickly noticed example of this” provides a salutory reminder that crystal structure determinations are not infallible).There have been attempts to make Ti(OAc) and Ti(SR), but the products contained extraneous m~lecules.’~ Crystalline Ti(HP0,),,H20 titanium hexacyanoferrate(n) and a chromium triphosphate have been shown to be promising ion-exchange materials for the separation (from each other or from other ions) of the alkali metals.’, The chemistry of tripositive titanium has been further shown to be very like that of tripositive vanadium and chromium (except for ease of oxidation) : isomorphous compounds of the types [M(biL),]Cl (biL = en or pn) and A,[MX,] (X = Cl Br or NCSe) are now known for M = Ti V and in most cases Cr which are within each series isomorphous as far as is known; but (Et,N) TiC1 does not appear to contain tetrahedral MCl,- as does (P~,As)VC~,.’~* 54 The salts TiC1,,6H20 and TiBr,,6H20 have been formu-lated as trans-[TiX2(H20),]X,2H20 on the basis of their electronic and vibra-tional spectra.’ More dipositive titanium complexes have been prepared of the types [TiX2L2] and [TiX,(biL)] (X = C1 or Br); they appear to be poly-meric.’ ’ Zirconium and hafnium. A13+ is reported to precipitate hafnium from an acidic solution of hafnium and zirconium complex oxalates by selective decomplexing.’ As with titanium the debate about the existence of the M02+ moieties continues; no spectroscopic evidence could be found for them in but the far-i.r. spectrum of ZrOCl is said to support the formulation [ZrO] [ZrOC14].47 Raman i.r. and “F n.m.r. studies show that MF,’ - ions are present in hydrofluoric acid solutions of all three elements in the tetra-positive state;46*” the only possible sign of MFT2- was the more rapid 48 I.Douek M. J. Frazer Z . Goffer M. Goldstein B. Rimmer and H. A. Willis Spectrochim. Act4 1967,23 A 373 ; R. C. Fay and R. N. Lowry Inorg. Nuclear Chem. Letters. 1967,3,117; R. C. Fay and R. N. Lowry Znorg. Chem. 1967,6,1512; N. Serpone and R. C. Fay ibid. p. 1835; A. G. Swallow and B. F. Studd Chem. Comm. 1967 1197. 49 K. Watenpaugh and C. N. Caughlan Znorg. Chem. 1967,6,963. so J. L. Hoard G. H. Cohen and M. D. Glick J . Amer. Chem SOC. 1967,89 1992. K. H. Gayer S. F. Pavkovic and G. J. Tennenhouse 2. anorg. Chem. 1967 354 74; D. C. Bradley and P. A. Hammersley J . Chem. SOC. (A) 1967 1894. ’’ G. Albert& P. Cardini-Galli U.Costantino and E. Torracca J . Znorg. Nucleur Chem. 1967, 29 571 ; K. H. Lieser J. Bastian A. B. H. Hecker and W. Hild ibid. p. 815; D. Betteridge and G. N. Stradling ibid. p. 2652. s3 R. J. H. Clark and M. L. Greenfield J. Chem. SOC. (A) 1967 409. s4 G. W. A. Fowles and B. J. Russ J . Chem SOC. (A) 1967,517; J. L. Burmeister and L. E. Williams, ” (a) H. L. Schlafer and H. P. Fritz Spectrochirn. Acta 1967,23 A 1409; (b) G. W. A. Fowles and s6 Sw. Pajakoff Mikrochim Acta 1966 751. ” P. A. W. Dean and D. F. Evans J . Chem. SOC. (A) 1967,698. J . Znorg. Nuclear Chem. 1967,29 839. T. E. Lester Chem. Comm. 1967,47 The Transition Elements 289 fluorine exchange in the case of zirconium and hafnium.57 X-Ray studies reveal that Cu2ZrF,,12H,0 and Cu3Zr2F14,16H20 contain square anti-prismatic ZrFs4- units like TaF,,- (sharing an edge in the latter compound)58 and Zr(BH,) at - 160" contains twelve-co-ordinate z i r ~ o n i u m .~ ~ We have come to expect diversity of stereochemical behaviour with these elements. The first Zr"' complexes (if the trihalides are not complexes) have been made from ZrX (X = C1 Br or I) and nitrogen ligands; their stoicheio-metries are various and all have magnetic moments at room temperature well below the spin-only value.60 The Vanadium Group.- Vanadium. The co-ordination chemistry of vanadium in general6'" and of the V02+ ion in particular61b has been reviewed. The small number of dipositive vanadium complexes has been increased by the preparation of three complexes of the type [V(R*CO*CH*CO* R ) P ~ ] ~ ~ while the synthesis of several complexes of the types [V(biL),]X and [VX,(biL),]X' raises the small number of cationic complexes of tripositive vanadium.53* 63 E.s.r.measurements of oxides with compositions between V 2 0 3 and V 2 0 5 are apparently best i n t e r ~ r e t e d ~ ~ in terms of the coexistence of V3+ and V5+ with no V4+. The chemistry of the V02+ ion continues to command atten-tion.61h More work has been published supporting the view that the water molecule opposite the oxygen in [VO(H20)5]2+ is less strongly bound than the other four.65 More interesting approximately trigonal bipyramidal co-ordination with the vanadyl oxygen atom in the equatorial plane has been found for the [VOta~?l,~- ion where H,tart = H0,C-[CH(OH)], and is said to be present in one of the several new complexes of the type VOX2L2,67*68 uiz.[VOCl,(Me,N),] isostructural with [VC13(Me,N)2]67 (note that [VO(acac),] could be described as distorted trigonal bipyramidal instead of distorted square planar.)67 This perplexing stereochemical picture is completed by [VO(NO,),] which contains seven-co-ordinate vanadium if the nitrate groups are bidentate as ~laimed.~' 5 8 J. Fischer and R. Weiss Chem. Comm. 1967 328; J. Fischer R. Elchinger and R. Weiss, 5 9 P. H. Bird and M. R. Churchill Chem. Comm. 1967,403. 6o G. W. A. Fowles. B. J. Russ and G. R. Willey. Chem. Comm 1967 646. 62 Y. Torii H. Iwaki and Y. Inamura h l l . Chem. SOC. Japan 1967,40 1550. 63 G. W. A. Fowles and P. T. Greene J. Chem. SOC. (A) 1967 1869. 64 Ss.M. Arija S. Ch. Akopjan and W. Wintruff 2. anorg. Chem. 1967,352 102. 6 5 W. B. Lewis Inorg. Chem. 1967,6 1737; cf. J. Reuben and D. Fiat ibid. p. 579. 66 R. E. Tapscott and R. L. Belford Inorg. Chem. 1967 6 735; J. G. Forrest and C. K. Prout, '' K. L. Baker D. A. Edwards G. W. A. Fowles and R. G. Williams J. Inorg. Nuclear Chem., R. G. Garvey and R. 0. Ragsdale J . Inorg. Nuclear Chem. 1967 29 745; J. G. H. du Preez ibid. p. 329. (a) D. Nicholls Co-ordinarion Chem. Rev. 1966. 1. 379; ( h ) J. Selbin ihitl p. 293. J . Chem. SOC. (A) 1967 1312. 1967,29 1881. and F. G. Sadie Inorg. Chim. Actu 1967 1 202. 69 C. C. Addison D. W. Amos D. Sutton and W. H. H. Hoyle J . Chem. SOC. (A) 1967 808 290 A. B. Blake J . R. Chipperfield P . G. Nelson and C . F . Stoneman Far-i.r.spectral evidence has been given for the existence of the V02+ ion as such in the new compounds V 0 2 F and V02[SbF6] though not in V02Cl,4' and at least as a moiety in V0210,,2H20.70 Perhaps surprisingly VF is a weak acid in liquid hydrogen fluoride ;71 more surprisingly it gives with MF3 (M = P As or Sb) materials provisionally formulated as VF3+MF6-with polymeric VF3+ which are also preparable from VF and MF,.72 The six-co-ordination of vanadium in solid VO(OMe) is as usual irreg~lar.'~ Niobium and tantalum. As last year some attention has been given to clusters of these elcrnents. The three clusters (&X12)"+ (n = 2 3 or 4) previously known for M,X = Ta,Cl are now all known for Nb,Cl and Ta,Br; in particular, Nb6Cl1 s ~ H ~ O isomorphous with Ta,Cl s ~ H ~ O hydrated Ta6Brl and improved synthesis of Nb6C1,,,8H20) have been prepared as well as com-pounds formulated as [(Nb6Cl12)C1&,] ; they are diamagnetic for n = 2 or 4 and paramagnetic for n = 3.74 Serious doubts have been cast on the existence of all the reported lower oxides of tantalum except TaO (x = ca.2.4) including even Ta02.75 The purple compounds Cs2MC1 have the K2PtC16 structure76 and so contain octahedral MC162 - ions. The difficult problem of the species present in solutions of pentapositive niobium and tantalum continues to elicit response :77 further evidence that hydroxide-bridged species predominate in perchloric acid NbOFS2 - and TaF6- with TaF72- in hydrofluoric acid NbOClS2- and TaC1,- in strong hydrochloric and HnM6019(8 -"I- in alkali78 has been presented.The first thiocyanate complexes of these two elements have been made including deep blue KNb(NCS)6 and oFange KTa(NCS)6.79 The Chromium Group.-Chromium. A review has appeared on the chemistry of tripositive chromium in aqueous solution.80 The little new work that as been published of specific significance to chromium relates to the stereochemistry of chromium(I1). If the high-temperature form of KCrF has the cubic perovskite structure 81 the average Ta6Br16 and compounds Of the type AnNb6C118 (including K4NbsC118 in an 7 0 G. Ladwig Z . anorg. Chem. 1967,353 311. 71 H. Selig and B. Frlec J . Znorg. Nuclear Chem. 1967 29 1887. 72 J. H. Canterford and T. A. O'Donnell Znorg. Chem. 1967,6 541. 7 3 C. N. Caughlan H. M. Smith and K.Watenpaugh Inorg. Chem. 1966,5 2131. B. Spreckelmeyer and H. Schlfer J . Less-Common Metals 1967. 13 122. 127 P. B. Fleming, T. A. Dougherty and R. E. McCarley J . Amer. Chem. SOC. 1967 89 159; R. A. Mackay and R. F. Schneider Znorg. Chem. 1967 6 549; P. B. Fleming L. A. Mueller and R. E. McCarley ibid. p. 1; R. A. Field and D. L. Kepert J. Less-Common Metals 1967 13 378. 75 D. R. Kudrak and M. J. Sienko Znorg. Chem. 1967,6,880. 7 6 I. S. Morozov and N. P. Lipatova Russ. J. Znorg. Chem. 1966 11 550; E. K. Smirnova and I. V. Vasil'kova ibid. 1967 12 292; S. M. Homer F. N. Collier jun. and S. Y. Tyree jun. J . Less-Common Metals 1967,13 85. 74 77 E. Lassner and R. Puschel J . Less-Common Metals 1967 12 146. 79 T. M. Brown and G. F. Knox J . Amer. Chem. SOC. 1967,89,5296; H.Bochland and E. Tiede, F. W. Smith J. Znorg. Nuclear Chem. 1967,29 1161. J . Less-Common Metals 1967 13,224. J. E. Earley and R. D. Cannon Transition Metal Chem. 1965,1 34. J.-C. Cousseins and A. de Kozak Compt. rend. 1966,263 C 1533 The Transition Elements 29 1 environment of the Cr" must be undistorted octahedral. The new form of chromium(I1) phthalocyanine isomorphous with the dipositive phthalo-cyanines of other metals of the first-transition series,82 must contain square-planar Cr". Two of the chromium(r1) complexes with Ph3P0 or Ph,AsO are tetrahedral rather than tetragonally distorted octahedral viz. the yellow (as opposed to the green) form of CrBr,(Ph,PO) and Cr12(Ph3P0)2.83 The increasing interest in the photochemistry of transition-metal complexes2 is exemplified by the study of the aquation of the [Cr(NCS)(NH,),]" ion in which it was found that thermal aquation yielded more [Cr(H20)(NH3)5]3 + but photochemical aquation more [Cr(NCS)(H20)(NH3),]* + showing that the excited states of complexes have different chemistries from the ground states (as is well known for simpler systems).84 Molybdenum and tungsten.Reviews have been written on the electrochemical properties of these metals,85 the co-ordination compounds of molybdenum,86 and the inorganic chemistry of tungsten.87 There have been some interesting developments in the field of molybdenum and tungsten clusters. A variety of six-co-ordinate complexes of the ( M O ~ C ~ ~ ) ~ ' ion have been prepared including one [(Mo,C18)12 bipy,]I, in which six (rather than the usual four) halogens react when it is titrated with silver nitrate.88 A new chloride of tungsten WCl, has been prepared from the dichloride (w&18)c14 and shown89 to be (w&112)c16 with a cluster of the same structure as (Nb6C112)2+.The product of the reaction between K,W2C19 and pyridine has been shown to be W2C1,py and not W2C16py3 and so may contain a double rather than a triple bridge.g0 A new type of cluster containing three molybdenum atoms may be present in compounds thought to contain the ions [Mo,X,,]~- [Mo3Cll2I6- and [Mo3Xl1I5- (X = C1 or Br).91 A considerable amount of work has been done on the halides of molybdenum and tungsten. Most interesting is the preparation of molybdenum hexa-chloride by refluxing molybdenum trioxide with thionyl chloride for several hours ; it is a black powder isostructural with WC16.92 Spectroscopic magnetic, and X-ray measurements have now established that tungsten pentachloride has a dimeric structure like Mo2C1,, instead of the previously suggested 82 C.Ercolani Ricerca sci. 1966,36,975. 83 D. E. Scaife Austral. J . Chem. 1967 20 845; L. F. Larkworthy and D. J. Phillips J . Inorg. 84 R. D. Lindholm E. Zinato and A. W. Adamson J . Phys. Chem. 1967,71,3713. E F Sperenskaya V. E. Mertsalova. and I. I. Kulev. RUPF Chem Rev 1966. 35. 897. 86 P. C. H. Mitchell Co-ordination Chem. Rev. 1966 1 315. R. V. Parish Adv. Znorg. Chem. Radiochem. 1966,9 315. J. E. Fergusson B. H. Robinson and C. J. Wilkins E Chem. SOC. (A) 1967 486. 89 R. Siepmann H.-G.von Schnering and H. Schiifer Angew. Chem. Internat. Edn. 1967,6,637. 90 R. Saillant J. L. Hayden and R. A. D. Wentworth Znorg. Chem. 1967,6 1497. 91 G. B. Allison I. R. Anderson and J. C. Sheldon Austral. J . Chem. 1967 20 869. 92 M. Mercer Chem. Comm. 1967 119. Nuclear Chem. 1967,29,2101 292 A. B. Blake J . R. Chipperjeld P . G. Nelson and C . F . Stoneman trimeric struct~re.’~ There has also been a thorough study of all the lower chlorides of molybdenum; solid MoCl, MoCl, and MoCl have structures based on MoCl octahedra but there are signs (a particularly short Mo-Mo distance and a very low magnetic moment) of M-Mo interactions in MoCl,, and MoCl is a cluster (Mo6CI,)C14 (both WCl and WC1 are clusters; see ab~ve).’~ A certain amount of interest is being shown in the transition-metal chloro-fluorides.The complete range of compounds of formula WCl,F,- is now known this year’s additions being WCl,F WC14F2 and WC12F for which n.m.r. evidence was obtained.95 The compounds MoCl,F and ZrCl,F have been made by treating the corresponding chlorides with arsenic trifl~oride.~~ There has been negative and positive progress on the question of the exist-ence of neutral eight-co-ordinate complexes of the tetrapositive ions the claimed preparation of [MoCl,(Ph,AsO),] has been questioned ;” but preparations have been reported of complexes of the type [W(CN),(RNC),], and of [W(NC9H6 O),] (NC9H6 -OH = 8-hydroxyquinoline) which is be-lieved to be the first completely chelated eight-co-ordinate complex of tungsten.’* Successful preparations of some pentapositive complexes have been described using ligands that avoid the common problem of reduction of the metal to the tetrapositive state uiz.2,4,6-trimethylpyridine and (for W but not Mo) PhCN; the complexes appear to be of the type [MX,L,]X.” More differences between molybdenum and tungsten in the hexapositive state have been found X-ray studies show that MoOF (as well as TcOF, and ReOF,) contains octahedral units linked into chains (through fluorine rather than oxygen atoms) while WOF has the (NbF,) structure where they are linked into rings ;loo nitrogen trifluoride reacts with molybdenum trioxide to give mainly NO[MoO,F,] but with tungsten trioxide togive NO[WOF,]. lo’ X-Ray studies also show that K2Mo3OlO contains both octahedral and square-pyramidal units the first example of five-co-ordinate Mo”.lo2 1.r. and Raman spectra of solutions of the trioxides in aqueous acids suggest that cis-[M02F3(H20)] - ions predominate in Swhydrofluoric acid; ~is-[M0,Cl,]~ -ions in 12~-hydrochloric acid ; [Mo02C1,(H20),] in 6~-hydrochloric acid ; and isopolymolybdates in M-perchloric acid there being no evidence for the 93 R. A. Walton and B. J. Brisdon Spectrochim. Acta 1967 23 A 2489; B. J. Brisdon D. A. Edwards D. J. Machin K. S. Murray and R. A. Walton J . Chem. SOC. (A) 1967,1825; P. M. Boorman, N. N. Greenwood M. A. Hildon and H. J. Whitfield ibid. p. 2017. 94 H. Schlfer H.-G. von Schnering J. Tillack F. Kuhnen H. Wohrle and H. Baumann Z. anorg. Chem. 1967,353,281. 95 G. W. Fraser M. Mercer and R. D.Peacock J . Chem. SOC. (A) 1967 1091. 96 L. Kolditz and U. Calov Z . Chem. 1966,6,431; L. Kolditz and P. Dagenkoib ibid. p. 347. 97 G. B. Allison and J. C. Sheldon Znorg. Chem. 1967,6,1493. 98 H. Latka Z. anorg. Chem. 1967,353,243; R. D. Archer and W. D. Bonds jun. J. Amer. Chem. 99 T. M. Brown and B. Ruble Inorg. Chem. 1967,6 1335. SOC. 1967,89 2236. loo A. J. Edwards G. R. Jones and B. R. Steventon Chem. Comm. 1967,462. ‘ 0 2 0. Glemser J. Wegener and R. Mews Chem. Ber. 1967 100 2474. B. M. Gatehouse and P. Leverett. Chem. Comm. 1967. 37 The Transition Elements 293 presence of MOz2+ species.46 As part of a study of compounds of the type A2MS, the unstable free acid H,WS has been obtained as a deep red solid, and shown to be a strong acid; the related compound (NH,),MoSe has also been reported.lo3 A considerable amount of work has been done on the heteropolyanions of molybdenum and tungsten particularly on their reduction ;lo4 e.g., [P2M18062]6- can be reduced in stages (three for Mo six for W) to The Manganese Group.-Manganese.Most attention has been given to the tripositive state the smallish number of complexes has been raised by the preparation of nitrogenous complexes of the types [ MnCl,L] [ MnCl,L,], [MnF,(H,O)(biL)],and [MnCl,(triL)],including the ammine [MnCl,(NH,),], to add to the types(MnCl,(biL)] and [MnCl,(H,O)(biL)] already and by the preparation of the acetylacetonate complexes [MnCl acac] and rMnCl acac,]' O 5 and complexes with potentially sexidentate ligands like ethylenediaminetetra-acetate of formula KMn(sexiX"),xH,O ;Io7 magnetic studies of nitrogen complexes of the types [MnCl,(biL)] [MnX,(H,O)(biL)], and [MnCl,(triL)] suggest that the co-ordination number is six in each case, with chloride bridging in the first;Io6 and X-ray diffraction shows that [( Mn(quadriXii)py),0],2py (quadriX" = phthalocyanate) contains the linear Mn-0-Mn grouping (cf.iron).Io8 The small number of tetrapositive complexes has also been raised by the preparation of a deep red-brown com-pound formulated as [MnO phen2](C104),,$H20 with a magnetic moment much lower than the spin- only value.Io6 X-Ray structure analysis reveals that the anions in KMnO and K,Mn04 are tetrahedral within experimental error there being no sign of a static distortion of MnO,,- which is ,E in q; the M n - 0 distance is longer in MnO,,- as expected."' Technetium.Work continues on the relatively simple chemistry of this element with the main interest being its differences from rhenium. In a further study of the solution chemistry of heptapositive technetium and its reduction, better evidence for the existence of Tc"' in alkaline solution was obtained, including its precipitation as greyish pink BaTcO, which seems to indicate that it is less unstable with respect to disproportionation than Rev'.11o The red precipitate formed when KTcO is reduced with iodide in hydrochloric CP2M18062112-. l o 3 G. Gattow and A. Franke. 2. anorg. Chem. 1967 352 11. 246 A Miiller. B Krebs. and E. Diemann Angew. Chem. Internat. Edn. 1967,6 257. lo4 P. Souchay R. Contant and J.-M.Fruchart Compt. rend. 1967 264 C 976; P. Souchay and R. Contant ibid. 1967 265 C 723; G. Herve and P. Souchay ibid. p. 805; M. T. Pope and E. Papaconstantinoy Znorg. Chem. 1967,6 1147 1152. lo5 H. Funk and H. Kreis Z. anorg. Chem. 1967,349,45. lo6 H. A. Goodwin and R. N. Sylva Austral. J. Chem. 1967,20 629. lo' Y. Tsunoda and T. Takeuchi J. Chem SOC. Japan 1966 87 626; R. E. Hamm and M. A. lo* L. H. Vogt A. Zalkin and D. H. Templeton Znorg. Chem. 1967 6 1725. log G. J. Palenik Znorg. Chem. 1967,6 503 507. ' l o C. L. Rulfs R. A. Pacer and R. F. Hirsch J . Znorg. Nuclear Chem. 1967 29 681. Suwyn Znorg. Chem. 1967,6 139 294 A . B. Blake J . R. Chipperfield P. G. Nelson and C. F . Stoneman acid is K,[Tc(OH)CI,] not K,[Tc20Cllo] (Re forms both);"' the ammonium salt of the intermediate ion [TcOCI,]~- (cf.[ReOC1,I2-) has been made.", Rhenium. Recent advances in the co-ordination chemistry of rhenium have been reviewed. ' As with the heavier elements of the vanadium and chromium groups, considerable attention has been given to rhenium clusters particularly those of the type exemplified by [C14Re-ReC1,]2- which arrangement now seems to be as persistent as that of Re,Cl, it has been shown by X-ray structure analysis that [Re2cI6(Et3P),] is certainly of this type;" in a study of the reactions of Re,Cl,,- and Re,Brs2- with various oxygen and sulphur ligands, many more complexes thought to be of this ty@ (sometimes with two more ligands in the axial positions) were obtained e.g. [Re,Cl,(AcO) py2] with bridging acetates;' l 5 diamagnetic [Re2(NCS)812 - (as well as [Re(NCS)6] -1 has been prepared from Re2C1,,- and NCS- (the adduct of this with triphenyl-phosphine [Re,(NcS),(Ph,P),] seems not to have a Re-Re bond how-and it has been shown by polarography that Re,Cl,,- and Re2(NCS)82- are reduced reversibly in two one-electron steps according to the theoretical prediction that Re2XS3 - (cf.the known Tc2Cls3-) and Re2X8,-should exist with the Re2X,,- structure almost unchanged.'I7 On the other hand it has been shown by X-ray structure analysis that crystalline ReCI, (unlike TcCl,) contains Re2C19 units with the W,Clg3 - structure linked into chains.'14 This makes it difficult to speculate about the structures of the Re,X,- ions (X = C1 or Br) obtained by oxidising Re,X8,- with X, and the Re2Xg2- ions obtained by reducing either ReC1 in the presence of C1- or the Re,X - ions.l1 * Perhaps surprisingly X-ray crystallography reveals that [ ReNCl,(Ph,P),] and [ReNCl,(PEt,Ph),] are simply five- (square pyramidal) and six-co-ordinate respectively,11g and that ReF is body-centred cubic at room tempera-ture like IF ;120 ReF6 near its m.p. is also cubic like the other transition-metal hexafluorides,'20 which display the contraction expected for low-spin octa-hedral compounds in going from do to d6. The Iron Group.-Iron. The main specific interest in dipositive iron has ''I M. Elder J. E. Fergusson G. J. Gainsford J. H. Hickford and B. R. Penfold J . Chem. SOC. '" B. Jeiowska-Trzebiatowska S. Wajda and M. Baluka Zhur. strukt. Khim. 1967 8 519; l'' J.E. Fergusson Co-ordination Chem. Rev. 1966,1,459. '14 M. J. Bennett F. A. Cotton B. M. Foxman and P. F. Stokely J . Amer. Chem. SOC. 1967, (A) 1967,1423. B. Jezowska-Trzebiatowska and L. Natkaniec ibid. p. 524. 89,2759. F. A. Cotton C. Oldham and R. A. Walton Inorg. Chem. 1967 6 214. '16 F. A. Cotton W. R. Robinson R. A. Walton and R. Whyman Inorg. Chem. 1967 6 929; '17 F. A. Cotton W. R. Robinson and R. A. Walton Inorg. Chem. 1967,6 1257. '18 F. A. Cotton W. R. Robinson and R. A. Walton Inorg. Chem. 1967,6,223; F. Bonati and F. A. 'I9 P. W. R. Corfield R. 3. Doedens and J. A. Ibers Inorg. Chem. 1967.6. 197; R. J. Doedens and R. A. Bailey and S. L. Kozak ibid. p. 419. Cotton. ibid p. 1353. J. A. Ibers ibid. p. 204. S. Siege1 and D. A. Northrop Znorg.Chem. 1966,5,2187 The Transition EZements 295 been in the problem of the cross-over between the high- and low-spin states of its octahedral complexes. Magnetic measurements are here aided not only by n.m.r. i.r. and optical spectroscopy but also by Mossbauer spectroscopy. Evidence for the cross-over between the two states has been given for [Fe(BR,H),] (R = l-pyrazo1yl),l2' [Fe(biL),]X [biL = (2-pyridylmethy1)-amine; X = C1 Br or I],'22 [Fe(triL),]X [triL = 2-(2-pyridylamino)-4-(2-pyridyl)-1,3-thiazole],1z3 and [FeX phen,] (X = NCS or NCSe),lz4 as well as for several octahedral complexes of dipositive cobalt;''5 in the case of [Fe(BR,H),] the cross-over to low-spin is accompanied by a change of colour from white to magenta and is shifted in opposite directions by substi-tution of the hydrogen on the boron and by substitution of the hydrogens of the pyrazole ring.It has been shown that the black material obtained by re-crystallising yellow trans-[Fe(NCS) py4] from chloroform is not an isomer but the yellow form containing a small amount of some Fe"' derivative; it is not obtained when deoxygenated chloroform is used. 26 Work on tripositive iron has been more diverse. X-Ray crystallography reveals that FeC1,,6H20 is tr~ns-[FeC1,(H,0)~]C1,2H,0,'~~ and that the co-ordination in [Fe(NCS),(quinqueL)]ClO and [ {Fe(HzO)(quinqueL)),O]-(CIO,) (quinqueL is a nitrogen macrocycle) is pentagonal bipyramidal ;lZ8 mass spectroscopy shows that gaseous FeF like FeCl, but unlike CrF and MnF, contains dimers ; 29 spectrophotometry and conductiometry indicate that FeF,' FeF,- Fe(CN),+ Fe(CN), Fe(CN),- Fe(N,),-,and Fe(NCS)63-are prominent species in dimethyl sulphoxide,'30 a list very different from the corresponding one for water ; and magnetic measurements seem to indicate that the square-pyramidal complexes [FeX(S2CNR2)2] possess three unpaired electrons instead of the usual five or one for Fe1".I3l Attention has however, been focused on five co-ordination ( q .~ . ) and on complexes containing the Fe-0-Fe grouping X-ray crystallography has established that it is present in [ { Fe(H,O)(quinq~eL)),O](ClO~)~ already mentioned and in (enH,)[ { Fe(quinqueX"')) 20] where quinquex"' is (02C* CH2)ZN. [CHJ,*N(CH,*COJ* [CH,] *OH, and shown it to be approximately linear ; l z 8 ~ 13' and the low magnetic suscepti-12' J.P. Jesson and J. F. Weiher. J . Chem. Phys. 1967,46 1995; J. P. Jesson S. Trofimenko and lZ2 G. A. Renovitch and W. A. Baker jun. J . Amer. Chem. SOC. 1967,89,6377. 123 R. N. Sylva and H. A. Goodwin Austral. J . Chem. 1967 20,479. lZ4 I. Dtzsi B. Molnk T. Tarnkzi and K. Tompa J . Inorg. Nuclear Chem. 1967 29 2486; lZ5 J. G. Schmidt W. S. Brey jun. and R C. Stoufer Inorg. Chem. 1967,6 268; D. L. Williams, lZ6 C. D. Burbridge M. J. Cleare and D. M. L. Goodgame J . Chem SOC. (A) 1966 1698. 12' M. D. Lind J . Chem. Phys. 1967,47,990. E. Fleischer and S Hawkinson J . Amer. Chem. SOC. 1967,89,721. lZ9 K. F. Zmbov and J. L. Margrave J . Znorg. Nuclear Chem. 1967,29,673. B. Csiszar V. Gutmann and E. Wychera Monatsh. 1967,98 12. 13' R. L. Martin and A.H. White Inorg. Chem. 1967,6 712. 132 S J. Lippard. H Schugar. and C. Walling. Inorg. Chrm 1967 6. 1825. D. R. Eaton J . Amer. Chem. SOC. 1967,89 3158. E. Konig and K. Madeja Znorg. Chem. 1967,6,48. D. W. Smith and R. C. Stoufer ibid. p. 590. K 296 A. B. Blake J . R. Chipperfield P. G. Nelson and C. F. Stoneman bilities of salts and solutions of the [(Fe(quinqueXiii)) ,012- ion,'33 of the Schiff-base complexes [{ Fe(quadriX")),O] and of complexes of the type [{ Fe(biL)2)20]X2X;,nH20134 have been interpreted on the basis of its presence though those of partially hydrolysed Fe3 + solutions have been taken to indicate the presence of species containing the Fe(OH),Fe grouping.' 3 3 Ruthenium and osmium. Very little of note has been published on these elements that does not belong to the following report.X-Ray i.r. and magnetic studies have confirmed that a-RuC1 has the a-TiC1 structure and P-RuCl, the P-TiCl structure in both of which the co-ordination of the metal is octa-hedral; the a-form is antiferromagnetic below 1 3 " ~ and the P-form below about 6 0 0 " ~ (note that the strong-field configurations of Ti3 + and Ru3 + are related in It is reported that thermal decomposition of OsCl gives O S C ~ ~ . ~ with a fairly narrow stability range; it is black crystalline and iso-morphous with a-RuC1,; in the presence of oxygen materials formulated as OsOo. 5C13 and OsOC1 were also isolated. 13' The Cobalt Group.-Cobalt. Most of the work of specific significance has been concerned with the electronic structure and stereochemistry of dipositive cobalt a topic that has been reviewed.'" Particular attention has been given to five-co-ordination (+a).It has been found that the MF6 octahedron in the series of essentially isostructural compounds Ba,MF (M = Fe Co Ni Cu, or Zn) is compressed for all (particularly for copper) except cobalt where it is elongated while compression or elongation will remove the degeneracy of tg,e only elongation will remove that of t:,e,2.l3' It has been discovered that Co" is only tetrahedral in KCl-ZnCl melts but both tetrahedral and octa-hedral in ZnCl2-A1Cl3 melts (like Nim in the former melt) a provoking differ-ence;13' and that the dark blue or green complexes obtained from the organic free radical Bu',NO and COX (X = C1 Br or I) of formula CoX2(But2NO), may be tetrahedral with low magnetic moments (2.7-2-9 B.M.) due to spin-pairing between the odd electrons of the ligands and the d electrons of the cobalt.'40 The very small number of square-planar Con complexes has been increased by the addition of the complex [Co(MeCS* CH *CSMe),] reported last year and now characterised by X-ray crystallography (the diamagnetic nickel analogue has the same ~tructure),'~~ and'by the preparation and charac-terisation of the complexes [Co{H,N~CN*NH*C(NH)*OR},] (for R = Bu" the complex is isomorphous with the corresponding nickel compound)'42 and [M(1,2-S-C6HlO*NMePh),] (C6H12 = cyclohexane; M = Co Ni Pd and 133 H.Schugar C. Walling R. B. Jones and H. B. Gray J . Amer. Chem SOC. 1967,89 3712. 134 (a) J. Lewis F. E.Mabbs and A. Richards J . Chem SOC. (A) 1967 1014; (b) A. V. Khedekar, 135 J. M. Fletcher W. E. Gardner A. C. Fox and G. Topping J. Chem. SOC. (A) 1967 1038. 136 H. Schlfer and K.-H. Huneke J . Less-Common Metals 1967 12 146. 137 R. L. Carlin Transition Metal Chem. 1965 1 1. 13* H. G. von Schnering 2. anorg. Chem. 1967,353 13. 139 C. A. Angel1 and D. M. Gruen J . Znorg. Nuclear Chem. 1967,29,2243. 140 W. Beck K. Schmidtner and H. J. Keller Chem Ber. 1967 100 503. 14* R. Beckett and B. F. Hoskins Chem. Comm 1967,909. 142 V. Rasmussen and W. A. Baker jun. J . Chem SOC. (A) 1967 1712. J. Lewis F. E. Mabbs and H. Weigold ibid. p. 1561 The Transition Elements 297 Pt);', all these compounds have magnetic moments in the region of 2.5 B.M. at room temperature. The magnetic moments of the dimeric complexes [Co(H O)(quadriL)]t+ and [C~X'(quadriL)]',~- 2v)+ where quadriL is a nitrogen macrocycle have been taken to indicate Co-Co bonding'44 (cf.[(MeNC),Co-Co(CNMe),](C10,),). And the optical absorption spectra of cobalt in some garnets have been taken to indicate the presence of not only tetrahedral and octahedral but also dodecahedra1 Co2 + (and tetrahedral as well as octahedral Co3+).14, Less of significance has appeared on tripositive cobalt though it still figures prominently in the study of co-ordination chemistry. Most striking perhaps is the discovery that the new dark green compound [Co(CF CO CH CO CF,),] is reduced by water to red [CO(CF~*CO*CH*CO-CF,),(H,O),];'~~ its magnetic moment has' not yet been determined. Polynuclear cobalt (nr) ammines have been reviewed;'47 syntheses of a wide range of dinuclear ammines starting from Werner's [(NH,),CO(NH,,OH)CO(NH~)~]~+ and [(NH,),CO(NH,,O,)CO(NH,),~~ + have been given and evidence has been obtained for the presence of substantial proportions of dimers, perhaps [(H,O),CO(OH)~CO(H~O)~]~+ ions in aqueous Co"' solutions, even at high a~idities.'~' Finally as if to mark the centenary of Alfred Werner's birth two new classes of isomerism have been established, viz.'summation isomerism' (which was first suggested in 1956) by the preparation of cis-[CoBr(Cl- CH CH NH,)en,](NO,) and cis-[CoCl(Br. CH -CH - NH2)en2](N03)2,150 and 'fused chelate ring isomerism' discussed in the biological section. The new compound K[Co(HN*CO. NH CO NH),] is mentioned under the heading Nickel.Rhodium and iridium. As with ruthenium and osmium most of the progress has been in the areas covered by the following report. The preparation and separation of cis- and trans-[RhCl,(H,O),]- and of cis- and trans-[IrCl4(HZO),] and [IrC14(H20)2]- and fuc- and mer-[IrCl,(H,O),] + and [IrCl,(H,O),] have been claimed the IrIV complexes being strong oxidising agents. The Nickel Group.-A review of the chemistry of zeropositive nickel, palladium and platinum has appeared. 5 2 E. Wenschuh 2. Chem. 1966,6,226. D. L. Wood and J. P. Remeika J . Chem. Phys. 1967,46 3595. 144 J. L. Love and H. K. J. Powell Inorg. Nuclear Chem Letters 1967 3 113. 14' M. Kilner F. A. Hartman and A. Wojcicki Inorg. Chem. 1967 6 406; H. Veening W. E.Bachman. and D. M. Wilkinson. J . Gas Chromatog 1967. 5. 248 14' A. W. Chester ref. 8 p. 78. 14* A. G. Sykes and R. D. Mast J . Chem. SOC. (A) 1967 784. 149 M. Anbar and I. Pecht J . Amer. Chem SOC. 1967,8!9 2553. S. C. Chan Znorg. Nuclear Chem. Letters 1967 3 177. K. L. Bridges and J. C. Chang Znorg. Chem. 1967 6 619; A. A. El-Awady E. J. Bounsall, and C. S. Garner ibid. p. 79. 1.52 L. Malatesta R. Ugo and S. Canini ref. 8 p. 318 298 A. B. Blake J. R. Chipperfield P. G. Nelson and C. F. Stoneman Nickel. The main attention here has been on the stereochemistry of di-positive nickel especially five-co-ordination (4.u.) and transitions between tetrahedral square planar and octahedral. Thus on the one hand isomers with different stereochemistries continue to be isolated e.g.the tetrahedral blue and octahedral yellow forms of Ni(HN- [CH,] *CS)2C12,'53 and the square-planar orange and octahedral yellow- and blue-green forms of Ni(benzimidazole),BrZ,' 54 while on the other hand various physico-chemical studies of the transitions between stereochemistries continue to be made. X-Ray crystallography shows that bis(N-isopropyl-3-ethylsalicy1ideneiminato)-nickel@) is approximately tetrahedral whereas the analogous 3-methyl compound is square planar which emphasises how small is the energy difference between these two stereochemistries in such complexes.' 5 5 The magnetic susceptibilities of solutions of NN'-disubstituted aminotroponeimin-ate complexes in trichloromethane etc. (known to be in tetrahedral-square planar equilibrium therein) have been found to decrease with increasing pressure, indicating that the square-planar form has the smaller volume; but those of N-substituted salicylideneiminate complexes increase with increasing pressure, indicating that associated octahedral complexes are formed and ruling out any extensive occurrence of tetrahedral-square-planar or square-planar singlet-triplet eq~i1ibria.I~~ The complexes Ni(Ph,P* [CH,]; PPh,)X (X = C1 or Br) are diamagnetic for n = 2 and paramagnetic for n = 4 while for n = 3 there is reported to be an equilibrium between dia- and para-magnetic specie^.'^' The magnetic moments of the compounds [Ni(cis-Ph,P- CH CH PPh,),]X, (X = NO3 or C10 ) are intermediate between dia- and typical para-magnetfc values and as there is no evidence for co-ordination of the anions a square planar singlet-triplet equilibrium has been suggested.5 8 The influence of the axial ligands on the ground state of the complexes Ni(quadriL)X (quadriL is a nitrogen-sulphur macrocycle) has been studied magnetically and spectro-scopically for X = C104 and I the complexes are square planar while for X = NCS C1 and N they are octahedral (for X = Br the magnetic moment is 1.6 B.M. suggesting the presence of both environments).'59 It has been found that while the magnetic moments of pseudo-tetrahedral [NiBr2L2] and (Et,N)[NiBr,L] (L = benzimidazole) are still fairly high at ~ O K as expected that of (Ph,MeAs),[NiCI,] is only 0.7 B.M. in agreement with theory for a Tlg term and consistent with regular tetrahedral symmetry for the NiC1,2- ion in this salt even at this low ternperature.l6' It appears that the band responsible for the red colour of solid bis(dimethylg1yoximato)-nickel(@ is not directly associated with metal-metal interactions but is an S.K. Madan and M. Sulich J Inorg. Nuclear Chem 1967 29. 1765 D. M. I Goodgame M. Goodgame and M. J Weeks. J . Chem Soc (,4) 1967 1135. "' R. L. Braun and E. C. Lingafelter Acta Cryst. 1967 22 780. 15' A. H. Ewald and E. Sinn Znorg. Chem. 1967,6,40. '" S. S. Sandhu and M. Gupta Chem and Znd. 1967,1876. H. N. Ramaswamy H. B. Jonassen and A M. Aguiar Znorg. Chim Acta 1967 1 141. G. R. Brubaker and D. H. Busch Znorg. Chem. 1966,5,2114. D. M. L. Goodgame M. Goodgame and M. J. Weeks J . Chem. SOC. (A) 1967,1676 The Transition Elements 299 intramolecular charge-transfer transition shifted and intensified by inter-molecular effects,16' like that which gives Magnus's green salt [Pt(NH3)4] [PtCI,] its colour.162 The compounds MX(biX) (M = Ni or Pd; biX = diphenylglyoximate; X = Br or I) obtained by treating M(biX) with bromine or iodine have been shown not to be tripositive compounds they are diamagnetic and the halogen, which is readily dissociated appears to be present as X molecules stabilised by a charge-transfer interaction.163 However oxidation of the Ni" complexes of some cyclic tetramines does yield tripositive complexes e.g. [Ni(N03), (quadriL)] + they have the one unpaired electron required for low-spin d7. A tripositive complex KNi(bi) (H2bi = H,N*CO*NH .CO-NH2) is also obtained when K,Ni(bi) is oxidised with persulphate in alkaline solution ; it is blue-black with a magnetic moment of 2.5 B.M.like that of low-spin square-planar Co" complexes yellow KCo(bi) is isomorphous with it and brown almost diamagnetic KCu(bi),. may have a similar structure also ;I6' the promised 'further structural investigations' are awaited with interest. Palladium and platinum. As with the other platinum metals the next report contains most of the significant work on palladium and platinum. The thermochemical properties of aqueous Pd2 + and Pd(CN)42 - ions have been determined and compared with those of the corresponding nickel ions;'66 those of the M2+ ions are markedly different (the value of Sg9* differs by 49 cal. O K - ' mole-') as expected for Ni(H20),2' and Pd(H,0)42+.A new form of palladium dichloride has been prepared which is isomorphous with platinum dichloride and contains discrete Pd6Cll molecule^.'^^ X-Ray diffraction shows that in [PdC12(H4R)],5H20 the H4R (ethylenediaminetetra-acetic acid) is bidentate co-ordinated through the nitrogen atoms. N.m.r. spectroscopy shows that complexes like this are present in aqueous solutions of Pd" and H4R unless other co-ordinating anions (including OH-) are absent when the H4R is quadridentate.168 X-Ray crystallography shows that (NH,),PtS ,,2H2O contains the [Pt(S,)3]2 - ion with SS2 - chains forming six-membered chelate rings.169 The vibrations of palladium and p1atinu.m (and also gold) complexes especially those containing metal-halogen bonds have been intensively studied by far-i.r- and Raman spectroscopy (see particularly J.Chem. SOC. and Spectrochim. Acta) a striking result is that the stretching force-constants obtained for the 1 6 ' "' A. S. Foust and R. H. Soderburg J . Amer. Chem. SOC. 1967,89 5507. 164 N. F. Curtis and D. F. Cook Chem. Comm. 1967,962. J. J. Bour and J. J. Steggerda Chem. Comm. 1967,85. K. M. Izatt D. Eatough and J. J. Christensen J . Chem. SOC. (A) 1967 1301; R. M. Izatt, G. D. Watt D. Eatough and J. J. Christensen ibid. p. 1304. H. Schafer U. Wiese K. Rinke and K. Brendel Angew. Chem. Internat. Edn. 1967,6 253. Y. 0. Aochi and D. T. Sawyer Inorg. Chem. 1966 5 2085; D. J. Robinson and C. H. L. P. E. Jones and L. Katz Chem. Comm 1967 842. B. G. Anex and F. K. Krist J . Amer. Chem SOC. 1967,89 61 14.B. G. Anex M. E. Ross and M. W. Hedgcock J . Chem. Phys. 1967,46 1090. Kennard Chem. Comm. 1967,1236 300 A. B. Blake J. R. Chipperfield P. G. Nelson and C. F. Stoneman Pt-0 bonds in K[PtCI,(MeCO*CH*COMe)] and the Pt-C bonds in Na,[PtCl,(MeCO CH - COMe),] have very similar values.' 7 0 The Copper Group.-Copper. As with nickel the main focus has been on the stereochemistry of dipositive copper. Particular attention has been given to (a) dinuclear complexes (b) distorted tetrahedral uis-h-uis square-planar co-ordination and (c) five-co-ordination (4.u.). (a) X-ray crystallography shows that the complexes [Cu(o-AcO C & + * CO,),] and [Cu(6-aminopurinate),(H20)],3H,0 have dinuclear structures like [CU(ACO)~(H,O)] but the Cu-Cu distance in the second one is 2-95 A which is significantly longer than the 2-61-2-64 A of the other four complexes of this type; no magnetic measurements were made.17' X-Ray crystallography also shows that the ion [(H20)4Cu(H2 0) z CdH 2 0 ) 4 1 +, with an asymmetric bridge may be present in the compound Cu3Zr2F14, 16H20.J8 A magnetic and i.r.spectral study of the complexes [CuX,L] and [CuX,L,] (X = Cl or Br ; L = substituted quinoline N-oxides) revealed two types of [CuXzL] complex oxygen- and halogen-bridged depending on the substituents in L.17 The presence of a certain strongly polarised absorption band in the visible region is said to be diagnostic of dinuclear complexes.173 (b) In a study of the complexes [CuCI,L] and [CuCl,L,] (L = pyridine N-oxide 3- and 4-picoline N-oxide and 2,6-lutidine N-oxide; cf.L = quinoline N-oxide) in which it was shown that the former are dinuclear like their prototype [CuCl2(CSHSNO)] it was found that the latter are dimorphic the green forms are believed to be trans-square-planar and the yellow forms tetrahedral.' 74 The complexes [CuBr,(Me,N*R* NMe2);d are thought to be square planar for R = [CH,] and CH2* CHMe (dark green) and tetrahedral for R = [CH,], (orange). ' The cubic compound KZPb[Cu(NOz),] continues to excite interest a neutron diffraction study provided no evidence for disorder and it seems that the space-average configuration is regular octahedral ;176 thus a dynamic effect has to be invoked to account for its electronic spectrum and to satisfy the Jahn-Teller theorem. The new six-co-ordinate cation [Cu{(Me,N),PO- 0- OP(NMe,) I3l2 + is of interest in being colourless which puts the ligand very low down in the spectrochemical series.' 7 7 A brown tripositive complex K[Cu(bi),] is obtained 170 G.T. Behnke and K. Nakamoto Inorg. Chem. 1967,6 433 440. 171 L. ManojloviC-Muir Chem. Comm. 1967 1057; E. Sletten ibid. p. 1119. 17* R. Whyman D. B. Copley and W. E. Hatfield J . Amer. Chem. SOC. 1967,89 3135. 173 R. D. Willett J . Inorg. Nuclear Chem. 1967 29 2482; R. D. Willett and 0. L. Liles Inorg. 174 M. R. Kidd R. S. Sager and W. H. Watson Inorg. Chem. 1967,6 946. 17) I. Bertini and F. Mani Inorg. Chem. 1967,6 2032. ''~5 N. W. Isaacs C. H. L. Kennard and D. A. Wheeler Chem Comm. 1967 587. 177 M. D. Joesten and J. D. Forbes J . Amer. Chem. SOC. 1966,88 5465.Chem. 1967,6 1666 The Transition Elements 301 when K,Cu(bi) is oxidised with persulphate in alkaline solution ; its magnetic moment (0.4 B.M.) seems to suggest square-planar geometry (cf. Nickel). 165 Silver and gold. There is little to report here on these two elements. A group of isomorphous compounds AAg,I with exceptionally high ionic conductivi-ties (that of RbAg,15 being higher than that of any other known solid) has been identified; X-ray crystallography suggests that the Ag+ ions are virtually in a liquid state inside a crystalline lattice formed by the A+ and I- ions the copper analogue KCu,15 is obtainable in the region of 300°.178 The four-co-ordinate complex cation [Ag((Me2N)2PO~O*OP(NMe,),},]+ has been made.177 The crystal structure of gold trifluoride has been determined; the gold atom is in a tetragonally-elongated octahedral environment of fluorine atoms as befits low-spin d8 (pure AuF is diamagnetic) with this included (but not as yet the d" compounds InF and TlF3) the molecular volumes of the low-spin trifluorides of the second and third series vary as expected i.e.decrease to d6 and then increase. 17' The dark orange complex [AuC13(2,2'-biquinolyl)] has been made and found to have a five-co-ordinate structure intermediate between trigonal bipyramidal and square pyramidal in geometry; this is the first example of five-co-ordinate Aunl to be established by X-ray crystallography : the bromide is isomorphous and the corresponding 2-(2-pyridyl)quinoline complexes are similar.'80 The Zinc Group.-Zinc.The ion Zn,2+ corresponding to Cd22 + and Hg22+, has been identified in the yellow glass produced by rapid freezing of a saturated melt of zinc in zinc dichloride; it dissolves in water to give a colourless solution which quickly deposits grey zinc particles and in saturated aqueous zinc chloride to give a greenish yellow solution which is stable for several days in the absence of moisture."' Apart from the fiveco-ordinate complexes dis-cussed later (4.v.) there is nothing else to report except perhaps the rather un-expected structures of the polymers Zn(R2P02) which contain alternate single and triple -0- PR2 0- bridges between tetrahedral zinc atoms.'82 Cadmium and mercury. Most of the work of specific significance has been concerned with five-co-ordination of dipositive mercury (43.) and the stereo-chemistry of dipositive mercury in general.X-Ray studies' of single crystals of red orange and yellow HgI have confirmed that the co-ordination of the mercury is tetrahedral in the red form and compressed octahedral (suggesting a description in terms of linear HgI molecules) in the yellow form.'83 The ligand 1,4-thioxan has been found to co-ordinate through its sulphur atom in tetrahedral [HgCl (S(CH CH,),O) ,] ;' 84 i.r. spectroscopy indicates that this may also be true of aryl sulphinates in the compounds [Hg(RSO,),] J. N. Bradley and P. D. Greene Trans. Faraday Soc. 1967,63,424,2516. R. J. Charlton C. M. Harris H. Patil and N. C. Stephenson Znorg. Nuclear Chem. Letters, D. H. Kerridge and S. A. Tariq J. Chem SOC.(A) 1967 1122. F. Giordano L. Randaccio and A. Ripamonti Chem. Comm. 1967 19 1239. 179 F. W. B. Einstein P. R. Rao J. Trotter and N. Bartlett J. Chem Soc. (A) 1967 478. 1966 2 409. 183 G. A. Jeffrey and M . Vlasse Znorg. Chem. 1967,6 396. 184 R. S. McEwen and G. A. Sim. J . Chern. SOC. (A). 1967 271 302 (which have been found to decompose thermally into HgR2 and This preference for sulphur is perhaps not too surprising. More surprising is the linear co-ordination by sulphur found in [Hg(PhN:C(OMe)S),] ; com-plexes like this are usually tetrahedral with &her atoms in the ligand co-ordinated linear co-ordination is known in cinnabar. 18' The six-co-ordinate cation an uncommon type formercury [Hg{(Me,N),PO* 0*OP(NMe2)2>3]2 + has been prepared. ' The compound Hg4S2(C104) is produced when aqueous Hg,(ClO,) is treated with HgS ; it is white and insoluble and has evidently to be formulated as a mixed mercury(I)-(II) c~mpound.'~' The first compounds to contain a Hg-B bond have been obtained including orange A2[Hg(BloHl,),] which is like its zinc and cadmium counterparts.'88 Ligds.-In this section we report work in which the ligand is of primary interest.A general review of ligands in which at least one of the co-ordinating atoms is nitrogen has appeared.18' The subject of linkage isomerism has been re-viewed,'g0 and linkage isomers of the cyanide' g' and ~elenocyanate"~ groups have been reported. A number of four- and five-co-ordinate complexes of thiocyanate and selenocyanate with various transition metals have been prepared as salts with large cations and the mode of linkage (determined from i.r.spectra) is found to be in accordance with the 'hard' (N-bonded) or 'soft' (S- or Se-bonded) character of the metal ion.'93 A study of the equilibria between bis(dimethy1glyoximato)-cobalt(I1) and -iron(Ir) and halide and pseudo-halide ions showed that low-spin complexes are formed and it is of interest that SCN- and SeCN- are apparently co-ordinated through the S and Se atoms.'94 The chemistry of inorganic azides has been reviewed,lg5 and the prepara-tion and electronic spectra of the complexes [MN(N,),](6-N)- (MN = Cr"', RuI'I Rhl'' Ir"' or Pt'") and [MN(N3)4](4-N)- [MN = Mn" Zn" Pd" Pt", Au"' (VO)" or (UO,)'] have been reported.Ig6 The spectra of the complex ions [M(N02),J2- (M = Mn Co Cu Zn Cd or Hg) indicate bonding through oxygen with the nitrite probably bidentate in the manganese cobalt cadmium, and mercury cornple~es.'~~ It is reported that the reaction of trans-A.B. Blake J . R. Chipperfield P . G. Nelson and C. F. Stoneman ''' G. B. Deacon Austral. J . Chem. 1967,20 1367. lS6 R. S. McEwen and G. A. Sim J . Chem SOC. (A) 1967 1552. J. W. BouKnight. R. Layton. and J. E Lewis. Innrq. Nuclear Chem Letters. 1967. 3. 103 N. N. Greenwood and N. F. Travers Chem. Comm. 1967,216. W. P . Griffth Developments Inorg. Nitrogen Chem. 1966,1,241 see also ref 8. 190 R. T. M. Fraser ref. 8 p. 295. 19' K. Kuroda and P. S. Gentile Inorg. Nuclear Chem. Letters 1967,3 151. 192 J. L. Burmeister and H. J. Gysling Chem. Comm. 1967 543.lg3 H.-H. Schmidtke and D. Garthoff Helv. Chim. Act4 1967 50 1631. ' 94 K. Burger and B. Pinttr J . Inorg. Nuclear Chem. 1967,29 171 7 . lgJ A. D. Yoffe Developmenfs Inorg. Nitrogen Chem. 1966,1 72. 19' H.-H. Schmidtke and D. Garthoff J . Amer. Chem. SOC. 1967,89 1317; W. Beck E. Schuierer, P. Pbllmann and W. P. Fehlhammer Z. Naturjbrsch. 1966 21b 81 1 ; W. Beck W. P. Fehlhammer, P. Pollmann E. Schuierer and K. Feldl Chem. Ber. 1967 100 2335 The Dunsition Elements 303 [Pt(N02)2(NH3)2] with hydrochloric acid gives a complex, [Pt CldNOz )(NH 3)(NHzcl)], containing co-ordinated monochloroamine. 19* Further examples of co-ordinated perchlorate have been found. The i.r. spectrum of the monoclinic form of trans-Co diarsz(C1O,) suggests strong metal-perchlorate interaction whereas in the orthorhombic forms the anions are only weakly associated with metal ; in the isomorphous mono-metal-perchlorate interaction whereas in the ortho-rhombic form the anions are only weakly associated with the metal; in the isomorphous mono-clinic nickel complex the co-ordination of the perchlorate is somewhat weaker, as expected for the d8 c~nfiguration.'~~ Dehydration of octahedral Ni phen,(C1O4),,3H,O and Ni bipy,(C10,)2,2$H,0 gives anhydrous com-pounds with colours and magnetic moments similar to those of the hydrates.'" The crystal structure and i.r.spectrum of Cuen,(BF,) indicate weak co-ordination of the tetrafluoroborate ions,201 while the effect of PF6- on the rate of the reaction between Fe2+ ions and hydrogen peroxide has been interpreted as indicating formation of a relatively stable species Fe(PF6)+.202 The chemistry of nitrate complexes has been reviewed.'03 The compound TiCl,(MeNO,), in which nitromethane seems to be acting as a bidentate ligand has been reported.'04 An extensive review of the chemistry of P-keto-enolate complexes has been published,205 and briefer reviews of their stereochemistry,206 and of the detailed molecular structures of acetylacetonate and salicylideneiminate chelatesZo7 have appeared.The i.r. spectra of the tris(acetylacetonato)metal(IIr) complexes of the first series have been correlated with the ligand-field splittings increase in A is accompanied by strengthening of the C-C bonds at the expense of the C-0 bonds.208 The compounds [Cr(RCO-N*COR),] (R = Me or Ph) have been prepared and their i.r.and electronic spectra found to be very similar to those of the corresponding keto-enolate complexes.209 The complex [CO((E~O),PO*CH*CO~CH,)~] appears to exist as a deep-blue monomer and red trimer in solution; the solid trimer has been found to consist of two 197 D. M. L. Goodgame and M. A. Hitchman J . Chem. SOC. (A) 1967,612. 19* I. I. Chernyaev G. S. Muraveiskaya and L. S. Korablina Russ. J . Znorg. Chem. 1966,11 728. 199 F. W. B. Einstein and G. A. Rodley J . Znorg. Nuclear Chem. 1967,29 347; G. A. Rodley and 'O0 C. M. Harris and E. D. McKenzie J . Znorg. Nuclear Chem. 1967,29 1047. '01 D. S. Brown J. D. Lee B. G. A. Melsom B. J. Hathaway I. M. Procter and A. A. G. Tomlinson, 'O' C. F. Wells hnd M. A. Salam Trans.Faraday SOC. 1967,63,620. 203 C. C. Addison Co-ordination Chem. Rev. 1966 1 58; C. C. Addison and D. Sutton Progr. '04 A. H. Norbury and A. I. P. Sinha J . Chem SOC. (A) 1966 1814. '05 J. P. Fackler jun. Progr. Znorg. Chem. 1966,7,361. ' 0 6 J. P. Fackler jun. ref. 8 p. 580. '07 E. C. Lingafelter Co-ordination Chem Rev. 1966 1 151. ' 0 8 R. D. Hancock H. W. Sacks R. Thornton and D. A. Thornton Znorg. Nuclear Chem. Letters, ' 0 9 C. S. Kraihanzel and D. N. Stehly Znorg. Chem. 1967,6,277. P. W. Smith J . Chem. SOC. (A) 1967 1580. Chem. Comm. 1967,369. Znorg. Chem. 1967,8 195. 1967 3 51 304 A. B. Blake J . R. Chipperfield P. G. Nelson and C. F . Stoneman Co(biX) groups linked by a six-co-ordinate central cobalt atom ; the trimerisa-tion of the monomer thus involves an extensive rearrangement.,l' The chemistry of Schiff-base and P-keto-amine complexes has been re-viewed, ' ' and recent work on complexes of substituted salicylideneiminates has been summarised.2 N-phenylsalicylideneimine (RH) has been shown to form a cobalt@) complex [Co(RH),]Cl in which the ligand is apparently in the keto-form as well as [CoR,] derived from the enol form and these can be interconverted.The hexamine produced by condensation of MeC - (CH - NH,)3 with three molecules of pyridine-2-carboxaldehyde has been shown to have a cage structure with three tertiary amino-groups rather than the Schiff-base structure hitherto assumed ; however n.m.r. evidence shows that the reaction with Fe2+ ions gives a complex Fe(sexiL) + containing the ligand in the Schiff-base form the considerable energy of this isomerisation evidently being counteracted by the simultaneous formation of a sexidentate chelate of a low-spin d6 ion.214 Interest has been maintained in the multidentate ligands produced by reaction of ketones with co-ordinated primary amines.When [Feen,](ClO,), reacts with acetone the macrocyclic ligand 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyclotetradeca4,ll-diene is liberated l5 cobalt(Ir1) complexes of this have been prepared including two very closely related geometrical isomers of tran~-[CoCl,(quadriL)]ClO~.~ l6 Cobalt(n1) complexes of the corresponding tetradecane tetb have also been prepared," ' of the type [C~(biX')(tetb)](~ -')+, as well as the interesting cobalt(1r) complexes [C~X'(tetb)],(~-~")+ which seem to contain Co-Co bonds (see section Cobalt).144 Non-cyclic quadrident-ate ligands are formed when P-hydroxyketones react with salts of the [Ni enJ2 + ion and a range of six-membered chelate rings can be produced with a-hydroxyketones condensation occurs initially with the keto-group only to to give a six-co-ordinate complex of the type [Ni(H,N-CH CH *N CR CR'R" OH),]' + , which on refluxing is converted into square-planar [Ni(H,N- CH2 - CH N CR *CR'R''* NH CHI CH *NH,)]' + ; the latter can be reduced by NaBH to give a substituted triethylenetetramine Reaction of acetone with salts of the Ni(NH,),2* ion gives2"' yellow diamagnetic [Ni(HN CMe CH CMe NH,),] +. 'lo J. J. Bishop F. A. Cotton R. Eiss and R. P. Hugel Nature 1967 214 1 1 1 1 .''I R. H. Holm G. W. Everett jun. and A. Chakravorty Progr. Inorg. Chem. 1966 7 83; S. Yamada Co-ordination Chem. Rev. 1966 1 415. 212 L. Sacconi Co-ordination Chem Rev. 1966 1 126 192. '13 P. Bamfield J . Chem. SOC. (A) 1967 804. 214 D. A. Durham F. A. Hart and D. Shaw J . Inorg. Nuclear Chem. 1967,29 509. 21s N. Sadasivan and J. F. Endicott J . Amer. Chem. SOC. 1966,88 5468. 216 N. Sadasivan J. A. Kernohan and J. F. Endicott Inorg. Chem. 1967. 6,770. 217 P. 0. Whimp and N. F. Curtis J . Chem SOC. (A) 1966 1827. 218 (a) T. E. MacDermott and D. H. Busch J . Amer. Chem SOC. 1967,89 5780; T. E. MacDermott, B. E. Sewell and D. H. Busch ibid. p. 5784; (b) W. Jehn 2. anorg. Chem. 1967,351,260; N. J. Rose, M. S. Elder and D. H. Busch Inorg. Chem. 1967,6,1924 The Transition Elements 305 1 The new bi- and tri-dentate ligand anions dihydrobis-( 1 -pyrazolyl)borate, shown in (l) and hydrotris-(l-pyrazoly1)borate and some of their methyl substituted derivatives have been prepared and their complexes with dipositive ions of the first series investigated ; the tetrakis-jl-pyrazoly1)borate anion was also prepared but found to be tridentate ; the bidentate ligands give planar and tetrahedral complexes while the tridentate ligands give octahedral complexes, which are high-spin except in the d6 case (see section on Iron).219 A new multi-dentate ligand NN'-di-(2-hydroxybenzyl)ethylenediaminediacetic acid has been synthesised the 1 1 iron(Ir1) chelate of which has a stability constant nearly a million times greater than that of the most stable iron(rr1) chelate previously known.,,' A spectroscopic study has been made of the ligand-field strengths towards cobalt(rr1) of quadri- and sexi-dentate ligands with the following sets of co-ordinating atoms N,O, N2S2 N, As202 As2S2 N204 N2S202 or N402.The spectrochemical effects of ether-oxygen and sulphide-sulphur were found to be quite similar.221 X-Ray crystallography has established that the sulphite ion in trans-[Co(NCS)(SO3)en2],2H2O is co-ordinated through its sulphur atom.222 The interaction of square-planar complexes of the type [Ni(S2CR),]"-and nitrogenous bases has been investigated and it was found that high-spin adducts are formed when R is -CR; -OR and -NH2 (n = 0) but not when R is -NR; (n = 0) =S =NR' or = C R i (n = 2); it was suggested that in the latter cases there is sufficient transfer of x electrons to the nickel to inhibit acceptance of electrons from axial l i g a n d ~ .~ ~ ~ The addition of sulphur to dinegative complexes of the above type i.e. to [Ni(S2CR),I2- ions was found to give [Ni(S3CR)2]2- ions (including [Ni(CS4)2]2- which may also be prepared from KCS,); it was concluded that the sulphur atom is inserted into the four-membered chelate ring.224 Nickel@) and cobalt(I1) salts have been found to react with the carboranethiol (HS),C2BIo (H2R) to give square-planar complexes of the types [MRL,] [MR(biL)] and [MR],2- ; however, their spectra indicate that extensive x delocalisation of the type found in maleonitriledithiolate complexes does not occur in this system.225 Research on the donor properties of the cationic ligands N(CH2 -CH2),NR+ has been summarised ;226 the complexes formed include the types [MX,A], 214 J.P. Jesson S. Trofimenko and D. R. Eaton J . Amer. Chem. Soc. 1967 89 3148 3158. 220 F. L'Eplattenier I. Murase and A. E. Martell J . Amer. Chem. SOC. 1967,89 837. 221 R. D. Cannon B. Chiswell and L. M. Venanzi J . Chem SOC. (A) 1967 1277. 222 S. Baggio and L. N. Becka Chem Comm. 1967 506. 223 D. Coucouvanis and J. P. Fackler jun. Znorg. Chem. 1967,6,2047. 224 D. Coucouvanis and J. P. Fackler jun. J . Amer. Chem SOC. 1967,89 1346. '" H. D. Smith jun. M. A. Robinson and S. Papetti Inorg. Chem. 1967,6 1014. "' A. K . Banqiee. I- M. Vallarino. and J. V. Quapliano. Co-ordinofion Chm. Rev. 1966 1 239 306 A . B. Blake J . R. Chipperjeld P .G. Nelson and C. F . Stoneman [MX,(H,O)A] and [MA,I6+. A series of complexes of diphenylcycloprope-none has been prepared and their structures elucidated by spectroscopic and magnetic methods co-ordination is through the carbonyl oxygen in all cases, contrary to earlier suggestions that this ligand might co-ordinate through the double bond.,,' The organic free radical But2N0 reacts with anhydrous cobalt dihalides to give the curious complexes [CoX,(Bu',NO),] described under Cobalt;14' with palladium dichloride or dibromide it gives the equally curious diamagnetic halogen-bridged complexes [PdX(But2N0),] :228 it is clearly a 'suspect' ligand. 2 3 4 5 I I O H 0 6 Reactions of co-ordinated ligands have been reviewed229* 230 The reaction of [Pd(N3),(Ph3P),] with carbon monoxide at room temperature and pressure has been found to give [Pd(NCO),(Ph,P),] q~antitatively.~~' The complex [Ni(HN,S,),] reacts with formaldehyde formaldehyde and a primary amine, acetaldehyde and ammonia and glyoxal giving green compounds for which the structures (2) (R = 0 or NR') (3) and (4) have been proposed.232 Co-ordinated xanthates and dithiocarbamates have been shown to undergo nucleophilic substitution with piperidine i.e.[M(S,C-R),] + HNC5Hlo + [M(S2C*NC5Hl0),] + RH 227 C. W. Bird and E. M. Briggs J . Chem. SOC. (A) 1967 1004. "' W. Beck and K. Schmidtner. Chem. Ber. 1967 100 3363. 229 G. W. Watt and D. G. Upchurch ref. 8 p. 253. 230 J. P. Collman Transition Metal Chem. 1966 2 1. 231 W. Beck and W. P. Fehlhammer Angew.Chem. Znternat. Edn. 1967 6 169. 232 U. Thewalt and J. Weiss Z . anorg. Chem. 1966,348 238; ibid. 1967,352 225 The Transition Elements 307 where R = OR or NR2 and M = Ni Pd or Pt.233 The square-planar nickel@) complex (5) is oxidised in alkaline solution by oxygen or potassium iodate to the rather stable compound (6); the presence of a six-membered ring seems to be essential for this reaction suggesting that x delocalisation may provide the driving Suspect ligands. This section deals with complexes in which the oxidation state of the metal is not clearly defined. The year has again seen considerable activity in this area. The crystal structure of the complex (Bu",N)[Fe{ S,C,(CN) ),I has been found to contain dimeric anions (like [Co( S2C2(CF3)2) 2]2) with square-pyramidal co-ordination of the iron; this structure accounts for its magnetic properties.235 X-Ray crystallography reveals that the co-ordination in the anion [V(S,C,(CN) l3I2- is closer to octahedral than to the trigonal-prismatic arrangement of [V{ S2C2(CN),} 3] and that the corresponding titanium and chromium anions probably have the same structure; this suggests that the electronic distribution in these more highly reduced species approaches that of conventional MIv complexes and this picture is supported by the mag-netic moments of the ions [M(S2C2R2)3]n- (n = 2 M = Ti V Cr Mn or Fe; n = 3 M = Cr or Co) all of which are close to the values expected for octa-hedral low-spin M(6-n)+.236 Some complexes of the new ligand Se,C,(CF,) have been prepared e.g.[Ni{Se2C,(CF,)2),]" (n = 0 - 1 or -2); they resemble their sulphur ana-logues but are somewhat less stable.237 Electron-transfer reactions of square-planar nickel copper zinc and cadmium complexes of ligands with two sulphur and two nitrogen co-ordinating atoms have been further investigated the com-plex [Ni{ o-C6H4(NH)S >2] undergoes a oneelectron oxidation and two one-electron reductions; the zinc and cadmium anions [M(o-C,H,(NH)S),] -have anisotropic g-values close to the free-electron value and so contain free-radical ligands whereas the higher anisotropic g-value of the corresponding nickel anion indicates an appreciable nickel d orbital contribution to the odd-electron wavef~nction.~~~ The nickel and palladium complexes [M(quad-riX")] [H,quadriX" = butan-2,3-dione bis(2'-pyridylhydrazone)] have been shown to be the central members of five-membered electron-transfer series; such long series are known for other M-N4 systems but not for M-S4, M-N2S2 M-S202 or M-O4 systems.239 The red complex [Co(quadriX")] where quadriX" = NW-ethylenebis(salicylideneiminate) has been reduced to 233 J.P. Fackler D. Coucouvanis W. C. Seidel R. C. Masek and W Holloway. C'ltrrn Cor~ini, 234 E. G. Vassian and R. K. Murmann Inorg. Chem. 1967,6,2043. '" W. C. Hamilton and I. Bernal Znorg. Chem. 1967,6 2003. 236 E. I. Stiefel Z. Dori and H. B. Gray J. Amer. Chem. SOC. 1967 89 3353. 23' A. Davison and E. T. Shawl Chem Comm. 1967,670. 238 R. H. Holm A. L. Batch A. Davison A. H. Maki and T. E. Berry J. Amer. Chem. SOC. 1967, z39 0.A. Gansow R. J. Olcott and R. H. Holm J . Amer. Chern. SOC. 1967,89 5470. 1967,924. 89,2866 308 A. B. Blake J . R. Chipperfield P . G. Nelson and C. F . Stoneman a green mononegative anion thus forming the first M-N202 electron-transfer system. 240 A large number of electron-rich compounds have been prepared by the reduction of complexes of ligands such as 2,2'-bipyridyl 1,lO-phenanthroline, terpyridyl and phthalocyanine (pc) in non-aqueous solvents e.g. [M bipy,] 9 -(M = Si ,Ti or Zr) [Crterpy,]'~ '*'+ [Crbipy,]',2.3-6- [ F e p ~ ] ' * ~ ~ ~ ~ [Cebipy,]' and [Ubipy4]o*'-:24' in most of these the electrons are pre-sumably added to ligand antibonding orbitals stabilised by delocalisation through the central atom. Peroxides. Only complexes of 022 - and O2 - as opposed to complexes of 0,, are dealt with here this distinction is as suspect as the dioxygen moiety.The nature of the dinuclear peroxides of cobalt has been considerably clarified. X-Ray crystallography has shown that Werner's green paramagnetic [en2Co(NH2,O2)Coen2](NO,),,H2O contains an -0-0- bridge and that its red diamagnetic sister is [en2Co(NH,,02H)Coen2](N03),,2H20 with an -O(OH)- bridge;242 the brown diamagnetic salt obtained by treating these with ammonia has been shown to contain the one-electron reduc-tion product of the green ion i.e. [en,C0(NH,,0~)Coen,]~+ rather than [en,Co(NH,O,)Co en2] + as supposed by Werner ;243 and the large ' 7O hyperfine splitting in green [(NH,),CO(NH~,O~)CO(NH~),](NO~)~ has been offered as direct evidence that the unpaired electron is shared by the cobalt atoms via the -0-0- bridge:244 thus the green red and brown salts contain the superoxoCo(NH2,02)Co4+ hydroperoxoCo(NH,,02H)Co4+, and peroxoCo(NH2,02)Co3+ cobalt(rrr) moieties respectively.Cor-responding formulations have been proposed for salts of the green [(NH ,) Co( 02)Co(NH ,) 5] + red [(NH 3)5 (240 H)Co(NH ,),I + and brown [(NH3)5Co(02)Co(NH3)5]4+ single-bridged ions.245 Spectroscopic evidence has been given for the peroxide in peroxochloro-and peroxo-oxalato-anions of the metals of the titanium vanadium and chromium groups being bidentate as in the peroxofluoro-anions of these metals which means co-ordination numbers greater than six for these species.246 An interesting use of peroxides is in a method proposed for the extraction of niobium and tantalum that avoids hydrofluoric acid in which peroxo-complexes are extracted from sulphuric acid with esters of phosphoric acid.247 240 F.Calderazzo and C. Floriani Chem. Comm. 1967 139. 241 S. Herzog and H. Ziihlke Z . Chem. 1966,6 382 434; S. Herzog and U. Grimm ibid. p. 380; S . Herzog and H. Aul ibid. pp. 343 382; S. Herzog and E. Wulf ibid. p. 434; S . Herzog and R. Schuster ibid. 1967 7 26; S. Herzog and W. Waicenbauer ibid. p. 317; S. Herzog U. Grimm, and W. Waicenbauer ibid. p. 355; R. Taube and H. Arfert 2. Naturforsch 1967,22b 219; R. Taube and H. Drevs Angew. Chem. Internat. Edn. 1967 6 358; C. Mahon and W. L. Reynolds Inorg. Chem. 1967,6 1927. 242 U. Thewalt and R. Marsh J . Amer. Chem. SOC 1967.89. 6364. 243 M. Mori and J.A. Weil J . Amer. Chem. SOC. 1967,89 3732. 244 J. A. Weil and J. K. Kinnaird J . Phys. Chem. 1967 71 3341. 245 D. P. Mellor and N. C. Stephenson Znorg. Nuclear Chem. Letters 1967 3 431. 246 E. Wendling and R. Rohmer h l l . SOC. chim France 1967 8 ; E. Wendling ibid. p. 16; E. Wendling and J. de Lavillandre ibid. p. 2142; W. P. Griffith and T. D. Wickins J . Chem. SOC. (A) 1967 590 The Transition Elements 309 Cyanides. Transition-metal cyanides in and those containing bifunctional cyanide groups in particular,249 have been reviewed. The scope of cyanide ion as a ligand has been further extended by the possible discovery of the first mononuclear isocyanide complexes and first linkage isomers [Co(CN),(quadriL)]+ and [Co(NC),(quadriL)] +,I9’ and of the first proton-ated isocyanide complexes viz.Ag(NCH)+ and Ag(NCH) + in liquid hydrogen fl~oride,~” corresponding to e.g. Fe ~hen,(cNH),~ + in water. Of the new compounds perhaps the most interesting are the first yttrium and lanthanide cyanides M(CN),,2THF made in tetrahydrofuran (THF),” and K,V(CN)S and K,Cr(CN) made by heating known nitrosyl cyanides with hydrogen ; pink K,V(CN) is diamagnetic and recrystallisable from water, and it is suggested that it might contain the V2(CN),,”- ion.252 A great deal of structural work remains to be done on these and other cyanides;248 this year evidence has been put forward in favour of the six-co-ordinated formulations K,[M02(CN)4],6H20 and K3[MO(OH)(CN),],nH20 (M = Mo or W) rather than the eight-co-ordinate ones favoured previously,253 and for the formulation [Co(CN),H20I3 - with square-pyramidal Co(CN) for the main species present in the green solutions formed from aqueous Co2+ and CN- ;254 while the structures of H,Co(CN) and Ag,Co(CN) have been found by X-ray powder photography to be similar presumably with an N-H-N arrange-ment in the former related to the linear symmetrical N-Ag-N in the latter.255 The chemistry of Co(CN), -(R) which behaves as a free radical continues to attract attention ; it reacts with OC(CH CH),CO to give RO C6H4* OR6-, EtSH to give RSEt3- and CS2 to give RSC(S)R6-,256 and also with compounds that give R-C bonds.Classifications of moieties. This subject has been re~iewed.”~ The classification into hard and soft (a and b) has been widely employed. But two complications have emerged this year it has been found that the [Pd((H,N-CH -CH2),NH:I2+ ion is softer than the [Pd((Et2N*CH2* CH2)2NH )I2’ ion in terms of free-enthalpy (G) but harder in terms of e n t h a l ~ y ; ~ ’ ~ and that the inner-sphere behaviour of [CO(NH,),H,O]~+ is soft but the outer-sphere behaviour is hard2” (indeed 247 A.K. Babko and V. F. Gorlach Russ. J . Inorg. Chem. 1966,11 1526. 248 B. M. Chadwick and A. G. Sharpe Adv. Znorg. Chem Radiochem 1966,8 83. 249 D. F. Shriver Structure and Bonding 1966 1 32. 2 5 0 M. F. A. Dove and J. G. Hallett Chem. Cornm. 1967 571. 2 5 1 K. Rossmanith Monarsh. 1966,97 1698. ’’* D. F. Banks and J. Kleinberg Znorg. Chem. 1967,6 1849. 253 S. J. Lippard H. Nozaki and B. J. Russ Chem. Comm. 1967 118; S. J. Lippard and B.J. Russ, 254 J. M. Pratt and R. J. P. Williams J. Chem. SOC. (A) 1967 1291; J. J. Alexander and H. B. Gray, ”’ A. Ludi H. U. Gudel and V. Dvohik Helv. Chim Acta 1967 SO 2035. 2 5 6 A. A. Vlkk and J. Hanzlik Znorg. Chem. 1967 6 2053; T. Mizuta and T. Kwan J. Chem. SOC. Japan 1966,87 825; T . Mizuta T. Suzuki and T. Kwan J . Chem. SOC. Japan 1967,88 573; M . C Baird G. Hartwell jun. and G. Wilkinson J. Chem. SOC. (A) 1967 2037. Znorg. Chem. 1967,6 1943. J. Amer. Chem. SOC. 1967,89,3356. ’” Articles in Structure and Bonding 1966,l. D. J. Hewkin and A. J. Poe J. Chem. SOC. (A) 1967 1884 310 A. B. Blake J. R. Chipperfield P. G. Nelson and C. F. Stoneman outer-sphere interactions260 are becoming less easy to ignore everywhere, of. conversion of trans-[CoCl en,] + into the cis-isomer by chloride ions in (CH2 CH2)2S02 ;261 the same is true of gaseous complexes262).Discussion of the trans-effect has been much aided by the introduction263 of the term ‘trans-influence’ to describe the tendency of a ligand to weaken the bond trans to itself as measured by 19sPt-31P coupling 264 metal-ligand 266 metal-ligand stretching freq~encies,~~’ etc., but it is still necessary to distinguish the trans-effect proper (i.e. the kinetic effect) and the thermodynamic trans-effect ; this is well illustrated by the necessity to disentangle these in order to understand the substitution of NH3 in trans-[RhX(NH,) en,] + complexes.267 The thermodynamic trans-effect may be considerable the equilibrium constant for the replacement of H 2 0 by CN- in Corn complexes derived from vitamin B12 varies by a factor of at least lo1 as the group trans to it is changed from H 2 0 to CH3*CH;.268 Special Topics.-Five-co-ordination.The number of examples of five-co-ordinate complexes so small not so very long ago continues to rise rapidly. To add to the review mentioned last year summaries have appeared of five-co-ordinate complexes of early transition metalsz6’ and of p~lyamines.~ 70 The stage reached is still very much one of accumulation of examples and the ques-tion of when to expect five-co-ordination and of what geometry to expect, remains for the most part unanswered. There are some ligands that impose five-co-ordination on series of transition-metal ions the terpyridyl complexes [MX terpy] (M = Mn Fe Co or Ni ; X = C1 Br or I) are with one exception, isomorphous with the corresponding Zn compounds which are square pyramidal ;271 9 ’ 7 2 the somewhat similar pyridine-2-carboxaldehyde 2’-pyri-dylhydrazone (paphy) complexes [MX,paphy] (M = Mn Co Ni Cu Zn, Cd or Hg) seem to be square pyramidal except with typical subtlety for nickel and sometimes cobalt ;272 the tridentate Schiff-base complexes [MX,(triL)] (M = Mn Co or Ni) appear to be trigonal bipyramidal;273 the isomorphous compounds [MBr((Me2N*CH2*CH2),N)]Br (M = Cr Mn Fe Co Ni Cu or Zn) are now all known to contain trigonal bipyramidal cations from an X-ray C.H. Langford and W. R. Muir J . Phys. C h m . 1967,71 3602. ”“ V. E. Mironov Russ. Chem. Rev. 1966,35,455; see also rel. 8. ’“ W. R. Fitzgtrald and D. W.Watts J . Amer. Chrm. Soc. 1967,89 821. 262 G. I. Novikov and F. G. Gavryuchenkov Russ. Chem Rev. 1967,36 156. 263 A. Pidcock R. E. Richards and L. M. Venanzi J . Chem SOC. (A) 1966 1707. 264 S. 0. Grim R. L. Keiter and W. McFarlane Inorg. Chem. 1967,6 1133. G. G. Messmer E. L. Amma and J. A. Ibers Inorg. Chem. 1967 6 725. D. A. Langs C. R. Hare and R. G. Little Chem. Comm. 1967 1080. 267 A. J. Poi? and K. Shaw Chem Comm. 1967 52. ”* R. A. Firth H. A. 0. Hill J. M. Pratt R. G. Thorp and R. J. P. Williams Chem. Comm. 1967, 269 G. W. A. Fowles U.S. Government Research and Development Reports 1967,67,49. ”O M. Ciampolini N. Nardi and G. P. Speroni Co-ordination Cheni. Rvi 1966 1 222. ’” J. S. Judge W. M. Reiff G. M. Intille P. Ballway and W. A. Baker jun. J . Inorg. Nuclear ”’ F.Lions I. G. Dance and J. Lewis J . Chem. SOC. (A) 1967 565. 273 L. Sacconi I. Bertini and R. Morassi Inorg. Chem. 1967,6 1548. 400. Chem. 1967,29 1711; J. S. Judge and W. A. Baker jun. Inorg. Chim Acta 1967,1 pp. 239 245 The Transition Elements 311 structure determination of the cobalt while in contrast the corresponding (H,N-CH,-CH,),N complexes of only Co Cu and Zn are five-co-ordinated trigonal bipyramidal.275 Apart from these the new examples of five-co-ordination included in this report involve particular ligands with one or two particular metal ions mostly dipositive ones (though some of these ligands are no doubt capable of eliciting five-co-ordination on a wider scale). Dipositive cobalt complexes of the type [CoX,(triL)] (triL = 2,ddiacetylpyridine dimethylhydraz~ne”~ and (Me,N CH CH2)2S277) are thought to be five-co-ordinate the latter trigonal bipyramidal and solutions of the tetrahedral complexes [Co(RCO CH *CMe*NR‘),] in pyridine are thought to contain five-co-ordinate species when R and R are bulky;278 the crystal structure of [CoCl ((Et2N*CH,-CH,),NH)] discloses a geometry for the complex which is neither trigonal bipyramidal nor square pyramidal and prompts the suggestion that the five-co-ordination is due to steric crowding.279 Several five-co-ordinate phosphorous complexes have also been prepared and charac-terised (see following report) of particular interest is the structure of the [CoCl{(o-Ph,P*C,H,),P)] + ion which does not have the full trigonal (C,) symmetry it could have the Jahn-Teller theorem requires distortion for low-spin trigonal bipyramidal d7 (high-spin [CoBr{ (Me,N*CH CH,),N)] + is C3).280 [triL = (Me2N*CH2 *CH2)2S,277 (2-NCSH4-CHz*CH2),NH, and (2-NC,H,*CH2*CH,)2S ”l] are also thought to be trigonal bipyramidal as is Ni{(NH,*CH2*CH2)2NH)2+ adsorbed on silica X-Ray and spectroscopic studies of high-spin five-co-ordinate complexes with salicylaldimines plus catechol and n.m.r.studies of such complexes with quinquedentate Schiff bases point to distorted trigonal bipyramidal co-ordination of the nickel atoms in these complexes,283 while the low-spin cation [Ni(CN){(Me,As*CH,*CH,*CH,),P)]+ has been found by X-ray crystallography to approximate closely to C3 Several other five-co-ordinate complexes containing M-P etc. bonds have been pre-pared including a few of dipositive palladium (see following report).In the case of dipositive copper reports of the preparation and characterisa-Dipositive nickel complexes of the type [NiX,(triL)] 274 M. Di Vaira and P. L. Orioli Inorg. Chem. 1967,6,955. 27s M. Campolini and P. Paoletti Inorg. Chem. 1967,6 1261. 276 J. D. Curry M. A. Robinson and D. H. Busch Inorg. Chem. 1967,6 1570. 2’7 M. Campolini and J. Gelsomini Inorg. Chem. 1967,6 1821. 278 S. Yamada and E. Yoshida all. Chem SOC. Japan 1967,40 1854. 279 Zvi Dori R. Eisenberg and H. B. Gray Inorg. Chem. 1967,6,483. T. L. Blundell H. M. Powell and L. M. Venanzi Chem. Comm. 1967 763. 281 S. M. Nelson and J. Rodgers Inorg. Chem. 1967,6 1390. B. J. Hathaway and C. E. Lewis Chem Comm. 1967 504.283 L. Sacconi P. L. Orioli and M. Di Vaira Chem Comm. 1967 849; G. N. La Mar and 284 D. L. Stevenson and L. F. Dahl J . Amer. Chem SOC. 1967,89 3424. L. Sacconi J . Amer. Chem SOC. 1967,89 2282 312 A. B. Blake J . R. Chipperfield P. G. Nelson and C. F . Stoneman tion of both trigonal bipyramidal and square-pyramidal complexes continue to appear. X-Ray crystallography has established trigonal bipyramidal co-ordination in [Cu40C1,(Ph3PO),] [Cu(NCS)((H,N*CH,* CH,),N}]SCN, and [ CuCl,(H OXbiL)] (biL = 2,9-dimethyl- 1,lO-phenan throline) whereas [MCl,(biL)] are tetrahedral (M = Fe Co Ni or Zn).285 Square-pyramidal co-ordination has been established in [Cu acac,(quinoline)] complexes derived from pyridoxal (see biological section) histidines and N-salicylideneglycine and [CuC1,(4-NC5H4*Me),] (unlike six-co-ordinated [CuCl py,]) which contains square pyramids sharing an apical edge to form a rectangular four-membered bridge a square-pyramidal arrangement which is becoming quite common.286 The following are thought to be five-co-ordinate [CuC12(triL)] (triL = 2,6-diacetylpyridine dimethyl-hydrazone) ;276 [CuX(quadriL)]+ CquadriL = ethylenebis(8-quinolylmethyl-eneimine)] ; [CuX(biL),] + (biL = perhydrodiazepine); [CuL5I2 + (L = 2,3-dimethyl- l-phenyl-3-pyrazolin-5-one) ; and [C~acac,(4-MeC,H,N0)].~~~ X-Ray crystallography reveals approximate trigonal bipyramidal geometry in the dipositive zinc compounds [Zn(S,CNMe2)py] and [Znacac2I3; the latter contains one octahedral and two trigonal bipyramidal zinc atoms and is a suitably curious addition to the dipositive acetylacetonate structures already known i.e.those of [Ni acac2l3 and [Co a ~ a c ] ~ . ~ ~ ~ Five-co-ordinate adducts are reported to be present in pyridine solutions of N-alkylsalicylaldiminate complexes [Zn(biX),] when the alkyl is methyl or ethyl but not higher and in pyridine solutions of the Schiff-base complexes [Zn(quadriX”)] formed from salicylaldehyde and H2N*[CH,];NH2 when n = 2-3 but not 4-9 (the same two solid complexes also appear to be five-co-ordinate through oxygen bridging) this shows how much the stereochemistry of zinc at least is deter-mined by steric factor^.^ 89 X-Ray crystallography discloses trigonal bipyra-midal co-ordination of mercury in [ HgC1,L) (L = 2,4,6-trimethylpyridine) and square-pyramidal in [HgCI,(RO)] with an axial-oxygen bridge (RO = cis-4-(pchloropheny1)thiane oxide).290 28s J.A. Bertrand Inorg. Chem. 1967 6 495; P. C. Jain and E. C. Lingafelter J . Amer. Chem. Soc. 1967,89 724; H. S. Preston and C. H. L. Kennard Chem. Comm. 1967 1167. 286 (a) S. Scavnicar and B. Matkovic Chem Comm. 1967 297; (b) S. Ooi and Q. Fernando ibid., p. 532; (c) J. E. Cutfield D. Hall and T. N. Waters ibid. p. 785; (d) J. F. Blount K. A. Frazer H. C. Freeman J. T. Szymanski and C.-H. Wan& Acta Cryst. 1967 22 396; (e) H. C. Freeman and J. T. Szymanski ibid. p. 406; v) T. Ueki T. Ashida Y. Sasada and M. Kakudo ibid. p. 870; (9) V . F. Duckworth D. P. Graddon N. C. Stephenson and E. C. Watton Inorg. Nuclear Chem. Letters, 1967,3 557. 287 J. Dekkers and H. A. Goodwin Austral.J . Chem. 1966 19 2241; W. K. Musker and M. S. Hussain Inorg. Nuclear Chem. Letters 1967 3 271 ; J. Gopalakrishnan A. Ravi and C. C. Patel, aUl1. Chem SOC. Japan 1967 40 791; R. W. Kluiber and W. Dew. Horrocks jun. Inorg. Chem., 1967,6 1427. 288 K. A. Fraser and M. M. Harding Acta Cryst. 1967 22 75; M. J. Bennett F. A. Cotton, R. Eiss and R. C. Elder Nature 1967,213 174. G. E. Batley and D. P. Graddon Austral. J . Chem. 1967 20 877 885. 290 S. Kulpe 2. anorg. Chem. 1967,349,314; R. S. McEwen G. A. Sim and C. R. Johnson Chem. Comm. 1967,885 The Transition Elements 31 3 The preparation and characterisation of tripositive trigonal bipyramidal complexes of titanium vanadium and chromium of the type [MX,Lz] (X = C1 or Br) have been extended; of particular note is the conclusion (based on magnetic measurements and partly on X-ray crystallography) that the titanium and chromium complexes deviate from D S h symmetry but the vanadium ones do not because the ground state of only V3+ is an orbital singlet in 0 3 h .2 9 1 Further examples of square-pyramidal tripositive iron have been established by X-ray crystallography viz. in [FeCl(quadriX")],CH,NO, and [ FeCl(quadriXii)12 [quadriX" = NN'-ethylenebis(salicylideneiminate)], and in low-spin [Fe{ S2C2(CN)2}2]22- the last two with axial-atom bridges, and it has been suggested that five-co-ordination might be a reasonably favourable stereochemistry for iron(111).~~~ The magnetic properties of the square-pyramidal complexes [FeX(S2CNR2)2] were mentioned under Iron.Five-co-ordinate compounds of VIV Mo"' Re''' ReV and Au"' were re-ported under the appropriate elements. High co-ordination numbers. The many new examples of complexes involving co-ordination numbers greater than six have already been described. It only remains to mention a review of the whole subjectzg3 and two reviews of eight-c o - ~ r d i n a t i o n ~ ~ ~ and to report that the present theoretical position on the question of whether the observed geometries are determined by the metals or the ligands is rather confusing.z95 Optical stereochemistry. Considerable attention has been given to the preparation of optically active co-ordination compounds and the determina-tion of their absolute configuration and to stereospecific reactions. Progress in the area has been well covered by reviews.296 Empirical rules have been further developed for the assignment of the absolute configuration of complexes from their optical rotatory dispersion spectra by comparison with those of a similar compound and these have been applied to inter alia amino-acid complexes of c o b a l t ( ~ ~ ~ ) .~ ~ ' It has been shown that empirical and non-empirical optical methods of assignment are mutually consistent and for (-)-[Fe phen3I2+ correct.z98 Comparative assignment by 291 M. W. Duckworth G. W. A. Fowles and P. T. Greene J . Chem SOC. (A) 1967 1592; G. W. A. 292 M. Gerloch and F. E. Mabbs J . Chem. SOC. (A) 1967 pp. 1598 1900; W. C. Hamilton and 293 E. L. Muetterties and C. M. Wright Quart. Rev. 1967 21 109. 294 R. V. Parish Co-ordination Chem Rev.1966 1,439; S. J. Lippard Progr. Inorg. Chem. 1967, 8 109. 295 S. F. A. Kettle Co-ordination Chem Rev. 1967 2 9; R. V. Parish and P. G. Perkins J . Chem. SOC. (A) 1967 345; S. F. A. Kettle and A. J. Smith ibid. p. 688. 296 J. H. Dunlop and R. D. Gillard Ado. Inorg. Chem Radiochem. 1966 9 185; R. D. Gillard, Progr. Inorg. Chem. 1966,7 215; G. V. Panova E. G. Rukhadze and A. P. Terent'ev Russ. Chem. Rev. 1966 35 687; A. M. Sargeson Transition Metal Chem. 1966 3 303; R. D. Gillard Chem. in Biitain 1967,3 205. 297 K. Garbett and R. D. Gillard Co-ordination Chem. Rev. 1966 1 179; R. D. Gillard Proc. Roy. SOC. 1967 A 297 134; R. D. Gillard Nature 1967 214 pp. 168 1007; R. D. Gillard P. M. Harrison and E. D. McKenzie J . Chem. SOC. (A) 1967,618. Fowles P.T. Greene and J. S. Wood Chem Comm. 1967,971. and I. Bernal Inorg. Chem. 1967,6 2003. 298 S. F. Mason and B. J. Norman Inorg. Nuclear Chem. Letters 1967,3 285 314 A. B. Blake J. R. Chipperfield P. G. Nelson and C. F. Stoneman means of 'H n.m.r. spectroscopy has been introduced and used; this technique makes e.g. the same assignment for ( +)5,,-Na[Coox {( -)-pn}] as does the optical method.2" The absolute configuration of the ( + )58,-trans-[CoCl,{(H,N*CH *CH,),N)] ion has been determined the dissymmetry of which arises from the asymmetry of the co-ordinated secondary nitrogen of the ligand and from the chelate ring configurations which are dependent upon the particular orientation of the secondary N-H bonds.300 The complex [Co(quadriXii)(( -)-pn}] + has been separated into six isomers by ion-exchange thought to be essentially diastereomeric trans- cis- and cis'-pairs, the two cis-forms arising from different orientations of the propylenediamine The cations [MN{Co(H2N-CH,*CH,*S),),]N+ (MN = Co" or Zn") have been resolved and it appears that in the homonuclear complex the terminal and central cobalt atoms have opposite absolute configuration^.^^^ Many more examples of stereospecific reactions have been reported.It has been found that L-glutamic acid reacts more quickly with D-[CO(H,O) en2], than with the L- form this stereospecificity is attributed to the favourable interaction of the y-carboxy-group of the glutamic acid with the amino-group of the eth~lenediamine.~'~ It has also been found that peptides containing a C-terminal amino-acid of the L-configuration give preferentially the L-configuration at cobalt when they react with [Co(OH)(H20)en,l2+ whatever the N-terminal amino-acid this emphasises the possibilities of simple metal-complexes as models for the much more complicated enzymic systems.304 The reaction of ~-cis-a-[CoCl,(quadriL)] + [quadriL = L,L-~,~'-(NH - CHMe NH CH,),] with a-amino-acids gives ~-cis-a-[Co(biX)(quadriL)]~ + with retention of configuration whereas aquation (shown to go with retention of configuration) followed by reaction with the a-aminoaid gives ~-cis-~-[Co(biX)(quadriL)]~ + with inversion.,05 And the reaction of ( +)450-[PtC12 en,]Cl and ethyl-enediamine at room temperature yields optically pure D-[Pt en3]C1,.306 The first example of stereoselective isomerism has been reported three forms of solid bis-(DL-phenylalaninato)copper@) could be obtained but only one form of the corresponding L-compound 'under all condition^'.^^' It has been found that stereospecificity is only slight for the reaction between a-[CoCl, 299 R.G. Asperger and C. F. Liu J . Amer. Chem SOC. 1967,8!l 708; J. G. Brushmiller and L. G. Stadtherr Inorg. Nuclear Chem. Letters 1967 3 525; D. A. Buckingham L. Durham and A. M. Sargeson Austral. J . Chem. 1967,20 257; J. I. Leg& D. W. Cooke and B. E. Douglas Inorg. Chem., 1967,6,700. '0° D. A. Buckingham P. A. Marzilli A. M. Sargeson S. F. Mason and P. G. Beddoe Chem. Gomm 1967,433. 30' J I. Legg. Chem Comm. 1967 675. '02 G. R. Brubaker and B. E. Douglas Inorg. Chem. 1967,6 1562.'O' J. H. Dunlop R. D. Gillard and N. C. Payne J . Chem. SOC. (A) 1967 1469. 304 D. E. Allen and R. D. Gillard Chem. Comm. 1967 1091. 305 R. G. Asperger and C. F. Liu J . Amer. Chem. SOC. 1967,89 1534. jo6 C. F. Liu and J. Doyle Chem. Comm. 1967,412. 'O' S. H. Laurie Chem. Comm. 1967,155 The Transition Elements 315 trien] + and propylenediamine to give p-[Co pn trien13 +. (and that the optical activity of the product is determined almost entirely by the arrangement of the chelate rings).308 The solvent ~-2,3-butane-diol has been used for carrying out asymmetric syntheses and transformations ; thus e.g. racemic cis-[CoCl en,] + isomerises to an equilibrium mixture containing about 80 % trans and more of one cis enantiomer than the other.309 Systems of biological interest.Much effort has been expended on the quest for an understanding of the role of transition metals in the intricate biological reactions which occur in vivo. This report of work published in chemical journals only hints at the progress in this field. Reviews have appeared on ferredoxin and other naturally occurring non-haem iron cornpo~nds,~ lo and on transition-metal ions as reagents in metallo-en~ymes.~ '' 7 The important transamination reaction that is involved in in uivo catalysis of amino-acid reactions by enzymes with the coenzyme vitamin B6 [RCH2-OH with R = (7)] whereby a CO group is converted into a CH-NH group has been further studied it has been found that the zinc chelate of pyridoxamine, RCH2*NH2 reacts with Me2CH*CO.CO2H to give the zinc chelate of the Schiff-base RCH -N:C(CO,H)*CHMe, which rearranges to the chelate of the Schiff-base RCH N - CH(C0 H) - CHMe,(I)derived frompyridoxal RCHO, and valine Me,CH-CH(NH,)*CO,H which is the first example of this for zinc;312 both of the analogous copper chelates derived from salicylamine and MeCO C02H and from salicylaldehyde and a-alanine,MeCH(NH,)- C02H, have been isolated (and called 'fused chelate ring isomers') :3 and the copper complex of (I) has been found to have a square-pyramidal structure and the essential planarity thought to be necessary in facilitating the reactions of the coenzyme confirming that a primary function of the metal ion is to define and stabilise the required pathway in a steric sense.286c It has been discovered that RCO*COR (R = 2-pyridyl) reacts with hydrated cobalt or nickel acetates in methanol to form six-co-ordinate complexes of R,C(OI3)-CO2- a rearrangement which only otherwise occurs in boiling sodium methoxide solution.This type of reaction is of great importance in enzymic systems but this is the first example in vitro of a molecular rearrange-ment involving group migration effected by a metal template.314 308 E. Kyuno and J. C. Bailar jun. J . Amer. Chem SOC. 1966,88 5447. 309 B. Bosnich J . Amer. Chem. SOC. 1967,89 6143. 310 J. B. Neilands Structure and Bonding 1966 1 59; B. B. Buchanan ibid. p. 109. " A. E. Dennard and R. J. P. Williams Transition M e t a l Chem. 1966 2 1 16. 312 Y. Matsushima and A. E. Martell J . Amer. Chem. SOC. 1967,89 1331. 313 Y. Nakao S.Sasaki K. Sakurai and A. Nakahara MI. Chem SOC. Japan 1967,40,241 '14 D. St. C. Black Chem. Comm. 1967 31 316 A. B. Blake J . R. Chipper$eld P . G. Nelson and C . F . Stoneman Cobalt(m) complexes have been used as catalysts in the synthesis and hydrolysis of peptides. Both [CoCl(H,N CHI C0,Et) trien] + and [Co(H,N*CH *CO,Et) trien13 + react with H2N* CH2 *CO,Et rapidly and almost quantitatively to give [Co(H,N.CH -CO-NH-CH2-C02Et)trien]3+, and in this way can be used to link glycine to a variety of amino-acid and peptide esters; I4C labelling experiments confirm that the reaction takes place on the ~ o b a l t . ~ P-[Co(OH)(H,O) trien]’ + reacts with peptides amino-acid esters and amino-acid amides hydrolysing them and leaving the N-terminal amino-acid residue co-ordinated to the meta1.j l6 A stereospecific hydrolysis of biological interest was mentioned under Optical stereochemistry.Linear tetrapyrroles have been converted into tetradehydrocorrins and porphins as nickel complexes recalling the biogeneses of the porphins and cobalamins from pyrrolic precursors. 317 Extended Hiickel calculations on porphin complexes of iron predict that N will not be bound by Fe”’ porphins, and that 0 will only be bound if it is not perpendicular to the plane of the rings. Contact shifts. Some use of these has been made this year and the stage reached in their application is well illustrated by the following examples. Those in the ‘H n.m.r. spectrum of [Ni(triL),12+ where triL is the nitrogen macrocycle tribenz0Cbfj-J-[ 1,5,9]triazacycloduodecine have been taken to indicate spin-transfer into ligand A-orbitals which is inconsistent with D3d symmetry and suggests a propellor-like distortion of the three benzene rings ;3 l9 those of the proton resonances in the complexes [V(RCO-CR’*COR”),] and [V{ RCO CH C(NR)R”} 3] have also been taken to indicate delocalisation into ligand ~ r - o r b i t a l s .~ ~ ~ Delocalisation of unpaired spin into the phenyl n-systems of N-substituted anilines co-ordinated to Ni acac, and of benzylamine in [Ni(PhCH -NH2)6]2+ has been observed thus providing a warning against the assumption that n-type delocalisation automatically implies metal-ligand n-bonding the Ni-N bonding orbital in these compounds though o is not necessarily orthogonal to the rorbitals of the aromatic ligand~.~’’ Electronic Properties.-Reviews have appeared on the electronic structures of square-planar complexes,32 electron spin resonance spectra of transition-metal e o m p l e ~ e s ~ ~ ~ ~ and electronic properties of binary compounds of metals of the first series3 The use of molecular-orbital theory to interpret electronic spectra was the theme of a number of investigations with some attention being paid to band 315 D.A. Buckingham L. G. Marzilli and A. M. Sargeson J . Amer. Chem. SOC. 1967 89 2772, 4539. 316 D. A. Buckingham J. P. Collman D. A. R. Happer and L. G. Marzilli J . Amer. Chem SOC., 1967,89 1082; cf. D. A. Buckingham and J. P. Collman Znorg. Chem. 1967,6 1803. jl’ I. D. Dicker. D. Dolphin R. Grigg and A. W. Johnson. Chem. Cornrn. 1967.560. 3’8 M. Zerner M. Gouterman. and H Koh;ivashi. Thror. Chm. Actrr. 1966. 6. 363 31y G. N. La Mar Inorg. Chem. 1967,6 1921. 320 F. Rohrscheid R. E. Emst and R. H. Holm Znorg. Chem. 1967,6,1315,1607. R W. Kluiber and W. Dew. Horrocks jun. Inorq. Chem 1967 6. 430 R. J. Fitzgerald and R. S. Drago J . Amer. Chem SOC. 1967,89 2879. 322 (a) H. B. Gray Transition Metd Chem 1965 1 240 (b) B. R. McGarvey. hid 1966. 3 90 The Trunsition Elements 317 intensities. The question of the intensities of d-d transitions in relation to 'borrowing' from charge-transfer transitions has been pursued and it has been concluded that the final state of the charge-transfer transition must involve metal eg but not metal tzg orbitals.323 A theoretical treatment of the charge-transfer bands in phenanthroline complexes of Fe" Fern and Cu' has led to the suggestion that 'the main source of intensity is the transition moment resulting from the transfer of charge itself'.324 The intense absorption often associated with mixed oxidation states has been in mixed crystals of the orange compounds [C0(NH3)6]CU"CIs and [CO(NH,)~],CU:C~, the brown to black colour is due to a Cun t Cu' charge-transfer transition at about 17,000 cm.-'.Differences in the electronic absorption spectra of salts containing the [CuC1,J2 - ion in its square-planar and distorted tetrahedral forms have been investigated,326 and a comparison of these with spectra of salts containing the [CU,C~,]~- ion has produced the suggestion that a band at about 19,OOO cm.-' is diagnostic of dinuclear Cuu c0mp1exes.l~~ On the other hand the controversial band at about 28,000 cm.-l in the absorption spectrum of Cu,(OAc) has now been assigned to charge-transfer involving the bridging 'n' system rather than to an internal d-d transition of the Cu, moiety.327 Successful application of the more restricted crystal-field approach to lower-symmetry complexes has continued.The electronic spectra of [NiCl py,] and [NiBr py4]328 and of salts containing the ions [Cr(CN),(H,0)6 -J3-, (n = 0-6),3'9 have enabled full sets of the parameters B C Dq Ds and Dt to be obtained and criteria for distinguishing between cis- and trans-isomers of octahedral d3 complexes to be deduced. An investigation has been made of the utility of magnetic optical activity in the study of d-d transitions; magnetic circular dichroism dispersion seems particularly promising for the location of electric-dipole forbidden transition^.^ 30 Luminescence spectra have been the subject of many papers in the more physical journals; of particular interest is the observation of a correlation between luminescence behaviour and ligand-field strength in a series of Crrn complexes for which an explanation has been ~ffered.~ ' As usual as little progress has been made with the task of rationalising energetics of a more chemical significance as with anything.Indeed empirical octahedral and tetrahedral site-preference energies have now been obtained for various metal ions in spinels on the basis of purely statistical preference 3 2 3 R . L. Belford and J. W. Carmichael.jun J . Chrm. Phjn 1967.46.451 5 R. F Fenske. J . Amrr. 324 P. Day and N. Sanders J . Chem. SOC. (A) 1967 pp. 1530 1536. 325 P. Day and D. W. Smith J . Chem. Sac. (A) 1967 1045. 326 R. D. Willett 0. L. Liles jun. and C. Michelson Znorg. Chem. 1967,6 1885. 327 L. Dubicki and R. L. Martin Znorg. Chem. 1966,5,2203. 328 D. A. Rowley and R. S. Drago Znorg. Chem. 1967,6 1092. 329 R. Krishnamurthy W. B. Schaap and J. R. Perumareddi Znorg. Chem. 1967,6 1338. 330 A. J. McCaffery P. J. Stephens and P. N. Schatz Znorg. Chem. 1967,6 1614. 331 H. L. Schlafer H. Gausmann and H. Witzke J . Chem. Phys. 1967,46 1423. Chem. SOC. 1967,89,252 318 A. B. Blake J . R. Chipperfield P . G . Nelson and C. F . Stoneman entropies and while these agree qualitatively with the predictions of ligand-field theory there are substantial quantitative Magnetism.Work has continued on the detailed interpretation of magnetic behaviour in magnetically dilute systems by means of ligand-field theory. The susceptibilities (80-300"~) of approximately octahedral V'" complexes, and of salts of the ions VC1,'- and VOCI,'- have been compared with the theory for 3T1g and 'Tze ground terms respectively perturbed by spin-orbit coupling and an axial distortion of the ligand field with the orbital reduction factor as an additional parameter.333 The theory for 5T2g ground terms in the presence of a trigonal or tetragonal ligand field has been worked out and applied to a number of Fen complexes.334 The observed susceptibilities of some six-co-ordinate Ru" and Osm complexes can be fitted with a wide range of the axial-field spin-orbit coupling and orbital-reduction parameters, emphasising the need for caution with this kind of interpretation and the desirability of direct measurements of magnetic ani~otropy.~~' The magnetic properties of di- and poly-nuclear complexes continue to attract interest and as in previous years much of this has been concerned with copper@).The interpretation of the magnetic properties of complexes [ { Fe(quadriX")] 20] and [ { Fe(quinqueX"')] 20]2 - in terms of the presence of a linear Fe-0-Fe system has already been mentioned under iron; the interpretations differ however the susceptibility-temperature data of the former were interpreted in terms of strong antiferromagnetic exchange between high-spin (S = 5/2) iron while the room-temperature moment of the latter (2.9 B.M.) was interpreted by a molecular-orbital treat-ment which predicts the presence of two unpaired electrons;133 it would be interesting to know how the susceptibility of the latter varies with temperature.Compounds in which metal complexes of NN'-ethylenebis(salicy1ideneiminate) and related species are themselves acting as ligands have been found to be admirable systems for the study of exchange interactions; e.g. complexes of the type [{C~(quadriX")),M]~+ (M = Cu Ni or Zn) can be prepared the magnetic properties of which indicate spin coupling between the two outer metal ions as well as between inner and outer.336 The first examples in which the exchange interaction in a polynuclear complex appears to be ferromagnetic rather than antiferromagnetic have been reported in compounds having M-0-M bridging angles of approximately 90° a situation for which ferro-magnetic exchange had been predicted for d8 ions the compounds are [Nia~ac,],,~~' and [M[M~OXO-O.C~H~*CHO)(ROH)]~ (M = Ni or Co; R = Me or Et).338 Such then displayed as well as we have been able is the progress of our fo 1 ibu nda. 332 A. Navrotsky and 0. J. Kleppa J . Inorg. NucEear Chem. 1967,29 2701. 333 D. J. Machin and K. S. Murray J . Chem SOC. (A) 1967,1330,1498. 334 B. N. Figgis J. Lewis F. E. Mabbs and G. A. Webb J . Chem. SOC. (A) 1967,442. 335 J. Lewis F. E. Mabbs and R. A. Walton J . Chem. SOC. (A) 1967 1366. 336 S. J. Gruber C. M. Harris and E. Sinn Znorg. Nuclear Chem. Letters 1967 3 495. 337 A. P. Ginsberg R. L. Martin and R. C. Sherwood Chem. Comm. 1967 856. 338 J. E. Andrew and A. B. Blake Chem Comm. 1967 1174

ISSN:0069-3022    

DOI:10.1039/GR9676400283

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

13. TRANSITION-METAL CARBONYLS AND ORGANOMETALLIC COMPLEXES By J. A. McGinnety and M. J. Mays (University Chemical Laboratory Lensfield Road Cambridge) THE division of topics between this review and the previous one is not clear-cut. To avoid repetition we have made some arbitrary divisions and while phos-phine complexes molecular oxygen complexes and molecular nitrogen adducts are dealt with cyanide complexes are included only if they contain other organic ligands. To us the most interesting work reported during 1967 has been that on molecular nitrogen adducts; it seems likely that there will be new developments in this area during 1968. Reviews have been published on the following topics the structural chemistry of organo-transition-metal complexes ;’ insertion reactions involving un-saturated substrates ;’ olefin oxidation with palladium(r1) catalysts in solution ;3 cyclobutadiene metal compounds ;4 mass spectra of organometallic com-pounds.’ Volume 2 of the ‘Annual Surveys of Organometallic Chemistry’ covering the year 1966 has been published;6 also a book on organometallic chemistry for the non-~pecialist.~ A volume in the ‘Advances in Chemistry’ series a tribute to Alfred Werner contains reviews of current research in complex chemistry as well as historical articles.’ The first volume of ‘Per-spectives in Structural Chemistry’ includes a review on ‘lt-complexes of Transition Metals with Aromatic Systems.” Carbonyls.-(a) Mononuclear.Most of the work in this area has been concerned with the accumulation and interpretation of spectroscopic and kinetic data.The existence of pentacarbonylrutheniurn and pentacarbonyl-osmium has been confirmed and their i.r. spectra in the carbonyl stretching region recorded. lo The results of an electron diffraction study on pentacarbonyl iron which indicated that the Fe-C axial bonds are shorter than the M. R. Churchill and R. Mason Adv. Organometallic Chem. 1967,5,93. A. Aguil6 Adv. Organometallic Chem. 1967,5 321. M. P. Cava and M. J. Mitchell ‘Cyclobutadiene and Related Compounds,’ Academic Press, H. Budzikiewicz C. Djerassi and D. H. Williams ‘Mass Spectrometry of Organic Com-D. Seyferth and R. B. King Ann. Survey Organometallic Chem. 1966 2. ’ P. L. Pauson ‘Organometallic Chemistry,’ Arnold London 1967. ‘Advances in Chemistry Series,’ vol.62 Amer. Chem. Soc. 1967. J. D. Dunitz and J. A. Ibers ‘Perspectives in Structural Chemistry,’ Wiley New York 1967. lo F. Calderauo and F. L.’Eplattenier Znorg. Chem. 1967 6 1220. ’ M. F. Lappert and B. Prokai Adv. Organometallic Chem. 1967,5,225. London 1967. pounds,’ Holden-Day San Francisco 1967. 320 J . A. McGinnety and M . J . Mays equatorial' bonds has been further criticised.12 More experimental work is in progress by the original author^.'^ The mass spectra and appearance potentials for the major ions from a number of binary metal carbonyls M(CO), (M = Ni Fe Cr Mo W and V) have been measured. From the data the mean vanadium-carbon bonddissociation energy in V(CO)6 is estimated as 28 kcal./mole. l4 The molecular-beam mass spectrum of tetracarbonylnickel provides no evidence for the existence of gas-phase intermediates such as Ni(CO) in a low-pressure flow reactor.The mean N i x bond dissociation energy from appearance potential data is 39.3 + 1.0 k~al./mole.'~ The kinetics of Ni(CO) formation from metallic nickel and carbon monoxide at 90-400"~, together with the sensitizing effect of H2S on this reaction have been studied.I6 The activation energy for the thermal decomposition of Cr(CO)6 at 195-220" and of Mn2(CO)lo at 24&-310" are 4.25 and 16-15 kcal./mole respectively. Both reactions are first order." The magnitude of the Faraday effect has been measured for Ni(C0)4 and Fe(CO),.'* The i.r. spectra of metal carbonyls continue to attract much attention. The effect of solvent on the i.r. spectra of M(CO)6 (M = Cr Mo or W) has been investigated in the range 2100-70 cm.-' in all cases v(C0) in solution is lower than in the vapour state (vvap.- vsa,. = 7-25 crn.-') while by com-parison 6 (M-C-0) is almost solvent independent." Anharmonic correc-tions for the CO stretching vibrations of Ni(C0)4 have been calculated" and it has been shown that ignoring such corrections can lead to considerable differences in calculated force constants. ' The low-frequency vibrational fundamentals of Ni(C0)4 have been reassigned from a study of the gas-phase i.r. and Raman spectrum below 100 cm.-1.22 Although the Cotton-Kraihanzel model for calculating approximate force constants23 is useful in certain circumstances the quantitative significance of approximate force constants has probably been o~eremphasised.~~ The values of the CO-CO interaction constants can be particularly misleading.2 ' An alternative simplified treatment has been proposed which assumes that the effects of ligands on force constants are additive.25 l 1 M.I. Davis and H. P. Hanson J . Phys. Chem. 1965,69 3405. l 2 J. Donohue and A. Caron J . Phys. Chem. 1967,71,777. " M. 1. Davies J . Phys. Chem. 1967 71 775. l4 D. R. Bidinosti and N. S. McIntyre Cunad. J . Chem. 1967,45,641. l6 G. Heinicke H. Harem and K. Sigrist 2. anorg. Chem. 1967,352 168. S. M. Schildcrout G. A. Pressley and F. E. Stafford J . Amer. Chem. SOC. 1967,89 1617. l7 L. D. Segal 0. D. Krechevskaya N. A. Belozerskii N. E. Kolobova and K. N. Anisomov, '* F. Gallais and H. Haraldsen Compr. rend. 1967 264 1.l9 R. J. H. Clark and B. Crociani Znorg. Chim Act% 1967,1 12. 2o L. H. Jones J . Chem Phys. 1967,47 1196. 21 L. H. Jones Znorg. Chem. 1967,6 1269. 22 L. H. Jones J. Chem Phys. 1967,46 1536. 23 F. A. Cotton and C. S. Kraihanzel J . Amer. Chem SOC. 1962,84,4432. 24 L. M. Bower and M. H. B. Stiddard Znorg. Chim. Acta 1967,1,231. " H. Haas and R. K. Sheline J . Chem Phys. 1967,47,2996. Zhur. neorg. Khim. 1967,12 1118 Transition-M eta1 Carbonyls and Organometallic Complexes 321 (b) Polynuclear. The recoil behaviour of ’,Mn in dilute solutions of Mn,(CO), has been studied., Measurement of appearance potentials for ions derived from Mn,(CO),, Re,(CO)lo and ReMn(CO)* have been made; the relative order of metal-metal bond dissociation energies in the carbonyls is ReMn > ReRe > MnMn;27 approximate force constants cal-culated from Raman data were in the same order.28 The absolute value for Mn,(CO)lo however differs considerably from that obtained in a previous calorimetric study.,’ A value of 11.5 + 0.5 kcal.has also been determined for the Co-Co bond energy in octacarbonyldicobalt by mass spectros~opy.~~ Reaction of NaM(CO) with M’(CO) affords the six new anions [(CO),M-M’(CO),]- (M = Mn or Re; M’ = Cr Mo or W). These were isolated as their tetraethylammonium salts. An i.r. study indicates that they are isostructural with Mn,(CO)lo.3 Interest in polynuclear metal carbonyls has been stimulated by faster X-ray determinations of structure and the greater availability of mass spectrometers. Irradiation of a solution of Fe(CO), and Re,(CO)lo yields the new polynuclear carbonyls Re2Fe(CO)1 and [ReFe,(CO),,]-.The structure of the latter is probably similar to that of Fe3(C0)12 with the Fe(CO) group replaced by Re(CO)i.32 Reduction of Re,(CO), with sodium borohydride gives a red solution which probably contains several different polynuclear species. One of these Re,(CO):, has been isolated as its tetrabutylammonium salt and X-ray crystallographic analysis shows that the rhenium atom skeleton consists of two fused approxi-mately equilateral triangles with all four atoms in a plane. Each rhenium is associated with four CO ligands two of which are axial and two equatorial. Acidification gives a new polynuclear carbonyl hydride which has not yet been ~haracterised.~~ Details of the preparation of [Ru(CO),13 from ruthenium chloride with zinc in methanol under low carbon monoxide pressures (10 atm.) have been p~blished.~ A method for the synthesis of [0s(CO),I3 in high yield has also been de~cribed.~’ These two carbonyls react with stoicheiometric quantities of tertiary phosphines giving [M(CO),L] complexes.35* 36 Heating [Ru(CO),] in benzene gives a red crystalline complex which has been formulated as RU,(C0)18 on the basis of analysis and its molecular weight in solution.37 This complex may be identical with Ru6(CO),,C a ruthenium carbonyl carbide which together with Ru,(CO),,C(arene) [arene = MeC6Hsr Me,C,H, Me3C6H3] has been prepared by a very similar method 26 U.Zahn Radiochim. Acta 1967 7 170. 2’ H. J. Svec and G. A. Junk J .Amer. Chem. SOC. 1967,89,2836. ” H. M. Gager J. Lewis and M. J. Ware Chem. Comm. 1966 616; D. R. Bidinosti and N. S. 29 F. A. Cotton and K. R. Monchamp J . Chem. SOC. 1960,533. ’O D. R. Bidinosti and N. S. McIntyre Chem. Comm. 1967 1. ’’ U. Anders and W. A. G. Graham J . Amer. Chem. SOC. 1967,89 539. ” G. 0. Evans J. P. Hargaden and R. K. Sheline Chem. Comm. 1967 186. ’’ R. Bau B. Fontal H. D. Kaesz and M. R Churchill J. Amer. Chem. SOC. 1967,89 6374. 34 M. I. Bruce and F. G. A. Stone J . Chem. SOC. (A) 1967 1238. ” C. W. Bradford and R. S. Nyholm Chem. Comm. 1967,384. 36 F. Piacenti M. Bianchi E. Renedetti and G. Sbrana J . Inorg. Nuclear Chem. 1967 29 1389. ”I F. Piacenti M. Bianchi and E. Benedetti Chem. Comm. 1967 775. McIntyre ibid. p. 555 322 J . A. M cGinnety anJ M .J . Mays and characterised as a carbide by mass spectro~copy.~~ Although it has been suggested that the structure of C O ~ ( C O ) ~ ~ may not be the same in solution as in the solid state the observation of two resonances in the "Co n.m.r. spectrum of the complex in n-hexane solution supports the CJV structure found in the solid.,' The crystal structure of Rh4(CO),2 is similar to that of CO~(CO)~ ; bridging CO groups and metal-metal bonds link the three basal rhodium atoms of the tetrahedral cluster while in Ir4(CO)12 the tetrahedron is held together entirely by metal-metal bonds4' New cobalt cluster com-pounds to be reported include [co6(co)14]4- [co6(co)15]2- and CO,(CO),,.~' Methods have been found for the synthesis of Rh,(C0),6 and Ir4(CO)12 in high yield;42 the electronic structure of Rh,(CO), has been discussed.43 Heating Ir4(CO)12 with methanolic potassium hydroxide gives a dark solution from which on addition of trimethylbenzylammonium chloride (tba) a brown crystalline product formulated as [tba]2[Ir4(CO)lo]2 was Treatment of this anion with triphenylphosphine gives Ir4(C0)9(PPh,) ; an X-ray determination shows this complex to contain an iridium-atom tetrahedron in which the three basal atoms are bridged by carbonyl groups and are linked to an apical Ir(CO) by metal-metal bonds only.Each basal iridium is co-ordinated by one triphenylphosphine ligand.45 (c) Carbonyl hulides. As with with monomeric carbonyls the relative simplicity of the monomeric carbonyl halides has encouraged investigations of the spectroscopic properties of these molecules.1.r. and Raman data have now been obtained for Re(C0)J and Re,(CO), which enable a complete assignment of their vibrational spectra to be made. This is the first such treatment for a metal carbonyl halide.46 The CO stretching vibrations for Mn(CO)5X molecules have been further studied. Peaks due to Mn(C0)4(13CO)X have been assigned for X = CH, CF, H and Br and the data obtained used to check previous frequency-assignments and to test the validity of the Cotton-Kraihanzel force field against a more complete one. For these particular complexes the simplified treatment appears sati~factory.~~ A similar but more extensive study using ,CO-enriched molecules has shown in addition that the rates of radial and equatorial exchange of CO groups with ,CO are approximately equal in disagreement with a previous inter-'* B.F. G. Johnson R. D. Johnston and J. Lewis Chem. Comm. 1967 1057. 39 H. Haas and R. K. Sheline J . Inorg. Nuclear Chem. 1967,29,693; E. A. C. Lucken K. Noack, 40 C. H. Wei G. R. Wilkes and L. F. Dahl J . Amer. Chem. Soc. 1967,89,4792. 41 P. Chini Chem Comm. 1967 29; P. Chini ibid. p. 440. 42 S. H. H. Chaston and F. G. A. Stone Chem. Comm 1967,964. 43 S. F. A. Kettle J . Chem. SOC. (A) 1967 314. 44 L. Malatesta and G. Caglio Chem Comm. 1967 420. 45 V. Albano P. Bellon and V. Scatturin Chem. Comm. 1967 730. 4' F. A. Cotton A. Musco and G. Yagupsky Znorg. Chem. 1967,6 1357. and D. F. Williams J . Chem. SOC. (A) 1967 148. I. J. Hyams D. Jones and E. R. Lippincott J .Chem Soc. (A) 1967 1987 Transition-M eta1 Carbonyls and Organometallic Complexes 323 pretation of radiocarbon tracer studies.48 A new treatment has been developed, based on the Cotton-Kraihanzel force field for calculating approximate force constants in molecules where two different sets of CO ligands are pre~ent.~’ The far-i.r. spectra of Mn(CO),X (X = C1 Br or I) have been recorded,” and the mass spectra for these and related carbonyl halides.’ ’ The carbonyl bands in the i.r. spectrum of OS(CO)~B~~ and Os(CO),I have been a~signed’~ and solvent effects on specific vibrational modes discussed.’ There has been increased interest in the relative intensities of CO absorp-tions in metal complexes; the integrated intensities of the CO stretching modes have been determined for a series of halogenocarbonyl derivative^'^ and for decarbonyldimanganese and its isoelectronic analogues.Two differ-ent approaches for calculating bond angles from. the data have been described but approximations inherent in both place a severe limitation on the accuracy of these calculations.56* ’’ The preparation of many new carbonyl halides has been reported; a variety of previously tried synthetic methods have been used successfully but the most fruitful have been (i) the action of neutral ligands on known carbonyl halides, (ii) halogen oxidation of carbonyls and their derivatives and (iii) direct sub-stitution of carbonyl groups by halide ions. Examples of each of these now follow. Reaction of Cr(CO),I with liquid ammonia gives [Cr(C0)2(NH3),]I.From the more complex reaction of Cr2(CO), with liquid ammonia an anionic species [Cr(C0)3(NH3)21]- is identified as one of the product^.'^ Carbonyl halide complexes of molybdenum and tungsten presumably seven-co-ordinate, can be readily synthesised by methods (i) or (ii). The action of L on M(C0)4X2 [M = Mo L = pyridine (py) 2,2’-bipyridyl (bipy) or 1,lO-phenanthroline (phen); M = W L = PPh, AsPh, or SbPh3 ; X = C1 or Br] gives complexes of formula M(C0)3L2X2.59 Iodine oxidation of M(C0)2L2 (M = Mo or W; L = bipy or phen] and of M(CO),(PPh,) [M = M o or W] give respectively cationic and anionic carbonyl halide derivatives e.g. [Mo(CO)~ bipy21]+ and [W(CO),(PPh,)I,] -.60 “ Halogen oxidation of the related (x-C,H,)Mo(CO),X leads to yet another type of product, 48 H.D. Kaesz R. Bau D. Hendrickson and J. M. Smith J . Amer. Chem. SOC. 1967 89 2844; B. F. G. Johnson J. Lewis J. R. Miller B. J. Robinson P. W. Robinson and A. Wojcicki Chem. Comm. 1967,379. 4y G. Bor Znorg. Chim. Act% 1967 1 81. V. Valenti F. Cariati C. Forese and G. Zerbi Znorg. Nuclear Chem Letters 1967,3 237. K. Edgar B. F. G. Johnson J. Lewis I. G. Williams and J. M. Wilson J . Chem SOC. (A), 1967,379. 5 2 L. A. W. Hales and R. J. Irving J . Chem SOC. (A) 1967 1389. 53 L. A. W. Hales and R. J. Irving Spechochim. Acta 1967 234 2981. 54 E. W. Abel and I. S. Butler Trans. Faraday SOC. 1967,63,45. ” R. M. Wing and D. C. Crocker Znorg. Chem. 1967,6,289. ’‘ T . L. Brown and D. J. Darensbourg Znorg. Chem. 1967,6 975. ’’ P. S. Braterman R. Bau and H. D.Kaesz Znorg. Chem. 1967,6 2101. ’’ H. Behrens and D. Herrmann Z . anorg. Chem. 1967,351,225. ” M. W. Anker R. Colton and I. B. Tomkins Austral. J . Chem. 1967 20 9; R. Colton and 6o H. Behrens and J. Rosenfelder Z . anorg. Chem. 1967,352,61. 61 J. Lewis and R. Whyman J. Chem SOC. (A) 1967,77. I. B. Tomkins ibid. 13 324 J . A. McGinnety and M . J . Mays (~-CsHs)Mo(CO)2X3.62 Iodine oxidation of Hg[Co(C0),I2 enables Co(CO),I to be prepared.63 The action of iodine on Fe,(CO), gives the interesting com-plex Fe2(C0)81 as air-sensitive white crystals which melt at - 5” to a red liquid; dissociation of this complex to Fe(CO),I is virtually complete in the gas-phase at room temperature and the red colour of the liquid is attributed to minute amounts of the monomer in the liquid phase.64 The reaction of tetra-alkyl-ammonium halides with metal carbonyls has been extended to Fe3(C0)12, giving the ion [Fe(CO),I] - ;65 some pseudohalides are also effective as reagents and e.g.KC(CN)3 reacts with M(CO) (M = Cr Mo or W) to give K[ M(CO),C(CN),] 66 while KCN reacts with Mn(CO) C1 giving K3Mn(C0)3(CN),.67 Carbonyl halide complexes of the platinum metals are often obtainable by direct carbonylation of metal halides. These carbonylation reactions are often rather unexpected For example a number of new anionic carbonyl halides of osmium ruthenium and iridium have been synthesised by heating the metal halides or halogeno- complexes under reflux with formic acid:68 in the case of ruthenium halides if hydrohalogenic acid is added to the reaction mixture the dicarbonyldihalides [ RU(CO)~X,] can be isolated in quantitative yield.69 Direct carbonylation of ruthenium trichloride takes place in methanol at low carbon monoxide pressures; a mixture of two isomers of [Ru(CO),Cl2], is obtained.34 The direct carbonylation of aqueous acidic rhodium trichloride has also been studied (80” 1 atm.) and is an autocatalytic reaction.[Rh(CO),Cl,]- is formed in solution and the kinetics of the reaction are consistent with a mechanism in which CO insertion is the initial rate-determining step:70 RhlI1 H,O + CO% Rhlll-.CO,H + H+ ‘““t-Rh’ + CO + 2H+ Details of the preparation of thiocarbonyl complexes of rhodium have been given.71 Contrary to an earlier report,72 the action of C,F on PtHCl(PEt,), does not give PtHCl(PEt3)2(C2F,).Instead X-ray evidence shows that a carbonyl-containing cationic species [PtCl(CO)(PEt,),] + is formed.73 This reaction has been extended to rhodium complexes and it seems that the oxygen must come from the glass tube in which the reaction is conducted or 62 M. L. H. Green and W. E. Lindsell J . Chem. Soc. (A) 1967 686. 63 M. Pankowski and M. Bigorgne Compt. rend. 1967 264 1382. 64 F. A. Cotton and B. F. G. Johnson Znorg. Chem. 1967,11,2113. 6 5 E. W. Abel 1. S. Butler and C. R. Jenkins J . Organometallic Chem. 1967,8 382. 66 W. Beck R. E. Nitzschmann and H. S. Smedal J . Organometallic Chem. 1967,8 547. 67 H. Behrens E. Ruyter and E. Lindner 2. anorg. Chem. 1967. 349,251. M. J. Cleare and W. P. Grifith Chem and Znd. 1967 1705. 69 R. Colton and R.H. Farthing J . Austral. Chem. 1967 #) 1283. 70 B. R. James and G . I. Rempcl. Chrm. Comm. 1967 158. 7 1 M. C. Baird G. Hartwell jun and G. Wilkinson J . Chem. SOC. (A) 1967 2037. 7 2 H. C. Clark and W. S. Tsang J . Amer. Chem. SOC. 1967,89 529. 73 H. C. Clark P. W. R. Corlield K. R. Dixon and 3. A. Ibers J . Amer. Chem. Soc. 1967,89,3360 Transition-M eta1 Carbonyls and Organometallic Complexes 325 from the presence of moisture.74 A convenient route to the versatile complexes, IrX(CO)L (X = halogen; L = t-phosphine] has been described” and MX(CO)L2 complexes [M = Rh Pd or Pt; L = Ph,P] have been syn-t h e s i ~ e d . ~ ~ Hydrides.-(a) Structure. Two theoretical treatments of bond-lengths in transition-metal hydrides have appeared. One is based on calculations of overlap integrals7’ and the other relies on the ‘united atom’ approach.78 This second treatment predicts an Mn-H distance of ca.1.60 A in HMn(CO) and a Co-H distance of ca. 1.4 A in HCo(CO)& Values of 1.28 and 1.42 A had been calculated for these distances on the basis of a broad-line n.m.r. study,” but a reinterpretation of the data gives values of 1.44 0.03 and 1.59 & 0.04 ASo which are in good agreement with the theoretical treatment con-sidering the simplicity of the model. Raman“ and i.r. spectraa2 of carbonyl metal hydrides have been further studied. Complexes containing a M-H-M bridge can be divided into two classes; those in which the hydrogen bridge is the only link between two metal atoms and those in which there are additional bridging groups.Examples of both types of complex have appeared during the year. An X-ray study of (C0)4Mn(H)PPh2Mn(CO)4 reveals a distorted octahedral co-ordination round each manganese atom consisting of four carbonyl groups and the bridging hydrogen and phosphorus atoms. Although the average position of the bridging hydrogen atom was found it is not possible from diffraction data to distinguish between the symmetric placement of the hydrogen atom in a single-minimum potential well between the metal atoms or in a symmetric double-minimum potential well.83 The crystal structure of HRe,(Mn(CO),, involves an L-shaped configuration of metal atoms in which it has been suggested that the hydrogen atom is located between the two rhenium atoms Mn I i.e. Re-H-Re; the evidence for this is the long Re-Re bond length of 3*39A compared with 3.02 A in Re2(C0),o.84 There is a double hydrogen bridge between copper and boron in the complex (P~,P),CU(BH,)~~ and 74 R.D. W. Kemmit and D. I. Nichols Chem. Comm. 1967,919. 7s J. Chatt N. P. Johnson and B. L. Shaw J . Chem. SOC. (A) 1967,604. 76 R. D. W. Kemmit D. I. Nichols and R. D. Peacock Chem. Comm. 1967 599. ?7 D. A. Brown and N. J. Fitzpatrick J . Chem. SOC. (A) 1967 1793. 78 W. G. McDugle and T. C. Brown J . Amer. Chem. SOC. 1967,89 3111. 79 T. C. Farrer S. W. Ryan A. Davison and J. W. Faller J . A m . Chem. SOC. 1966 88 184; T. C. Farrer F. E. Brinckmann T. D. Coyle and J. W. Faller Inorg. Chem. 1967 6 161. G. M. Sheldrick Chem. Comm. 1967,751. A. Davison and J. W. Faller Znorg. Chem.1967,6 845. 82 G. Bor Znorg. Chim Acta 1967 1 81; P. S. Braterman R. W. Harrill and H. D. Kaesz, 83 R. J. Doedens W. T. Robinson and J. A. Ibers J . Amer. Chem. SOC. 1967,89,4323. 84 M. R. Churchill and R. Bau Znorg. Chem. 1967,6 2086. J . Amer. Chem. SOC. 1967,89,2851. S. J. Lippard and K. M. Malmer J . Amer. Chem SOC. 1967,89 3929 326 probably also in (Ph3P)2Cu(B3H8).86 In Zr(BH,) the zirconium atom is surrounded tetrahedrally by the four boron atoms and there are three hydrogen bridges from zirconium to each boron i.e. twelve bridging hydrogen atoms in all.’’ The complex (n-C5H5),Rh3H contains an equilateral triangle of rhodium atoms and it seems likely that the hydrogen atom is in or near the Rh3 plane and bridges all three atoms.” In HFeCo,(CO), it has been suggested on the basis of mass spectroscopic and i.r.evidence that the hydrogen atom may be located inside the metal-atom tetrahedron and bridge four atoms.89 It may well be that all polynuclear carbonyl hydrides will prove to have their hydrogen atoms located in bridging positions. Weak interactions between a metal atom and a hydrogen atom attached to a ligand have been suggested in a number of cases e.g. between the o-hydrogen of a phenyl ring and the iridium atom in [Ir(CO)(diphos),]Cl (diphos = Ph2P*CH2 *CH PPh,)” and between sulphur-bonded hydrogen and platinum in one isomeric form of (Ph,P),Pt,H,S.’l In some cases hydrogen can be transferred completely from a ligand atom to the metal and an example of this is the formation of a direct metal-hydrogen bond when the new complex Ir(PPh,),Cl is heated in a suitable solvent; deuteriation shows that the hydrogen is extracted from the co-ordinated ph~sphine.’~ (b) New complexes and reactions.[(n-C,H,)ZrH,] and (n-C,H,)TcH are new hydrides of relatively unstudied elements to be prepared during the year.’ Metal hydride complexes are often formed in unexpected ways; for example refluxing decarbonyl dimanganese with Ph,P or (PhO)3P in xylene yields the species HMn(C0)3L,.94 Reduction of MeMn(CO)S with sodium borohydride followed by acidification gives H,Mn,(CO), in high yield, instead of the expected carbene complex ;” another convenient synthesis for this hydride has been de~cribed.’~ New polynuclear carbonyl hydrides pre-pared include the anionic species [HIrJCO) Until this year all well characterised transition-metal hydride complexes have been diamagnetic, but a red crystalline paramagnetic hydride [OsHCl,(PBu~Ph),] has now been isolated.An isomer is obtained by boiling this complex in carbon tetra-chloride; air and moisture are involved in the isomerisation process.” An J . A. McGinnety and M . J . Mays s6 S. J. Lippard and D. Ucko Chem Comm. 1967 983. ’’ P. H. Bird and M. R. Churchill Chem. Comm. 1967,403. ss E. 0. Fischer 0. S. Mills E. F. Paulus and H. Wawersik Chem. Comm. 1967 643. ’’ M. J. Mays and R. N. F. Simpson Chem. Comm. 1967 1024. ’O J. A. J. Jarvis R. H. B. Mais P. G. Owston and K. A. Taylor Chem. Comm. 1966,906. 91 D. Morelli A. Segre R. Ugo G. La Monica S. Cenini F. Conti and F. Bonati Chem. Comm., 92 M.A. Bennett and D. L. Milner Chem. Comm. 1967 581. ” B. D. James R. K. Nanda and M. G. H. Wallbridge Znorg. Chem. 1967,6,1979; E. 0. Fischer 94 R. Ugo and F. Bonati J . Organometallic Chem. 1967,8 189. ” E. 0. Fischer and R. Aumann J . Organometallic Chem. 1967,8 P1. 96 B. F. G. Johnson R. D. Johnston J. Lewis and B. H. Robinson J . Organometallic Chem., ’’ J. Chatt G. J. Leigh and R. J. Paske Chem. Comm. 1967 671. 1967,524. and M. W. Schmidt Angew Chem Znternat. Edn. 1967,693. 1967 10. 105 Transition-M eta1 Carbonyls and Organometallic Complexes 327 osmium carbonyl hydride H,Os(CO), is obtained from the reaction of osmium tetroxide carbon monoxide and hydrogen at high temperatures and pressures. It is the first example of a monomeric carbonyl hydride which can be obtained by the direct reaction of a monomeric carbonyl with hydr~gen.~' Aqueous solutions of potassium pentacyanocobaltate catalyse the homo-geneous hydrogenation of conjugated olefins.The kinetics of hydrogen uptake by this catalyst has been further studied" and evidence that the active species is [CoH(CN),I3- has been provided by isolation of this complex as a mixture of its sodium and caesium salts.'" The corresponding iridium complex, K3[IrH(CN)5] has also been prepared from the reaction of Ir(C6H8),Cl with an excess of methanolic potassium cyanide although previously only K,[RhH(CN),(H,O)] had been isolated from the reaction with Rh,(CO),Cl,.' O1 The potential importance of platinum metal complexes as homogeneous catalysts has stimulated research in this area generally.The reactions and catalytic properties of rhodium complexes in solution have been reviewed. ' O2 The ruthenium complex RuHCI(PPh,) is a selective catalyst for the hydro-genation of terminal olefins. Experiments on olefin isomerisation and hydrogen-atom exchange using this catalyst clearly show the direct involve-ment of metal-hydrogen bonds in these processes which must proceed uia the reversible formation of an alkyl intermediate. The reversible formation of an Ru-Et bond with ethylene under pressure can indeed be demon-strated. lo3 Further kinetic studies on the homogeneous hydrogenation of olefins using RhX(PPh,) [X = C1 Br or I] as catalysts have been madelo4 and the poisoning effects of sulphur compounds on these catalysts investi-gated.lo' The reaction of hydrogen chloride with RhCI(PPh,)3 gives RhHCl,(PPh,) which is probably six-co-ordinate with a solvent-occupied site. This complex readily undergoes insertion reactions with C2H4 C2F4, and C2H2 to give RhCl,(R)(PPh,) [R = Et C2F,H or C2H3].lo6 Addition reactions of related molecules have been described. lo' Rhodium@) complexes containing R h 4 bonds have been obtained for the first time by the action of Grignard reagents on RhCl(PPh3)3 e.g. Rh(Me)(PPh,) has been prepared. RhH(PPh3)3 is formed in high yield on treating RhCl(PPh3)3 with a stoicheio-metric amount of aluminium tri-isopropyl probably by elimination of propylene from Rh[CHMe2](PPh3)3.108 Iridium hydride complexes are effective catalysts for many organic reactions. For example the new hydride, 98 F.L. L'Eplattenier and F. Calderazzo Znorg. Chem. 1967 6 2092. 99 M. G. Burnett P. J. Connolly and C. Kemball J . Chem SOC. (A) 1967 800. K. Krogmann and W. Binder Angew. Chem Znternat. Edn. 1967,6,881. P. S. Hallman D. Evans J. k Osborn and G. Wilkinson Chem. Comm. 1967 305. F. H. Jardine J. A. Osborn and G. Wilkinson J . Chem SOC. (A) 1967 1574. M. C. Baud J.T. Mague J. A. Osborn and G. Wilkinson J . Chem SOC. (A) 1967 1347. loo R. G. S. Banks and J. M. Pratt Chem Comm. 1967,776. lo' B. R. James Co-ord. Chem Rev. 1967,1,505. lo5 A. J. Birch and K. A. M. Walker Tetrahedron Letters 1967 1935. "' J. Chatt and S. A. Butter. Chem. Comm 1967,501. '"' W. Keim J . Urganometollic Chem. 1967,s. P25. L 328 J . A. McGinnety and M . J. Mays IrHCl2(Me,SO), catalyses the transfer of hydrogen from propan-2-01 to ap-unsaturated ketones'0g and IrH,(PPh,) catalyses both the homogeneous hydrogenation of aldehydes and the homogeneous decomposition of formic acid.' When PdC12(PPh3)2 is reduced with Me,GeH Pd(H)Cl(PPh,) is obtained; this is quite stable in the absence of oxygen but only in neutral media which accounts for previous failures to prepare palladium hydride complexes since these generally involve reduction in strongly basic or acidic media.' ' ' The chemistry of platinum hydride complexes has been reviewed.' ' Some platinum-phosphine complexes are active hydrogenation catalysts particu-larly in the presence of stannous chloride. In some cases hydride intermediates can be isolated in which platinum is simultaneously bonded to hydrogen tin, and olefin e.g.Pt(H)(SnC1,)(C8Hl6)(PPh3),.' ' Molecular Nitrogen Adducts.-It has been conclusively demonstrated that molecular nitrogen can react with suitable substrates at room temperature and pressure to form stable adducts. Pure gaseous nitrogen reacts with a solution of a tris(tripheny1phosphine)cobalt species to form a 1 1 adduct which can be isolated as an orange crystalline solid. The exact formula of the isolated solid has not been established beyond doubt and it may be a mixture of the two compounds CoH(N,)(Ph,P) and Co(N,)(Ph,P),. The reactive cobalt species can be prepared by reduction of tris(acqtylacetonato)cobalt(irr) using ethoxydiethylaluminium' l4 or tri-isobutylaluminium' '' in the presence of triphenylphosphine.There have been three reports of the preparation of tris(tripheny1phosphine)cobalt hydrides which react with molecular nitrogen to form a 1 1 adduct with displacement of two hydrogen atoms. This reaction is reversible and the hydride can be prepared by passing gaseous hydrogen through a solution of the nitrogen adduct.' l 6 One hydride CoH,L, is formed by reduction of CoX,L (X = C1 Br or I; L = Ph,P or Ph,EtP) using a borohydride in the presence of excess L,"' and gives a nitrogen adduct CoH(N2)L3. In another report,"* a hydride CoH2(Ph3P) was prepared by reduction of tris(acetylacetonato)cobalt(rrI) with tri-isobutylaluminium in the presence of triphenylphosphine and gaseous hydrogen ; this gives a nitrogen adduct Co(N,)(Ph,P),. The first compounds reported to contain molecular nitrogen, [Ru(NH~)~N,~+][X-]~ are prepared by the action of hydrazine hydrate '09 J.Trocha-Grimshaw and H. B. Henbest Chem. Comm. 1967 544. R. S. Coffey Chem Comm. 1967,923. E. H. Brooks and F. Glockling J . Chem SOC. (A) 1967 1030. 'I2 R. J. Cross Organometallic Chem Rev. 1967 2 97. 113 H. A. Tayim and J. C. Bailar J . Amer. Chem. SOC. 1967,89,3420; H. A. Tayim and J. C. Bailar, ibid. 4330. A. Yamamoto S. Kitazume L. S. Pu and S. Ikeda Chem. Comm. 1967,79. A. Yamamoto L. S. Pu S. Kitazume and S. Ikeda J . Amer. Chem SOC. 1967,89 3071. A. Misono Y. Uchida and T. Saito &ll. Chem. SOC. Japan 1967,40 700. A. Misono Y. Uchida T. Saito and K. M. Song Chem. Comm. 1967,419. 'I7 A. Sacco and M. Rossi Chem Comm. 1967. 316 Transition-M eta1 Carbonyls and Organometallic Complexes 329 upon salts of tri- or tetra-valent ruthenium and full details of the preparation and properties of these compounds have been reported.' '' The corresponding osmium compounds have been prepared by an analogous reaction.'20* 12' The ruthenium cation can also be prepared by the direct reaction of molecular nitrogen' 22 with solutions of salts of [Ru(NH3),,H2O2 '1.Chlorocarbonyl-bistriphenylphosphineiridium(1) reacts with acyl azides to form IrCl(N,) (Ph,P) ; the mechanism of this reaction has been examined.'23 The analogous molecular nitrogen complex of rhodium is formed by a similar reaction.' 24 Formation of a molecular nitrogen adduct may be one step in the fixation of nitrogen by biological systems and these isolable nitrogen adducts may yield information about the conditions for fixation of molecular nitrogen.Another chemical reaction with potential analogies in the biological fixation of nitrogen is the reduction of the adduct of a diazonium salt with hydrido-chlorobistriethylphosphineplatinum(r1) ; the reduction proceeds in two Gages and hydridochlorobistriethylphosphineplatinum(1~) is reformed. ' ' Studies have also been. made of systems in which molecular nitrogen is converted to ammonia at room temperature and pressure. 126-'28 In the nitrogen adducts thus far examined the N ligand is colinear with the central metal ion. However there is one report'29 of a nitrogen adduct with an unusual i.r. absorption spectrum and this compound may have a different stereochemistry.Nitrosy1s.-A well-resolved nitrogen hyperfine splitting due to the I4NH3 ligands is observed in the electron spin resonance spectrum of [Cr(NH,) NO] +.' 30 The e.s.r. spectra of [Cr(CN),NO13 - and [Mo(CN),N0I3- have also been recorded; that of the former provides some evidence for a non-linearity of the Cr,-N-O gro~ps.'~' The reduction of [Cr(CN),N0I3 - to [Cr(CN),N0I4- has been studied polarographically.'32 Strong electron-donors react with (I~-C,H,)C~(NO),CI replacing one nitrosyl group to give (7c-C,H5)Cr(NO)LC1 complexes (L = e.g. py Ph,P or C6HllNC) which have a magnetic moment corresponding to one unpaired A. D. Allen F. Bottomley R. 0. Harris V. P. Reinsalu and C. V. Senoff J . Amer. Chem. A. D. Allen and J. R. Stevens Chem. Comm. 1967 1147.Yu. G. Borod'ko V. S. Burkeev G. I. Kozub M. L. Khidekel and A. E. Shilov Zhur. stnrkt. SOC. 1967,89,5595. Khim. 1967,8 542. 12' D. E. Harrison and H. Taube J . Amer. Chem SOC. 1967,89 5706. lZ4 L. Yu. Ukhin Yu. A. Shvetsov and M. L. Khidekel' Zzvest. Akad. Nauk. S.S.S.R. Ser. khim., lZ5 G. W. Parshall J . Amer. Chem. SOC. 1967,89 1822. lZ6 E. E. van Tamelen G. Boche S. W. Ela and R. B. Fechter J . Amer. Chem. SOC. 1967,89,5707. R. Maskill and J. M. Pratt Chem. Comm. 1967,950. "* G. Henrici-Oh6 and S. Oliv6 Angew. Chem Internat. Edn. 1967 6 873. J. L. Johnson and W. D. Beveridge Znorg. NucZear Chem. Letters 1967 3,323. lJo P. T. Manoharan H. A. Kuska and M. T. Rogers J . Amer. Chem. SOC. 1967,89,4564. B. R. McGarvey and J. Pearlman J . Chem. Phys. 1967,46,4992-; R G.Hayes J . Chem Phys., J. P. Collman M. Kubota J. Sun and F. Vastine J . Amer. Chem. SOC. 1967,89 169. 1967,957. 1967,47,1692. "' D. 1. Bustin and A. A. Wek Coil. Czech. Comm. 1967,32 1665 330 J . A. McGinnety and M. J. Mays electron.'33 Treatment of (7c-C,H,)MoNO(CO) with iodine gives dimeric [(~-C,H,)MO(NO)I,]~ which probably contains a double iodine bridge ; treatment of this with phosphine ligands (L) gives (n-C,H,)Mo(NO)I,L. Two geometric isomers are possible for these latter complexes and where L = (PhO),P both isomers can be identified in solution from n.m.r. spectra.134 The reaction of (CF,),C2S2 with (n-C,H,)Mo(NO)(CO) and related com-plexes has also been investigated." A convenient synthesis of Mn(NO)(C0)4 and of Mn(NO),(CO) has been described'36 and the rates and mechanisms of some substitution reactions of these molecules have been studied while the former reacts by a second-order process replacement of CO from the latter is largely a first-order r e a ~ t i 0 n .I ~ ~ The crystal structures of the five-co-ordinate nitrosyl complex Mn(NO)(CO),[PPh,], and of the six-co-ordinate K,Mn(CN),(NO) have been reported ; the Mn-N bond lengths (ca. 1.7 A) are similar in the two compounds.138* A s eries of r~theniurn'~' and osmium141 complexes of formula RuX,(NO)L (X = halogen; L = PR3 or AsR,) have been prepared; dipole moments suggest that the phosphine or arsine ligands are trans to each other. The reaction of nitric oxide with cobalt(I1) ammine complexes has been further studied and a mechanism to explain the formation of [am,C~(N,O,)~-Coam,]~+ (am = ammine) has been proposed, based on the general reaction of NO with reducing agents.A cis or skew configuration for the (N,O,)'- ligand is indi~ated.'~ The reaction of nitric oxide with the p-crystalline forms of some metal phthalocyanines of the first transition-metal series have been reported; Cr Mn Fe and Co phthalocyanines form mononitrosyl derivative^.'^^ The mass spectra of a number of nitrosyl complexes have been in~estigated.'~~ Nitrile and Isonitrile Complexes.-Some reactions of the carbonyl cyanide anions [M(CO),CN]- (M = Cr Mo or W) have been studied; on treatment with Me,SnCl the trimethyltin isocyanide complexes Me,SnNCM(CO), are obtained while in 4~-aqueous hydrochloric acid the anions are protonated to give volatile hydrogen isocyanide complexes of formula HNCM(CO),.145 The Mossbauer spectra of a series of cyanide and isocyanide complexes of iron have been studied.'46 13' E. 0. Fischer and H. Strametz J . Organometallic Chem. 1967,10,323. 134 R. B. King Znorg. Chem. 1967,6,30. lJ5 R. B. King and M. B. Bisnette Znorg. Chem. 1967,6,469. H. Wawersik and F. Basolo Znorg. Chem. 1967 6 1066. l'' H. Wawersik and F. Basolo J . Amer. Chem SOC. 1967,89,4626. 13* J. H. Enemark and J. A. Ibers Znorg. Chem. 1967,6,1575. 139 A. Tullberg and N. G. Vannerberg Acta Chem Scad. 1967,21,1462. 140 J. Chatt and B. L. Shaw J . Chem. SOC. (A) 1966,1811. '*' A. Araneo and C. Bianchi Gazzetta 1967,W 885. '*' P. Gans J . Chem. SOC. (A) 1967,943. 14' C. Ercolani and C. Neri J.Chem SOC. (A) 1967 1715. B. F. G. Johnson J. Lewis G. Williams and J. M. Wilson J . Chem. SOC. (A) 1967 338; A. Foffani S. Pignataro G. Distefano. and G . Innorta J . Organometallic Chem. 1967 7 473. 14' R. B. King Inorg. Chem 1967,6,25. 146 R. R. Berrett and B. W. Fitzsimmons J . Chem. SOC. ( A ) 1967 525 Transition- M eta1 Carbonyls and Organometallic Comptexes 33 1 The complex [L,COCOL,](C~O~)~ (L = MeNC) is a red diamagnetic solid which X-ray analysis has shown to be a six-co-ordinate dimer with a metal-metal bond. The corresponding phenyl isocyanide complex a blue para-magnetic monomer was previously assumed to be the five-co-ordinate [(PhNC)SCo]2 + ; it is however the sixco-ordinate hydrate [(PhNC)SCo(H20)]2+ and can be dehydrated to a yellow complex which is indeed five-co-ordinate and probably square-pyramidal.Both the phenyl and methyl isocyanide complexes are present as the six-co-ordinate hydrates in solution although at high ligand-concentrations a violet species thought to be the complex [(CH3NC)&oI2+ is f~rmed.'~' Treatment of Ni(l,5-C8H12)2 with Bu'NC gives the complex Ni(Bu'NC) which takes up one mole of oxygen at - 20" forming Ni(Bu'NC),O ; excess Bu'NC is catalytically oxidised to Bu'NCO by air at room femperat~re.'~~ The nitrile group can co-ordinate to a metal either through the lone pair on the nitrogen atom or through the It-electrons of the C-N triple bond. Some new rhenium complexes ReX3(MeCN)(PPh3)2 (X = halogen) are probably of the first type,'49 while an X-ray structure analysis of the complex [(C5HloNCN)Ni(CO)] shows that it is a tetramer in which each nickel atom is co-ordinated by a It-bonded CiN group from one ligand the lone pair on the nitrogen atom of a second ligand and by a carbonyl group(r).'" \ \ Ni, ,N'C,f N Ni-1 I N / c /c 'N 0 I A ruthenium@) complex (CH2 CHCN),RuCl, is formed when RuCl,, 3H20 is refluxed with acrylonitrile in ethanol.1.r. evidence indicates that the ligand is bonded through the terminal nitrogen atom.' 51 The photochemical preparation of monosubstituted carbonyl complexes containing acrylonitrile has been reported. Whether the ligand acts as a donor through the nitrogen atom or whether a It-olefin complex is formed has been related to the A-donating ability of the metal atom.lS2 The low-frequency i.r.spectra of acetonitrile and acrylonitrile derivatives of chromium molybdenum and tungsten hexacarbonyls have been recorded. 53 14' J. M. Pratt and P. R. Silverman Chem Comm. 1967 117; J. M. Pratt and P. R. Silverman, J . Chem. Soc. (A) 1967,1286. S. Otsuka A. Nakamura and Y. Tatsuno Chem Comm. 1967 836. 149 G. Rouschias and G. Wilkinson J . Chem SOC. (A) 1967,993. "O K. KrogmaM and R. Mattes Angew. Chem Internat. Edn. 1966,5 1046. lS1 J. Guttmberger and W. Strohmeier h. 1967,100,2807. A. Misono Y. Uchida M. Hidai and H. Kania Chem Comm 1967,357. M. F. Farona J. G. Graselli and B. L. Ross Spectrochim. Acta 1967 23A. 1875 332 J . A. McGinnety and M . J . Mays Molecular Oxygen Addncts.-The stereochemistry of molecular oxygen as a ligand depends upon the stoicheiometry of the adduct.In the 2 1 adducts formed by some cobalt compounds the O2 group bridges the two cobalt atoms; the exact shape of the bridge varies from one cobalt compound to another.' 54 Iridium complexes of general formula IrX(CO)(Ph,P) (X = C1, Br or I) react with molecular oxygen to form 1 1 adducts. The structure of the iodo-adduct has been determined and the two oxygen atoms are equi-distant from iridium. As the halogen is varied in the parent iridium complexes, there are changes in the reactivity towards molecular oxygen and the bonding in the adducts can'be described by a model similar to the x-bonding model used for ethylene adducts of transition-metal complexes.'55* ' 56 The 1 7 0 n.m.r. spectrum of 70-enriched oxyhaemoglobin is a single line which over-laps with the H2170 re~onance.'~' This is not consistent with asymmetric binding of the oxygen molecule and suggests there are analogies with the iridium systems.Molecular oxygen reacts in solution with M(Ph,P) (M = Ni Pd or Pt), to form the adducts M(02)(Ph3P)2.'58* lS9 The oxygenated platinum complex oxidises sulphur dioxide carbon dioxide and dinitrogen tetroxide to form platinum complexes that contain the oxidised moiety;160-162 the structure of the carbonato-complex Pt(C03)(Ph,P) has been determined16 and the co-ordination around platinum is distorted square-planar. The similarities between molecular oxygen and ethylene are exemplified by the conversion of Pt(O2)(Ph,P) to the isoelectronic ethylene adduct. ' 59 The kinetics of the reversible reaction of molecular oxygen with bishistidin-atocobalt(r1) are consistent with a two-step mechanism.164 The first step involves formation of the 1 1 adduct dioxygenbishistidinatocobalt which reacts with another molecule of bishistidinatocobalt(I1) to form the known product pdioxygen-tetrakishistidinatodicobalt(I1). This reversibly oxygenated product reacts slowly and irreversibly with a second molecule of oxygen to form cobalt(rr1) species. This irreversible reaction is thought to proceed by loss of co-ordinated histidine from the binuclear reagent followed by reaction with molecular oxygen to form dioxygenhistidinatocablt which decomposes to cobalt(m) species. '" The preparation and interconversion of some binuclear lS4 U. Thewalt and R. Marsh J .A m . Chem SOC. 1967,89,6364. lS5 J. A. McGinnety R. J. Doedens and J. A. Ibers Science 1967,155,709. 156 J. A. McGinnety R. J. Doedens and J. A. Ibers Inorg. Chem. 1967 6,2243. 15' S. MariEiC J. S. Leigh jun. and D. E. Sunko Nature 1967,214,462. 15* G. Wilke H. Schott and P. Heinbach Angew. Chem Internat. Edn. 1967,6,92. 159 C. D. Cook and G. S. Jauhal Inorg. Nuclear Chem Letters 1967,3,31. C. D. Cook and G. S. Jauhal J . Amer. Chem. SOC. 1967,89,3066. 161 J. J. Levison and S. D. Robinson Chem Comm 1967 198. C. J. Nyman C. E. Wymore and G. Wilkinson Chem Comm. 1967,407. 163 F. Cariati R. Mason G. B. Robertson and R. Ugo Chem Comm. 1967,408. 16* J. Simplicio and R G. Wilkins J . Amer. Chem SOC. 1967,89,6092. 165 L. J. Zompa C. S. Sokol and C. H. Brubacker jun.Chem. Comm. 1967 701 Transition-M eta1 Carbonyls and Organometallic Complexes 333 peroxo-complexes of cobalt have been re-examined'66y and a binuclear peroxo-complex of ruthenium has been prepared.'68 Group IV Derivatives.-Derivatives containing transition metals bonded to silicon germanium tin and lead will be dealt with in this section; carbon compounds will be treated separately. This area is still sufficiently new for the main emphasis to be on synthetic work particularly in the case of silicon. Methods used to synthesise Si-M bonds include reaction of Ph,SiLi or Me,SiLi with a metal carbonyl halide (Zr Mo or W);169*170 reaction of [Me3Si12Hg with a metal halide (Pt);I7' reaction of silanes with metal carbonyls either alone (Mo Mn Re Fe Co ?Ji),172 or in the presence of a base (Pt);" and finally the addition of silanes to square-planar complexes (Rh).' 74 Perhaps the most interesting silicon-transition metal complex prepared this year is the least complicated namely H,SiMn(C0)5 since it may readily be compared with its carbon analogue which has been well studied.The complex does not react with hydrogen chloride in the gas-phase at room temperature neither can carbonyl insertion be brought about either by the application of high carbon monoxide 'pressures or by reaction with triphenylphosphine although a carbonyl group is replaced by this reagent.17' F,SiCo(CO), the analogue of F,CCo(CO), has also been synthesised.' 76 The Co-Si bond length in Cl,SiCo(CO) is 2.25 A which provides no evidence in favour of multiple bonding.' The most thoroughly studied Group IV derivatives are those containing tin and there have been a number of X-ray structure determinations this year.The metal-metal bond lengths are quite sensitive to the other sub-stituents on both metals; e.g. Mn-Sn is 2.63 in Ph3SnMn(C0)4PPh3,'78 2.67 in Me,SnMn(CO),,' 7 9 2.73 in (CO),Co(SnPh,)Mn(CO),:80 and 2.74 A in ClSn[Mn(CO)& ;Is1 while Fe-Sn is 2-49 in [(n-C5H,)Fe(C0)2]2Sn(ON0)2 and [(x-C5H5)Fe(C0)2]2SnC12,'82* 2.54 in Sn[Fe(C0),],,lE4 2-59 in 166' A. G. Sykes and R. D. Mast J . Chem SOC. (A) 1967 784. 16' M. Mori and J. A. Weil J . Amer. Chem SOC. 1967,89,3732. 168 N. A. Ezerskaya and T. N. Solovykh Zhur. neorg. Khim. 1966,11 2569. 169 D. J. Cardin S. A. Keppie B. M. Kingston and M. F. Lappert Chem. Comm.1967 1035. 170 M. C. Baud J . Inorg. Nuclear Chem. 1967 29 367. 17* W. Jetz and W. A. G. Graham J . Amer. Chem SOC. 1967 89 2773; A. P. Hagen and A. G. 173 J. Chatt C. Eaborn S. Ibekwe and P. N. Kapoor Chem Comm. 1967 869. 174 R. N. Haszeldine R. V. Parish and D. J. Parry J . Organometallic Chem. 1967 9 P.13. 17' B. J. Aylett and J. M. Campbell J . Inorg. Nuclear Chem. Letters 1967 3 137. 176 A. P. Hagen and A. G. MacDiarmid Znorg. Chem. 1967,6 1941. 177 W. T. Robinson and J. A. Ibers Znorg. Chem. 1967,6 1208. 179 R. F. Bryan Chem. Comm. 1967,355. F. Glockling and K. A. Hooton J . Chem SOC. (A) 1967 1066. MacDiarmid Inorg. Chem. 1967,6 686. R. F. Bryan J. Chem SOC. (A) 1967 172. B. P. Kir'yukov Yu. T. Struchkov K. N. Anisimov N. E. Kolobova 0. P. Osipova and J.H. Tsai J. T. Flynn and F. P. Boer Chem. Comm. 1967,702. M. Ya. Sakharov Chem. Comm. 1967,749. le2 B. P. Bir'yukov Yu. T. Struchkov K. N. Anisimov N. E. Kolobova and V. V. Skripkin, lE3 J. E. O'Connor and E. R. Corey Inorg. Chem. 1967,6,968. lE4 P. F. Lindley and P. Woodward J . Chem. SOC. (A) 1967 382. Chem. Comm. 1967,750 334 J . A. McGinnety and M . J . Mays [(lr-CSH,)Fe(CO),],[(lr-CsH~)Mo(CO)3]SnCl,185 and 2.64 and 2 75 A for the two non-equivalent tin atoms in Me4Sn3Fe4(C0)16.'86 All these distances are shorter than the sum of appropriate covalent radii but there is as yet insufficient data from which to draw any general conclusions. Among new compounds synthesised are some pentafluorophenyltin deriva-tives of manganese a complex containing the four metal-atom chain Mn-Sn-Sn-Mn,187 and the complex S ~ [ C O ( C O ) ~ ] ~ ~ ~ ~ which does not lose carbon monoxide with the formation of cobalt-cobalt bonds despite the ease with which this occurs in related complexes of carbon and silicon e.g., CH2 *CHSi[Co(CO),],.It is interesting then that in the complex [C,H,O,],S~CO~(CO)~ the two cobalt atoms are bridged by tin a carbonyl group and a cobalt-cobalt bond presumably the six-co-ordinate tin allows a closer approach of the two cobalt atoms.'89 The reaction of SnCl with M-Cl bonds to give M-SnCl complexes is well known but the mechanism has not been studied. The formation of the complex (n-C,H,)Fe(C0)2SnCI,I,MeOH from (n-C,H,)Fe(CO),I and SnCl, in methanol suggests co-ordination of SnCl to the metal atom followed by an intramoleeular migration of the iodo-group from the transition metal to tin:"' a similar insertion mechanism has been proposed for the formation of the M-SnX group from M-HgX and SnX (X = hal~gen].'~' The reaction of (n-CSH,)Ni(PPh,)Cl with SnCl in acetone affords (lr-CSHS)Ni(PPh3)SnCl3 but in dichloromethane using an excess of phos-phine the ionic derivative [(n-CSHS)Ni(PPh3),]SnCl,,CH,Cl is formed.192 A new method of preparing SnCI3 complexes is the photolytic reaction of carbonyls with Ph,AsSnCl ; complexes such as Ph,As[M(CO),SnCl,] are obtained (M = Cr Mo or W).lg3 Several transition-metal-germanium compounds have been prepared. They are usually completely analogous to the tin derivatives; e.g. [(n-C,H,)Fe(C0)2]GeCl which is isomorphous with [(x-C,HS)Fe(CO),]SnCl2.194 Group V Derivatives.-@) Nitrogen. A number of interesting complexes have been prepared from the reaction of azocompounds organic isocyanates, mines and azides with metal carbonyls. Details of the structure of the azo-benzene adduct [Fe(C0)3]2(PhN NPh) (see last year's Annual Reports) have been published ;Ig5 a related cobalt complex in which the azobenzene similarly J. E. O'Connor and E. R. Corey J . A m . Chem SOC. 1967,89 3931. R. M. Sweet C. J. Fritchie and R. A. Schunn Znorg. Chem. 1967,6,749. J. A. J. Thompson and W. A. G. Graham Znorg. Chem. 1967,6 1875. M. Bigorne and A. Quintin Compt. rend. 1967,264 C 2055. la9 D. J. Patmore and W. A. G. Graham Chem Comm. 1967 7; D. J. Patmore and W. A. G. 190 A. R. Manning Chem Comm. 1966,906.19' F. Bonati S. Cenini and R. Ugo J . Chem SOC. (A) 1967,932. 19' M. van der Akker and F. Jellinek J . Organometallic Chem. 1967 10 P.37; P. A. McArdle and A. R. Manning Chem Comm. 1967,417. 193 J. K. Ruff Znorg. Chem. 1967,6 1502. 194 M. A. Bush and P. Woodward J. Chem SOC. (A) 1967,1833. '95 P. E. Baikie and 0. S. Mills Inorg. Chim. Acta. 1967 1 55. Graham Znorg. Chem. 1967,6,1879 Transition-M etal Carbonyls and Organometallic Complexes 335 rearranges to give an o-semidine ligand has been prepared.'96 Reaction of phenylisocyanate with dodecacarbonyl tri-iron gives a complex (PhN),Fe,(CO) which has been shown by mass spectros~opy'~~ and two X-ray determination^'^^ to have the structure (2). A corresponding cobalt A* ,Ph Ph C. complex [(R-C,H,)CO]~(NBU'),CO can be synthesised from (Bu'N),S and (I~-C,H,)CO(CO)~'~~ and the structure of a closely related iron complex, di-~-(4,4'-dimethylbenzophenoniminato)bis(tricarbonyliron) has also been re-ported.200 Diaryldiazomethane (aryl = Ph or p-tolyl) forms two complexes with Fe3(C0)',.An orange complex C3,H2,Fe2N406 is related to (2) since the crystal structure determination shows that two MeC,H,C N- NH ligands bridge two Fe(CO)3 residues through their NH groups. The N-H bonds take the place of the linking CO group in (2).201 The other complex (aryl = phenyl) is as shown in (3). The terminal nitrogen atoms of the ligands are equidistant from the three iron atoms. Two Fe-Fe distances (ca. 2.45 A) are shorter than the third (3.08L).202 Organic azides also give a range of complexes; with methyl azide one of the products is Me2N4Fe(C0)3 thought to contain MeN:N*N:NMe which is not known as a free ligand.,03 Related complexes with azomethine analogues of 1,3-dienes have been Aniline and cyclohexylamine react under mild conditions with (norborn-adiene)M(CO) (M = Cr or Mo) with the formation of trisubstituted deriva-tives L3M(C0)3.The arene (Ar) derivative ArM(CO), is also obtained in low yields in the case of aniline.,' A pyrrolyl complex (n-C,H,)Fe(CO),o-C4H4N) containing a metal-nitrogen o-bond has been prepared ; it readily rearranges to a n-pyrrolyl complex.207 Hexamethylborazoletricarbonyl-205 19' T. Joh N. Hagihara and S. Murahashi h l l . Chem SOC. Japan 1967,40,661. 19' W. T. Flannigan G. R. Knox and P. L. Pauson Chem.and Id. 1967 1094. 19* J. A. J. Jarvis B. E. Job B. T. Kilbourn R. H. B. Mais. P. G. Owston. and P. F. Todd. Chem. Comm. 1967 1149; J. Meunier-Piret P. Piret and M. van Meersche Bull. Soc. chim. helges 1967. 76,505. 199 Y. Matsu-Ura N. Yasuoka T. Ueki N. Kasai M. Kakudo T. Yoshida and S. Otsuka, Chem. Comm. 1967,1122. 2oo D. Bright and 0. S. Mills Chem Comm. 1967,245. *01 M. M. Bagya P. E. Baikie 0. S. Mills and P. L. Pauson Chem. Comm. 1967 1106. '02 P. E. Baikie and 0. S. Mills Chem Comm. 1967 1228. 203 M. Dekker and G. R. Knox Chem Comm. 1967,1243. 204 S. Otsuka T. Yoshida and A. Nakamura Znorg. Chem. 1967,6 20. 2os H. Bock and H. tom Dieck Chem Ber. 1967,100,228. 206 H. Werner and R. PrinZ Chem Bm. 1967,100,265. 'O' P. L. Pauson and A. R. Quazi J .Organometallic Chem. 1967,7 321 336 J . A. McGinnety and M . J . Mays chromium prepared from tris(acetonitri1e)tricarbonylchromium and hexa-methylborazole has been reported as an air-stable complex which sublimes without decomposition at 91°.,08 Decacarbonyldirhenium reacts with N204 to give nitratopentacarbonylrhenium Re(C0)5N03.209 (b) Phosphorus Arsenic Antimony Bismuth. The range of metal complexes with organophosphines as ligands seems to be ever increasing. Their physico-chemical and spectroscopic properties and the kinetics of formation have received much attention; there have been many papers dealing with their use in effecting organic syntheses although there is not space to deal with this aspect here. The reaction of diphenylphosphine with metal carbonyls has been investigated ; mono- di- and tri-substituted derivatives of hexacarbonyl-molybdenum can be synthesised.A new type of sym-asym isomerism is postulated in the cis-disubstituted complex.210 X-ray structure determination has confirmed that the complex formed in the reaction of Ph,P-C6H,*CH,*CH:CH with Mo(CO) is Mo(CO),(Ph,P*C6H,*CH:CH-CH,) in which the olefin has isomerised and is co-ordinated to the metal in a cis-configuration.2" There are details of reactions between cyclic phosphines (RP), [R = Ph Me or Et; n = 4 or 51, and metal carbonyls.212 An X-ray structure determination confirms that the product isolated from the reaction between (EtP) and Mo(CO)~ is the complex Mo(CO),(PEt) in which ring expansion has taken place. The pentaphosphine ring is 1,3-co-ordinated to the metal atom.213 The molecules As,(NMe) and P,(NMe)6 act as non-chelating quadridentate ligands in reactions with nickel carbonyl in the same way as P406.214 The crystal structure of Bis(dimethy1arsine)tricarbonyl-o-phenyleneiron [Fe(CO),diars] (diars = dimethylarsine) shows that the iron atom is five-co-ordinate with a slightly distorted trigonal bipyramidal ge~rnetry.~ l S In the reaction of Re C(R)* CF CF (R = AsMe,) with Fe(CO) two complexes were isolated.One of formula Fe(CO)3L is similar to [Fe(CO) didrs] ; the other of formula [Fe(CO),],L has an unusual structure the essential features of which are shown in (4). The molecule contains two iron atoms with an unusually long Fe-Fe bond of 2 88 A. One iron atom is octahedrally co-ordinated and the other is five-co-ordinate.216 Organometallic phosphines of the type P[MMe 208 R.Prim and H. Werner. Angew. Chem. Internat. Edn. 1967,6,91. 209 C. C. Addison R. Davis and N. Logan Znorg. Chem. 1967,6,1926. 'lo J. G. Smith and D. T. Thompson J . Chem. SOC. (A) 1967,1694. 211 H . Luth M. R. Truter and (in part) A. Robson Chem Comm. 1967 738. 212 H. G. Ang and B. 0. West Austral. J . Chem. 1967,#) 1133. '" M. A. Bush V. R. Cook and P. Woodward Chem. Comm. 1967,630. '15 D. S. Brown and G. W. Bushnell Actu Cryst. 1967,22,296. '16 F. W. B. Einstein and J. Trotter J . Chem. SOC. (A) 1967 824. J. G. Riess and J. R. Van Wazer J . Orgunometallic Chem. 1967 8 347 Transition-M eta1 Carbonyls and Organometallic Complexes 337 (M = Si Ge Sn or Pb) form monosubstituted complexes Ni(CO)3L which are much more stable in air than the free ligand although they decompose at room temperature with the separation of metal2 ’’ Octacarbonyldicobalt reacts with triethylphosphine giving a mixture of carbonyl-bridged and non-bridged dinuclear complexes.21 * It is known that the reaction of organodiphosphines (R2P), with metal carbonyls leads to two types of bridged complexes containing either (i) M-P-P-M or (ii) M”‘M units.The silylphosphine Me,SiPPh, reacts R2 R2 R2 ‘P’ R2 with manganese and pentacarbonylrhenium halides under mild conditions to give type (ii) complexes and trimethylsilyl halide ; more vigorous conditions, however lead to the formation of trimers.2’9 Rhodium and iridium complexes of type (i) and (ii) have been prepared from tetraphenylphosphine and the metal carbonyl halides.The type (ii) derivative [RhCl(CO)PR,], can be isolated as the cis- or trans-isomer.220 The type (ii) complex [(CO),MoPEt212 reacts with triethylphosphine to give a single product of formula [E~,PMO(CO)~PE~~]~. X-Ray diffraction shows this to be a centrosymmetric molecule in which the two Et3P groups are substituted trans to each other; the two metal atoms and all four phos-phorus atoms lie in a plane.221 While an X-ray study of the type (ii) complex /p\ [ ( Z - C ~ H J N ~ P P ~ ~ ] ~ shows the molecule to contain a planar Ni’ ‘ Ni unit, \P/ P the corresponding cobalt complex [C5HSCoP(C6HS)2]2 contains a Co’ ‘Co framework in which the two planes defined by a cobalt atom and the two phosphorus atoms are inclined at 75”.This is attributed to the effect of a metal-metal bond in the cobalt complex.222 The symmetry of carbonyl-containing type (ii) species has also been inferred from a study of i.r. combination bands in the 2 x v(C0) region.223 The mass224 and Mo~sbauer~~’ spectra of a number of phosphido-bridged complexes of type (i) and (ii) have been recorded. The substitution of phosphines into x-cyclopentadienyl carbonyl complexes ’I7 H. Schumann and 0. Stelzer Angew. Chem Znternat. Edn. 1967 6 701. 218 G. Capron-Cotigny and R. Poilblanc atll. SOC. chim France 1967,1440. ‘19 E. W. Abel and I. H. Sabberwal J . Organometallic Chem. 1967,10,491. ’” W. Hieber and R. Kummer Chem Ber. 1967,100,148. ’” R. H. B. Mais P. G. Owston and D. T. Thomspon J .Chem. SOC. (A) 1967 1735. 222 J. M. Coleman and L. F. Dahl J . Amer. Chem SOC. 1967 SS 542. 223 P. S. Braterman and D. T. Thompson J . Organometallic Chem. 1967 10 P.ll. 22* B. F. G. Johnson J. Lewis J. K. Wilson and D. T. Thomspon J . Chem SOC. (A) 1967 1445; ”’ T. C. Gibb R. Greatrex N. N. Greenwood and D. T. Thompson J . Chem. SOC. (A) 1967. 1663. \P/ J. M. Miller ibid. p. 828 338 J. A. McGinnety and M. J. Mays of niobium,226 molybdenum and tungsten,227 manganese,228 and ironzz9 has been studied from a preparative viewpoint and conclusions about the relative n-acceptor strengths in thesez3' and otherz3' metal carbonyl com-plexes have been drawn on the basis of i.r. data. Substitution reactions of phosphine have also been studied kinetically. While replacement of olefin in (n-C,H,)Mn(C0)2~lefin,232 of phosphine (L) in cis- and trans-Mo(CO),L, (by d i p h ~ s ) ~ ~ and of carbonyl in Re(CO),X (X = halogen)234 are first-order reactions which are independent of the concentration of the substituting ligand replacement of olefin in Mo(CO),C8H12235 and of carbonyl in Mo(CO), (at high ligand concentration^)^^^ obeys a two-term rate law and is ligand-dependent.Trifluorophosphine complexes which show many resemblances to carbonyl complexes have been the subject of a review.237 Among new trifluorophosphine complexes to be prepared is [(PF,),Co(PF,)], which is the first complex to contain PF2 bridges.238 All possible substitution products of the type CoNO(CO)JPF,) - are obtained in approximately statistical proportions by the reaction of cobalt nitrosyl tricarbonyl with PF3239 and all the possible geometric isomers have been identified from i.r.spectra in the series Fe(CO),(PF,) - ,. These studies have been taken to indicate that PF n-bonds to about the same degree as C0.240 Tetrakisfluorophosphine derivatives of nickel(o) can be synthesised from (n-CSHJ2Ni and ligand often under mild conditions.241 The mass spectrum of Ni(PF,) has been reported :242 this complex reacts with alkoxides giving partial or complete replacement of -F by -OR.243 Pentafluorophenylphosphine complexes of rhodium palla-dium and platinum have been prepared; the n.m.r. spectra of MX2[P(C6FJ3 (M = Pd X = Br ; M = Pt X = Br or I) are temperature dependent providing evidence for restricted rotation of the ligands in these complexes.244 The relative positions of a series of tertiary phosphine and nitrogen donor-ligands (L) in 226 A.N. Nesmeyanov K. M. Anisimov N. E. Kolabova and A. A. Pasynskii Isv. Akad. Nauk. "' R. J. Haines R. S. Nyholm and M. H. B. Stiddard J . Chem. SOC. (A) 1967,94; P. M. Treichel, 22a C. Barbeau Canad. J . Chem. 1967,45 161. 229 A. N. Nesmeyanov Yu A. Chapovski L. I. Denisovich B. V. Lokshin and I. V. Polovyanuk, 230 W. Strohmeier and F. J. Miiller Z . Naturforsch. 1967,22 b.45 1 231 W. Strohmeier and F. J. Miiller Chem. Ber. 1967,100 2812. 232 R. J. Angelici and W. Loewen Inorg. Chem. 1967 6 682. 233 F. Zingales F. Canziani and F. Basolo J. Organometallic Chem. 1967 7 461. 234 F. Zingales M. Graziani and U. Belluco J . Amer. Chem. SOC.1967,89,256. 23s J. R. Graham and R. J. Angelici Znorg. Chem. 1967,6,2082. 236 F. Zingales M. Graziani F. Faraone and U. Belluco Inorg. Chim. Acta 1967 1 172. 237 T. Kruck Angew. Chem. Znternat. Edn. 1967,6,53. 238 T. Kruck and W. Lang Angew. Chem. Internat. Edn. 1967,6,454. 239 R. J. Clark Znorg. Chem. 1967,6299. 240 J. B. Pd. Tripathi and M. Bigorgne J . Organometallic Chem. 1967,9 307. 241 J. F. Nixon J . Chem SOC. (A) 1967 1136. 242 R. W. Kiser M. A. Krassoi and R. J. Clark J . Amer. Chem. SOC. 1967 89 3654. 243 T. Kruck and M. Hiiller Angew. Chem Internat. Edn. 1967,6,563. '*' R. D. W. Kemmit D. I. Nichols and R. D. Peacock Chem Comm. 1967 599. S.S.S.R. Ser. khim. 1966 2231. K. W. Barnett and R L. Shubkin J . Organometallic Chem. 1967,7,449. Doklady Akad.Nauk. S.S.S.R. 1967,174 1342 Transition-M eta1 Carbonyls and Organometallic Complexes 339 the spectrochemical series has been assessed by measuring the 4T2g +- ,A2, transition in the electronic spectrum of the series of complexes [Cr(NCS),L,] -. In general the tertiary phosphines have slightly higher-ligand-field strengths than the nitrogen donors.245 The multidentate phosphine tris(o-diphenylphosphinophenyl)phosphine? (qp) forms pentaco-ordinate complexes with iron@) and c o b a l t ( ~ ~ ) . ~ ~ ~ An X-ray crystal structure determination of [CoCl qp] [BPh,] shows a highly distorted trigonal bipyramidal co-ordination of cobalt. This distortion has been attributed to a Jahn-Teller effect as it is too large to be explained by a gain of crystal-field stabilisation energy or by spin-orbit coupling.247 Five-co-ordinate structures have also been proposed on the basis of electronic spectra e.s.r.and magnetic studies for low-spin cobalt(r1) complexes of formula [CoL,X]+ (L = d i p h ~ s ~ ~ ' or mixed P-S P-Se and P-As bidentate l i g a a d ~ . ~ ~ ~ ) In the octahedral chromium complexes [CrX qp] only three of the four phosphorus atoms are bonded to the chromium;250 on heating this complex to 240" under vacuum however it is converted to [Cr(CO),qp] in which the ligand is quadridentate. Oxidation of this with mild halogenating agents gives [Cr(CO),qp]+ which can be further oxidised to chromium(rr1) complexes in which the ligand is either ter- or q~adri-dentate.~" (EtO),P reacts with CoCl to form two different cobalt(1) complexes CoCl[P(OEt),], and CoCl[P(OEt),] which are respectively dia- and para-magnetic.Both absorb hydrogen to give Co[P(OEt),] as an unstable Some new complexes of rhodium(II1) with dimethylphenylphosphine have been prepared and their stereochemistry investigated by n.m.r. spectro~copy.~ Complexes of nickel@) with triphenylphosphine of formula NiX(PPh3) have been obtained; they dissociate with loss of a phosphine ligand in solution.254 Reaction of nickel(@ complexes of the type trans-Ni(PR,),(CN) with excess phosphine gives five-co-ordinate complexes Ni(PR,),(CN), in solution. One of these Ni(Et,Ph),(CN), has also been isolated in the solid state.255 The crystal structure of [Ni tap CNIC10 (tap = tris-(3-dimethylarsino-propy1)phosphine) shows that the cation approximates closely to a trigonal bipyramid and has (C,) symmetry with P and CN on the three-fold axis; the nickel is slightly displaced (towards phosphorous) out of the A~,-plane.~ 56 Similar five-co-ordinated nickel complexes with other tetradentate ligands have 24s M.A. Bennett R. J. H. Clark and A. D. J. Goodwin Inorg. Chem. 1967,6 1625. 246 M. T. Halfpenny J. G. Hartley and L. M. Venanzi J . Chem. SOC. (A) 1967 627; J. G. Hartley, 247 T. L. Blundell H. M. Powell and L. M. Venanzi Chem. Comm. 1967 763; M. J. Norgett, 248 W. D. Horrocks jun. G. R. Van Hecke and D. D. Hall Inorg. Chem. 1967,6,694. 249 G. Dyer and D. W. Meek J . Amer. Chem SOC. 1967,89 3983. I. V. Howell L. M. Venanzi and D. C. Goodall J . Chem SOC. (A) 1967,395. I. V. Howell and L. M. Venanzi J .Chem. SOC. (A) 1967 1007. D. G. E. Kerfoot and L. M. Venanzi Inorg. Chim Act6 1967,1 145. J. H. M. Thornley and L. M. Venanzi J . Chem SOC. (A) 1967,540. 252 M. E. Vol'pin and I. S. Kolomnikov Doklady Akad. Nauk. S.S.S.R. 1966 170 1321. 253 P. R. Brookes and B. L. Shaw J . Chem. SOC. (A) 1967 1079. *" L. Porri M. C. Gallazzi and G. Vituli Chem. Comm. 1967,228. "' P. Rigo C. Pecile and A. Turco Inorg. Chem. 1967,6 1636. D. L. Stevenson and L. F. Dahl J . Amer. Chem SOC. 1967,89,3424 340 J . A. McGinnety and M . J . Mays been preparedzs7 and other nickel complexes containing ter-2s8 and bi-dentatezs91igands are also frequently five-co-ordinate. The crystal structure of [Pd tpascl] clo 3,C6H6 [ tpas = o-phen ylenebis-( o-dimet h ylarsinophen yl methylarsine)] reveals a square-pyramidal co-ordination of the palladium atom.It is suggested that this is the preferred geometry for five-co-ordinate palladium(r1) and platinum(I1) complexes in the absence of steric requirements of the ligands or very strongly multiple-bonded metal-ligand bonds.260 Complexes of palladium(I1) with a number of polydentate phosphorus-sulphur ligand has been described.z61 Diethyl hydrogen phosphite reacts with Kz[PdCl,] to give a complex, (PdC1[P(OEt)20][P(OEt),0H)2 in which the phosphine is bonded in a tautomeric form ;z62 similar complexes of platinum have also been described.263 Group VI Derivatives.-(a) Oxygen. Dicarbonyl P-diketonate complexes of rhodium@) and iridium(1) show dichroic properties in the crystalline state, suggesting weak metal-metal interactions.Crystal structure determinations on several of these complexes show the molecular skeleton to be essentially planar with chains of metal atoms perpendicular to the plane; the distance between the metal atoms is increased by the introduction of trifluoromethyl substituent groups into the P-diketone ligand as a consequence of increased ligand-ligand repulsive forces.264 Related rhodium and iridium complexes of some Schiff bases of acetylacetone have been described.265 (b) Sulphur and selenium. The chemistry of sulphur-containing metal carbonyls has been reviewed.266 Alkylthiotin compounds react with penta-carbonyl-manganese and -rhenium halides giving the tricarbonyl species, [RSM(CO),],. A trimeric structure was originally suggested for these com-plexes on the basis of molecular weight measurements in solution.Subsequent mass spectroscopic studies however show that tetramers are present in the gas phase; only for [PhSRe(CO),] can a trimer also be identified.267 A repetition of the molecular weight measurements in solution indicate that the value of n depends on the solvent. Selenium analogues of the above complexes have been synthesised,268 also some perfluoroalkyl selenium complexes of iron (Z-C~H,)F~(CO)~S~R (R = CF3 C2F5 or C3F7) which are mono-r n e r i ~ . ~ ~ ~ 257 G. S. Benner and D. W. Meek Znorg. Chem. 1967,6 1399; L. Sacconi and I. Bertini J . Amer. Chem. SOC. 1967,89,2235; G. Dyer and D. W. Meek Znorg. Chem. 1967 6 149. 2s8 M. 0. Workman G. Dyer and D. W. Meek Znorg. Chem. 1967.6 1543.2s9 L. Di Sipio L. Sindellari E. Tondello G. De Michelis and L. Oleari Co-ordination Chem. Rev., 1967 2 129; T. D. Dubois and D. W. Meek Znorg. Chem. 1967,6 1395. T. L. Blundell and H. M. Powell J . Chem SOC. (A) 1967 1650. 261 G. Dyer M. 0. Workman and D. W. Meek Inorg. Chem. 1967,6 1404. 262 G. A. Levishina A. D. Troitskaya and R. R. Shagidullin Russ. J . Znorg. Chem. 1966 11 985. 263 A. Pidcock and C. R. Waterhouse J . Inorg. Nuclear Chem. Letters 1967,487. 264 N. A. Bailey F. Coates G. B. Robertson F. Bonati and R. Ugo Chem. Comm. 1967 1041. 26s F. Bonati and R. Ugo J . Organometallic Chem. 1967,7 167. 267 M. Ahmad G. R. Knox F. J. Preston and R. 1. Reed Chem. Comrn. 1967 138; K. Edgar, 268 E. W. Abel B. C. Crosse and G. V. Hutson J . Chem. SOC. (A) 1967 2014.269 N. Welcman and P. Rosenbuch Israel J . Chem. 1967,5 lop. E. W. Abel and B. C. Crosse Organometallic Chem Rev. 1967 2 443. B. F. G. Johnson J. Lewis I. G. Williams and J. M. Wilson J . Chem SOC. (A) 1967 379 Transition-M eta1 Carbonyls and Organometallic Complexes 341 X-Ray structure analyses of a number of different types of sulphur-bridged metal carbonyl complexes have been published. In Fe,(CO),SO2 the two iron atoms are bridged by the sulphur atom and a metal-metal bond.270 The sulphur atom in SCO,(CO)~ bridges three metal atoms forming the apex of a tetrahedrunz7' and giving the complex a structure similar to that of MeCCo,(CO) ;272 whilst in [MeSFe2(CO),],S there is a central sulphur atom which is tetrahedrally co-ordinated by four iron atoms.273 The structure of [SCO~(CO)~]~S is related to that of SCO,(CO)~ in place of two cis equatorial carbonyl groups from each tetrahedron there is a disulphide group which symmetrically bridges the two S C O ~ tetrahedra through four cobalt atoms,274 i.e.co-S-CO co-s-co. I l l The reaction of thiophenol with CO,(CO)~ has led to some new sulphur-containing cobalt cluster compounds of unknown structure such as (P~S)SCO~(CO)~ and (PhS)(S)C06(C0)10.275 Complexes containing MetaLMetal Bonds.-Some complexes which contain metal-metal bonds e.g. polynuclear carbonyls have been dealt with in previous sections and hence will not be referred to again. Bonding in co-ordination compounds containing metal-metal bonds has been reviewed.276 An i.r. study shows that complexes of the composition [(n-C,H,)M(CO),], (M = Fe Ru or 0 s ) exist in solution in two isomeric forms the proportions of which are temperature dependent.The 'low temperature' form contains two bridging and two non-bridging carbonyl groups. while the 'high tempera-ture' form contains no bridging groups.'- Thc cnthalpy and entropy differences between the two forms have been determined; the non-bridged form becomes progressively more favoured from iron to osmium.278 In solution the cyclo-pentadienyl groups are cis to each other in both forms of the complexes but an X-ray structure analysis shows that in the crystal the cyclopentadienyl groups in [(~-C,H,)RU(CO)~]~ as in [(n-CSHs)Fe(CO),], are trans and that the molecule is entirely in the bridged form.279 Two related complexes have been synthesised which contain a single CO bridge; (x-CSHs)2V2(CO) appears from i.r.data to exist in a cis form in solution280 while the crystal structure of 270 J. Meunier-Piret and M. van Meersche Bull. SOC. chim. belges 1967 76 374. 271 D. L. Stevenson V. R. Magnuson and L. F. Dahl J . Amer. Chem. SOC. 1967,89 3727. 272 P. W. Sutton and L. F. Dahl J . Amer. Chem. SOC. 1967,89 261. 273 J. M. Coleman A. Wojcicki P. J. Pollick and L. F. Dahl Inorg. Chem. 1967 6 1236. 274 D. L. Stevenson V. R. Magnuson and L. F. Dahl J . Amer. Chem. SOC. 1967 89 3727. 2 7 5 E. Klumpp G. Bor and L. Marko Chem. Ber. 1967,100 1451. 276 B. J. Bulkin and C. A. Rundell Co-ordination Chem. Rev. 1967 2 371. 277 R. D. Fischer and A. Vogler J . Organometallic Chem. 1967 7 135; F.A. Cotton and 2 7 8 K. Noack J . Organometallic Chem. 1967 7 151. 279 0. S. Mills and J. P. Nice J . Organometallic Chem. 1967 9 339. G. Yagupsky Inorg. Chem. 1967,6 15. E. 0. Fischer and R. J. J. Schneider Angew. Chem. Internat. Edn. 1967,6 569 342 J . A. M cGinnety and M . J . Mays (n-C,H,),Rh,(CO) shows the molecule to be in a trans form in the solid.28’ [C,(Me),Fe(CO),], however is probably in a trans bridged form even in solution.282 The farir. spectra of metal-metal bonded complexes show bands which may often be assigned as being principally due to metal-metal stretching vibrations.283 Quadruple and other multiple metal-metal bonds have been discussed the~retically.,~~ Two cyclopentadienyl complexes of molybdenum have been synthesised which probably contain Mo-Mo triple bonds.282* 28 The structures of some metal ‘cluster’ compounds have been determined by X-ray analysis.In the molecule (R-C,H,)~M~,(NO) there is a triangle of manganese atoms with one nitrosyl group along each edge and one nitrosyl group which bridges all three metal atoms;286 a similar arrangement is found in (~c-C,H,),R~,(CO) except that there is no triply-bridging group.28 A regular tetrahedron of metal atoms is present in Ni4(C0)6[P(C,H4CN)3],,288 and probably also in the new copper(0) complex [ P ~ P C U ] ~ ~ ~ ~ Some phosphine-gold complexes such as [Au,diphos,X,] and (Au6[P(Ph2Et),],}Y (Y = C104 PF6 or BPh4) have been synthesised and are postulated to contain gold clusters of up to six atoms.290 Complexes containing covalent Pt-Cu Pt-Au and Pt-Hg bonds have been prepared from Pt(PPh,) and the appropriate metal halide.29‘ The exchange of Hg[Co(CO),] with zinc and cadmium metal takes place readily at room temperature providing a convenient route to the zinc and cadmium analogues.292 The X-ray analyses of Z ~ [ C O ( C O ) ] ~ ~ ~ ~ and H~[CO(CO),]~~’~ show the presence of a linear Co-M-Co chain in both molecules.The Hg-Co bond length (2.50 A) may be compared with that in the 1 1 adduct between (n-C,H,)Co(CO) and HgC12295 (2’58 A) in which the mercury atom is three-~o-ordinate.’~~ The crystal structure of (BrHg),Fe(CO) has also been reported.297 Examples of insertion reactions involving metal-metal bonded complexes are the insertion of SnI, Ge12 and SO2 into [Crz(CO)lo]2- and [W2(CO)10]2-’’’ 0.S. Mills and J. P. Nice J . Organometallic Chem. 1967 10 337. ’” R B. King and M. B. Bisnette J . Organometallic Chem. 1967,8 287. P. N. Brier A. A. Chalmers J. Lewis and B. Wild J . Chem. SOC. (A) 1967,1889; N. A. D. Carey and H. C. Clark Chem Comm. 1967,292. 284 F. A. Cotton Rev. Pure and Appl. Chem. 1967,17,25. 285 R. B. King Chem. Comm. 1967 986. ”’ 0. S. Mills and E. F. Paulus J . Organometallic Chem. 1967,10 335. ’” M. J. Bennett F. A. Cotton and B. H. C. Winquist J . Amer. Chem. SOC. 1967,89,5366. R. C. Elder F. A. Cotton and R. A. Schunn J . Amer. Chem. SOC. 1967 SS 3646. A. J. Layton R. S. Nyholm G. A. Pneumaticakis and M. L. Tobe Nature 1967 214 1109. F. Cariati L. Naldini G. Simonetta and L. Malatesta Inorg. Chim Acta 1967,1,24; ibid. 315. 291 A.J. Layton R. S. Nyholm G. Pneumaticakis and M. L. Tobe Chem and I d . 1967 465; 292 J. M. Burlitch J . Organometallic Chem. 1967,9 P. 11. 293 B. Lee J. M. Burlitch and J. L. Hoard J . A m . Chem. SOC. 1967,89,6362. 294 G. M. Sheldrick and R. N. F. Simpson Chem. Comm. 1967 1015, 295 D. J. Cook J. L. Dawes and R. D. W. Kemmit J . Chem SOC. (A) 1967 1547. 296 1. N. Nowell and D. R. Russell Chem Comm. 1967,817. ”’ H. W. Baird and L. F. Dahl J . Organometallic Chem. 1967 7 503. M. C. Baird J . Inorg. Nuclear Chem Letters 1967 29 367 Transition-M eta1 Carbonyls and Organometallic Complexes 343 to give e.g. [(CO)SMSn12M(CO)S]2 - and [(CO)5MS02M(CO),]2 - 298 also the reaction of CS2 with K6[C~2(CN)lo] to give a 1:l adduct which it is suggested contains an -SCS- group bridging the two cobalt atoms.299 @-Bonded Organometallic Compounds.-A number of o-bonded phenyl-ethynyl derivatives of transition metals have been studied.The structures of phenylethynyl(isopropylamine)gold(~)~~~ and trans-bis(phenylethynyl)bis(tri-ethylphosphine)nicke1(11)~'~ have been determined by X-ray crystallography. The metal-carbon bond lengths in both these compounds are short pre-sumably due to d -+ ps interactions and the acetylenic carbon-carbon bond lengths are normal for a triple bond. Phenylethynyl derivatives of titanium302 and iron303 have been prepared. The pentacyanocobaltate(1r) ion reacts with acetylenes to form trans-disubstituted 01efins.~'~ The fascinating chemistry of carbene derivatives of transition metals has been the subject of much work.The preparation and properties of phenyl-methoxycarbene and methylmethoxycarbene complexes of chromium molyb-denum tungsten and manganese have been reported in Penta-carbonyl(methy1methoxycarbene)chromium reacts with ammonia primary and secondary amines306 by the general equation : Cr(CO) *C(OMe)Me + R'R2NH - Cr(CO)5 *C(NR1R2)Me + MeOH The structure of pent acar bony1 [met hy l(met h y1amino)car benelchromium has been determined by X-ray ~rystallography.~'~ The reactions of pentacarbonyl-(methy1methoxycarbene)chromium with substituted hydrazines308 and iso-cyanides3" have been reported. In some compounds containing a metal-carbon o-bond there is considerable evidence for secondary interactions. In acetylcarbonylcyclopentadienyltri-phenylphosphineiron d -+ pn bonding results in a build-up of charge on the oxygen atom of the acetyl group and reversible protonation can occur at this site to form a carbene A carbene intermediate may also be involved in the reaction of methoxymethyl derivatives of iron with proton acids such as hexafluorophosphoric acid.3 In the proposed reaction scheme, methanol is cleaved off and the carbene intermediate disproportionates ; one of the products is an ethylene n-complex of iron.Some transition-metal alkyl 19' J . K. Ruff Znorg. Chem. 1967,6,2080. 299 T. Mizuta T. Suzuki and T. Kwan J . Chem. SOC. Japan 1967,88 573. 300 P. W. R. Corfield and H. M. M. Shearer Acta. Cryst. 1967,23 156. '01 W. A. Spofford P. D. Carfagna and E. L. Amma Znorg. Chem. 1967,6 1553; G. R. Davies, '02 H.Kopf and M. Schmidt J . Organometallic Chem. 1967,10,383. 303 R. Nast K. W. Kriiger and G. Beck Z . anorg. Chem. 1967,350 177. 304 M. E. Kimball J. P. Martella and W. C. Kaska Inorg. Chem. 1967 6,414. 305 E. 0. Fischer and A. Maasbijl Chern. Bcr. 1967.100. 7445 306 J. A. Connor and E. 0. Fischer Chem. Comm. 1967 1024. 307 P. E. Baikie E. 0. Fischer and 0. S. Mills Chem. Comm 1967 1199. 308 E. 0. Fischer and R. Aumann Angew. Chem. Internat. Edn. 1967,6 181. ' 0 9 R. Aumann and E. 0. Fischer Angew. Chem. Internat. Edn. 1967,6,879. M. L. H. Green and C. R. Hurley J . Organometallic Chem. 1967,10 188. 311 M. L. H. Green M. Ishaq and R. N. Whiteley J . Chem SOC. (A) 1967 1508. R. H. B. Mais and P. G. Owsten J . Chem SOC. 1967 1750 344 J . A. M cGinnety and M . J .Mays derivatives lose a hydride ion when treated with triphenylmethyl salts and this reactivity may be due to interaction between the metal atom and the b-carbon atom. In earlier work it was reported that transition-metal ethyl derivatives react in this way to form olefin complexes.312 Hydride abstraction also occurs in the reaction of (CHz)3[Fe(C0)z(n-C,Hs)]z with triphenylmethyl salts;313 the product can be considered to be a carbonium-ion salt or even a n-ally1 complex in which the ally1 group symmetrically bridges the iron atoms. The acidity of carboxymethyl transition-metal complexes is sometimes anomalously low. Comparison of the structure of one of these weak acids with a normal acid shows some significant differences and it is suggested that this provides further evidence for metal-b-carbon interaction^.^ l4 Tetra-alkyl and aryl derivatives of titanium can be prepared by the reaction of the appropriate Grignard reagent with titanium tetrachloride in the presence of pyridine.31 The thermal decomposition of tetramethyltitanium has been e~amined.~ l6 Pentacarbonylmethylmanganese reacts with carbon monoxide to form acetylpentacarbonylmanganese ; this reaction proceeds by methyl migrati~n.~" Tricarbonylcyclopentadienylmethylmolybdenum reacts with phosphorus-containing ligands to form the corresponding acetyl complexes by a mechanism involving methyl migration ;31 decarbonylation from the acetyl group then occurs and dicarbonylcyclopentadienyltriphenylphosphine-methylmolybdenum can be isolated from the reaction rni~ture.~" The 1 -aza-2-ferracyclohexadiene ring system was prepared by the insertion reaction of NN-dichloro-p-toluenesulphonamide with a ferracyclopentadiene compound.320 Aryl ( = Ar) derivatives of formula Fe (rC,H,)(CO),(Ar) have been prepared by the reaction of 'onium' salts with NaFe (n-C,HS)(CO)z ;321 the polarography and i.r.absorption of these aryl compounds and phosphine-substituted derivatives have been examined to determine the electronic effects of substituents in such complexes.32z The visible absorption and e.s.r. spectra of a number of organo-cobalt compounds have been measured ;323 the compounds of general formula CoX(R)(PEt,Ph) (X = halogen R = methyl or pentachlorophenyl) have tetrahedral co-ordination around cobalt in contrast to the dialkyl compounds ''' M.L. H. Green and P. L. I. Nagy J . Organometallic Chem. 1963,1 58. 313 R. B. King and M. B. Bisnette J . Organometallic Chem. 1967,7 311. '14 M. L. H. Green J. K. P. Ariyaratne A. M. Bjerrum M. Ishaq and C. K. Prout Chem. Comm., '15 K. S. Boustany K. Bernauer and A. Jacot-Guillarmod Helu. Chim. Acta 1967 50; 1305. 'I6 G. A. Rasuvaev V. N. Latyaeva and A. V. Malysheva Dokludy Akud. Nauk. S.S.S.R. 1967, 'I' K. Noack and F. Calderazzo J . Organometallic Chem. 1967,10 101. '18 P. J. Craig and M. Green Chem. Comm. 1967 1246. '19 K. W. Barnett and P. M. Treichel Inorg. Chem. 1967,6 294. ''O E. H. Braye and W. Hiibel J . Organornetallic Chem. 1967 9 370. ''I A. N. Nesrneyanov Yu. A. Chapovsky I. V. Polovyanuk and L. G. Makarova J . Organo-322 A. N. Nesmeyanov Yu.A. Chapovsky L. I. Denisovitch B. V. Lokshin and I. V. Polovyanyuk, 323 K. Matsuzaki and T. Yasukawa J . Phys. Chern. 1967,71 1160. 1967,430. 173 1353. metallic Chem. 1967,7 329. Doklady Akud. Nauk. S.S.S.R. 1967 174 1342 Transition-M eta1 Carbonyls and Organometallic Complexes 345 CoR2(PEt2Ph), which are square-planar. The o-lithium derivative of NN-dimethylbenzylamine reacts with cobalt(I1) chloride to form the unreactive complex Co(o-C6H4-CH2 -NMe2), which contains three C O X bonds and is stabilised by the additional co-ordination of the three nitrogen atoms to co-balt.324 Alkyl derivatives of cobalt compounds have received much attention because of their analogies with vitamin BI2. Alkylcobalt chelates have been prepared where the chelating reagent is NN-bis(salicyla1dehyde)ethylenedi-imine.They can be prepared by the reaction of the cobalt(II)-chelate with a Grignard reagent325 or by the reduction of the cobalt(Ir)-chelate using sodium sand326 or sodium amalgam327 followed by addition of alkyl halides. The cobalt-carbon bond in these compounds can be cleaved by irradiation in alcohol solution in the presence of carbon monoxide;328 the original alkyl group is lost and the product contains a - CO OR group formed from carbon monoxide and a fragment of the solvent. Using another chelating agent, 1,3-bis(3-hydroxyiminobut-2-ylideneamino)propane ionic alkylcobalt com-pounds can be prepared and these are soluble in water.329 Alkylrhodium complexes are formed by the reaction of chlorotris(tripheny1-phosphine)rhodium(I) with Grignard reagents.330 A range of methyl deriva-tives of iridium(Ir1) have been prepared and their physical properties reported.33 The structure of di-~-chloro-dichlorodimethyltetracarbonyldi-iridium(~~~) has been determined by X-ray crystallography;332 the chlorine bridges are not symmetrical and this is ascribed to the transeffect of the methyl groups.Hydridodichlorotris(dimethylsulphoxide)i~dium(I~I) catalyses the transfer of hydrogen from propan-2-01 to benzylideneacetophenone and dichloro(benzy1-acetophenone)bis(dimethylsulphoxide)iridium was isolated from the reaction mixture ;333 benzylacetophenone is connected to iridium by an Ir-C a-bond and by co-ordination frpm the ketonic oxygen atom.334 The bond energy of the Pt-C a-bond in diphenylbis(tripheny1phosphine)-platinum has been shown to be not lass than 60 kcal./mole by a calorimetric study of the reaction of this compound with hydrogen chloride in d i ~ x a n .~ ~ trans-Halogenomethylbis(triphenylphosphine)platinum(~~) reacts with hydro-gen chloride to form methane and trans-chlorohalogenobis(tripheny1-phosphine)platinum(rI) ; a kinetic study suggests that the mechanism involves formation of the six-co-ordinate adduct followed by slow elimination of methane.336 Trimethylplatinum(1v) halides react with aqueous silver per-324 A. C. Cope and R. N. Gourley J . Organometallic Chem. 1967,8 527. ’” G. Costa G. Mestroni and L. Stefani J . Organometallic Chem. 1967 7 493. 326 F. Calderazzo and C. Floriani Chem. Comm. 1967 139. 32’ G. Costa and G.Mestroni Tetrahedron Letters 1967 1783. G. Costa and G. Mestroni Tetrahedron Letters 1967 1781. ’*’ G. Costa and G. Mestroni Tetrahedron Letters 1967,4005. ”O W . Keim J . Organometallic Chem. 1967,8 P. 25. 331 B. L. Shaw and A. C. Smithies J . Chem SOC. (A) 1967 1047. 332 N. A. Bailey C. J. Jones B. L. Shaw and E. Singleton Chem. Comm. 1967 1051. ’” J. Trocha-Grimshaw and H. B. Henbest Chem. Comm. 1967 544. 334 M. McPartlin and R. Mason Chem. Comm. 1967,545. ”’ S. J. Ashcroft and C. T. Mortimer J . Chem SOC. (A) 1967,930. 336 U. Belluco M. Giustiniani and M. Graziani J . Amer. Chem. SOC. 1967 89 6494 346 chlorate yielding solutions which contain the aquated ion [PtMe,(H,O), Six-co-ordinate derivatives of tetramethylplatinum have been prepared.,,' The structure of trimethyl(salicylaldehydato)platinum(rv) has been deter-mined by X-ray crystallography.The molecules are dimeric six-co-ordinate and centrosymmetric; the phenolic oxygen atoms link the two platinum atoms and a delocalised bonding scheme is consistent with the equality of the four Pt-O(pheno1) interatomic distances.339 Further information about the relationship between reactivity and mode of bonding of acetylacetone (acac-H) has been gained by a study of the reactions of acids with K[PtXacac,] (X = C1 or Br,) and KCPtacac,]. In KCPtXacac,] one acetylacetone ligand is conventionally bound with bidentate oxygen co-ordination and the second is bound by a single o-bond from carbon to platinum; this compound reacts with strong aqueous acids and the yellow non-ionic solid [PtHXacac,] is precipitated.Protonation occurred at a carbonyl group of the C-bonded acetylacetone. The modification of bonding consequent upon this protonation is not clear and it was suggested that this acetylacetone is bonded as a n-complex of the enolic form of acetylacetone. However the equivalence of the methyl protons in the n.m.r. spectrum is not consistent with the simplest idea of donation from a two-centre n-bond. In KCPtacac,] one acetylacetone is bound by bidentate oxygen co-ordination and two are bound by a Pt-C o-bond; the reaction of this compound with acids varies with the acid. With hydrochloric or hydrobromic acid the product has the composition PtX2(C10H1403) (X = C1 or Br) and this contains a bicyclic dienyl ring formed by condensation of the two C-bonded acetylacetone groups.With acids such as aqueous sulphuric acid KCPtacac,] forms a polymeric compound of composition Pt(C,H,O,) which reacts with pyridine to form the crystalline compound Pt acac,,py ; this has square-planar co-ordination around platinum with both acetylacetone groups bound by a Pt-C o-b~nd.,~' Palladium(I1) chloride reacts with NN-dimethylallylamine in alcoholic solution to form di-~-chloro-bis(2-alkoxy-3-NN-dimethylaminopropyl)di-palladium; the carbon skeleton of the ally1 group is substituted at the 2-position by the solvent and a Pd-4 o-bond is formed at the carbon atom furthest from nitrogen. 341 @-Bonded Fluorocarbon Complexes.-These complexes are considered separately from other o-bonded organometallic complexes because of the significantly different properties of saturated fluorocarbon groups compared to other alkyl groups.The greater stability and shorter metal-carbon distances of fluoroalkyl complexes suggests there is d - o* back-donation from the metal to the fluoroalkyl ligand. The reaction of tetrafluoroethylene with octacarbonyldicobalt has been J . A. M cGinnety and M . J . Mays 337 G. E. Glass and R. S. Tobias J . Amer. Chem. SOC. 1967,8!3 6371. 338 J. D. Ruddick and B. L. Shaw Chem. Comm. 1967,1135. 339 M. R. Truter and R. C. Watling J . Chem SOC. (A) 1967 1955. 340 D. Gibson J. Lewis and C. Oldham J . Chem SOC. (A) 1967,72. 341 A. C. Cope J. M. Kliegman and E. C. Friedrich J . Amer. Chem SOC. 1967,89,287 Transition-M eta1 Carbonyls and Organometallic Complexes 347 studied in detail.,, The initial step is insertion to form (CO),Co -CF2 CF Co(CO), which loses carbon monoxide to form (~c),Co( > Co(CO) which reacts with more octacarbonyldicobalt to CF CF, P b form CF -C Co,(CO)9 and CoF(CO) ; this last compound decomposed before isolation but the other compounds ca.n be isolated.This can be compared with the reaction of tetrafluoroethylene and pentacarbonyliron in which a weak wcomplex Fe(CO),(C,F,) is formed.343 X-Ray crystallographic studies have shown there is a short metal-carbon bond in tetrafluorethyl derivatives of and iron3,’. ! similar shortening is observed in tetracarbonyl-hexafluorobut-2-ene iron formed by the reaction of hexafluorobutadiene with pentacarbonyliron and dodecacarbonyltri-iron ; in this compound the co-ordination around iron is octahedral with iron bound to the 1- and 4-carbon atoms of the butene skeleton by a - b ~ n d s .~ ~ ~ Hexafluorobutadiene reacts with octacarbonyldicobalt to form diamagnetic CO,(C,F~)(CO)~ which reacts with triphenylphosphine to form paramagnetic CO,(C,F,)(C~)~(P~,P)~ ; in both of these cobalt compounds the butadiene is n-bonded to the two metal atoms but in the former compound there is also a metal-metal bond:347 Hexafluorobutadiene undergoes an insertion reaction with MH(CO) (M = Mn or Re). With the rhenium compound 1,4-addition of the hydride occurs, followed by a 1,3-fluorine shift and CHF *CF -CF:CF*Re(CO) can be isolated. This is one of the reactions that occurs with the manganese com-pounds but 1,3- and 1,2-addition also occur.348 Dicarbonylcyclopentadienylcobalt reacts with heptafluoropropyliodide to form CoI(n-C5H5)(C,F7)(C0) and [COI(WC~H,)(C,F~)]~ the proportion of the latter increasing as the reaction temperature increases.CoI(.n-C,H,)(C,F7) (CO) reacts with silver perchlorate to form silver iodide and a red solution.349 The red solution reacts with NaX to form CoX(n-C,H,)(C3F7)(CO) (X = C1 or Br) and to form polymeric [CoX(~-C,H,)(C,F,)J,(X = CN or SCN). The reactions of decafluorobenz-hydryl bromide (C6F,)2CHBr with carbonyls of iron molybdenum and manganese have been studied; a major product in all cases is (C6F,),CH * CH(C6Fs)2.3 Dichlorobis(triethylphosphine)nickel(Ir) reacts with trifluorovinylmagnesium bromide to form the mono- and di-vinyl complexes.The analogous platinum 342 B. L. Booth R. N. Haszeldine P. R. Mitchell and J. J. Cox Chem. Comm. 1967 529. 343 R. Fields M. M. Germain R. N. Haszeldine and P. W. Wiggans Chem. Comm. 1967 243. 344 J. B. Wilford and H. M. Powell J . Chem SOC. (A) 1967,2092. 345 M. R. Churchill Znorg. Chem. 1967,6 185. 346 P. B. Hitchcock and R. Mason Chem Comm. 1967 242. 347 R. L. Hunt D. M. Roundhill and G. Wilkinson J . Chem. SOC. (A) 1967,982. 348 B. W. Tattershall A. J. Rest M. Green and F. G. A. Stone Angew. Chem. Internat. Edn. 1967, 349 P. M. Treichel and G . P. Werber J . Oryanometallic Chem. 1967,7 157. 6 878. M. I. Bruce J . Organometallic Chem. 1967 10,495 348 J. A. M cGinnety and M. J. Mays and palladium complexes were similarly prepared351 and the stability of these complexes decreases in the order Pt > Pd > Ni.Pentafluorophenyl com-plexes of transition metals are more thermally stable than the non-fluorinated phenyl complexes; however this increase in stability is not reflected in a cor-responding shortening of the metal-carbon bond length at least for two nickel compounds the structures of which have been determined by X-ray crystallo-graph^.^^^ The mass spectra of some fluorocarbon derivatives of transition metals have been reported. Ally1 Complexes.-The ‘H n.m.r. spectra of many n-ally1 complexes exhibit a strong temperature dependence. A number of mechanisms have been pro-posed to explain this phenomenon and it seems likely that no single explanation can be used for all cases. There is one example354 where there is evidence for two symmetrical n-ally1 conformers at low temperatures.The spectrum becomes averaged at higher temperatures and is still typical of a symmetrical n-ally1 group; the syn- and anti-protons of the CH2 units are not equivalent at any temperature. This is most simply explained by supposing that one conformer changes to the other by rotation either about a vector from the metal to the allyl group or about a vector in the plane of the three carbon atoms of the allyl group. Another and quite distinct phenomenon involves the averaging of the syn- and anti-protons. The low temperature spectrum is typical of a symmetrical n-ally1 group i.e. AM,X, and the high temperature spectrum is of the type 356 A slight variation on this latter phenomenon involves compounds in which the allyl group is thought to be asymmetrically n-bonded; the four protons of the two CH groups are all different at low temperature357.358 and at high temperature they can all become equivalent. The ease of equilibration of the syn- and anti-protons in complexes of general formula RhC12(n-C4H,)L increases as L becomes a better donor,355 e.g. when L = Ph,P the protons equilibrate at a lower temperature than when L = Ph3Sb. Addition of a free ligand to a solution of [PdCl(n-C,H,)] results not only in more rapid equilibration but in the case of triphenylphosphine also in the appearance of weak absorptions in the i.r. spectrum which were attri-buted to a 0-ally1 group.359 From this evidence the most probable mechanism for the equilibration involves the formation of an intermediate o-ally1 complex.The first report of allyl derivatives of titanium has been made;360 dichloro-dicyclopentadienyltitanium(1v) reacts with excess allyl Grignard reagents to form allyldicyclopentadienyltitanium(Irr) which is monomeric and para-magnetic. The i.r. absorption spectrum indicates that the allyl and cyclo-’” A. J. Rest D. T. Rosevear and F. G. A. Stone J . Chem. SOC. (A) 1967 66. 352 M. R. Churchill T. A. O’Brien M. D. Rausch and Y. F. Chang Chem. Comm. 1967,992. 353 R. B. King J . Amer. Chem SOC. 1967,89,6368. 354 A. Davison and W. C. Rode Inorg. Chem. 1967,6,2124. ”’ K. Vrieze and H. C. Volger J . Organometallic Chem. 1967,9 537. 356 J. K. Becconsall B. E. Job and S. O’Brien J . Chem. SOC. (A) 1967,423. ”’ W. B.Wise D. C. Link and K. C. Ramey Chem. Comm. 1967,463. ”* J. Powell and B. L. Shaw J . Chem. SOC. (A) 1967 1839. 3 5 9 F. A. Cotton J. W. Faller and A. Musco Inorg. Chem. 1967,6 179. 360 H. A. Martin and F. Jeilinek J . Organometallic Chem. 1967,8 115 Transition-M eta1 Carbonyls and Organometallic Complexes 349 pentadienyl ligands are x-bonded. x-ally1 complexes of molybdenum and tungsten are synthesised by the reaction of allyl halides with substituted carbonyl~,~ 61 e.g., C3H,C1 + Mo(CO) bipy -+ MoCl(C,H,)(CO,) bipy + 2CO The halide in these non-ionic solids can be displaced in the presence of anions such as thiocyanate and ionic complexes are formed. o-Allylpentacarbonylmanganese(1) can react with strong proton acids to form two types of With perchloric acid the product isolated is the perchlorate salt of the cation [(x-CH *CH CH2)Mn(CO)5 '3; but with acids, HA where the anion can act as a donor to the metal the x-propene cation is formed the propene is then displaced and the product isolated is MnA(CO),.o-Allylpentacarbonylmanganese(1) reacts with sulphur dioxide to form a rearranged e.g. [Mn(CO),(CH,*Ck:CH*CH,)] +SO -+ Mn(CO),[S0,-CH(CH3)*CH:CHz] (x-Allyl)bis(triphenylphosphine)rhodium(I) is formed by the reaction of chlorotris(triphenylphosphine)rhodium(I) with allylmagnesium chloride. The n.m.r. spectrum is typical of a symmetrical x-ally1 complex and no equilibration of the syn- and anti-protons occurs either by raising the temperature to 120" or by addition of excess triphenylpho~phine.~~~ Chlorotris(tripheny1phosphine) rhodium(1) reacts with allyl halides to form x-ally1 complexes of rhodium(n1) by the general equation,365 where R = Me H; X = C1 Br; L = Ph,M where M = P As Sb.The struc-ture of di-p-chloro-tetra-x-allyldirhodium(II1) has been determined by X-ray crystallography ;366 the molecule is centrosymmetric and the allyl groups are asymmetrically x-bonded. x-Ally1 complexes of palladium are formed by the reaction of palladium(r1) halide with butadiene in acetic acid in the presence of copper(I1) and lithium acetates.367 Palladium(I1) chloride catalyses the dirneri~ation,~~ and isomerisa-t i ~ n ~ ' of olefins and x-allylpalladium complexes can be isolated from the reaction mixture. Mercury reduces di-p-chlorobis-x-allyldipalladium(1I) to elemental palladium by the reaction,370 RC3H4X + RhXL3 = RhX,(x-C,H,R)L2 + L 361 C.G. Hull and M. H. B. Stiddard J . Organometallic Chem. 1967,9 519. 362 M. L. H. Green A. G. Massey J. T. Moelwyn-Hughes and P. L. I. Nagy J . Organometallic 363 F. A. Hartman P. J. Pollick R. L. Downs and A. Wojcicki J . Amer. Chem. SOC. 1967,89,2493. 364 C. A. Reilly and H. Thyref J . Amer. Chem SOC. 1967,89 5144. 365 H. C. Volger and K. Vrieze J . Organometallic Chem. 1967,9 527. M. McPartlin and R. Mason Chem Comm. 1967 16. 367 J. M. Rowe and D. A. White J . Chem SOC. (A) 1967 1451. 368 A. D. Ketley L. P. Fisher A. J. Berlin C. R. Morgan E. H. Gorman and T. R. Steadman, 369 D. Morelli R. Ugo F. Conti and M. Donati Chem Comm. 1967 801. 370 S. P. Gubin A. Z. Rubezhov L. I. Denisovitch and A.N. Nesmeyanov Isvest. Akad. Nauk. Chem. 1967,8 51 1. Inorg. Chem. 1967,6657. S.S.S.R. Ser. khim. 1966 1680 350 J. A. McGinnety and M. J. Mays [PdCl(C3H5)I2 + 2Hg + 2Pd + 2HgCl(C3H5) Elemental palladium is also formed when carbon monoxide is bubbled through a solution of acetylacetonato-x-aIlylpalladium(~I) ; the ligands on palladium couple to form allyla~etylacetone.~~ The complex equilibria set up when the compounds [PdX(allyl)] (X = halide) are treated with a ligand have been thoroughly in~estigated.~” The structure of di-p-chloro-bis-(x-1,3-dimethylallyl)dipalladium(11) has been determined by X-ray crystal-10graphy;’~~ the allyl groups are asymmetrically x-bonded and the methyl carbon atoms are not coplanar with the allyl plane. The bridge is not planar and there is an angle of 150” between the co-ordination planes of the two palladium atoms.The facile abstraction of PdCl from the n-ally1 compounds of general formula [(C,H2,- 1)2Pd3C14] suggests that the three palladium atoms may be arranged as a metal cluster,373 rather than a linear array joined by halogen bridges as previously suggested.374 Iodoallyltriphenylphosphinenickel(rr) reacts reversibly with carbon mon-oxide to form a 1 1 adduct. The adduct is also formed by the reaction of tri-carbonyltriphenylphosphinenickel(o) with allyl iodide. The adduct reacts with acetylene and carbon monoxide in methanol solution to form methyl cis-hexa-2,5-dienoate tricarbonyltriphenylphosphinenickel(o) and hydrogen iodide.375 Bromo-x-allylnickel(I1) can be used as a reagent to replace halogen in alkyl aryl or vinyl halides by CH,:CH*CH,-; when substituted allyl compounds are used this is a useful route in preparative organic chemistry.376 Cis- and trans-isomers of bis-x-ally1 nickel compounds have been isolated.37 Tris-x-allyliridium(~~r) is formed by the reaction of allylmagnesium chloride with tris(acetylacetonato)iridium(nr) or iridium trichloride in tetrahydro-f~ran.,~’ Triallylboron compounds react with dimethylzinc to form diallyl-zinc compounds.379 n-Complexes of Straight-chain Mono- and Po1yenes.-The structure of bis(triphenylphosphine)(ethylene)nickel has been determined by X-ray crystal-lography the carbon atoms of ethylene are essentially equidistant from nickel.An ionic product isolated from the reaction of tetrafluoroethylene with trans-hydridochlorobis(triethy1phosphine)platinum under forcing conditions was incorrectly formulated7 as the five co-ordinate n-complex PtHCI(PEt,) -C2F ; an X-ray crystallographic structure determinati~n~~ showed the compound to be [trans-PtCl(CO)(PEt,),+ J[BF,-].Carbonyl complexes were also isolated from the reaction of tetrafluoroethylene with the 371 Y . Takahashi S. Sakai and Y . Ishii Chem. Comm. 1967 1092. 372 G. R. Davies R. H. B. Mais S. O’Brien and P. G. Owsten Chem. Comm. 1967 1151. 373 M. Donati and F. Conti Inorg. Nuclear Chem. Letters 1966,2 343. 374 I. I. Moiseev M. N. Vargaftik and J. K. Syrkin Isvest. Akad. Nauk. S.S.S.R. Ser. khim. 1964, 375 F. Guerrieri and G. P. Chiusoli Chem Comm. 1967,781. 376 E. J. Corey and M. F. Semmelhack J .A m . Chem SOC. 1967,89,2755. ”’ H. Bonnemann B. Bogdanovik and G. Wilke Angew. Chem. Internat. Edn. 1967,6 804. 3’8 P. Chini and S. Martinengo Inorg. Chem. 1967,6837. 379 K. H. Thiele G. Engelhardt and J. Kohler J . Organometallic Chem. 1967 9 385. 300 C. D. Cook C. H. Koo S. C. Nyburg and M. T. Shiomi Chem. Comm 1967,426. 775 Transition-M eta1 Carbonyls and Organometallic Complexes 35 1 rhodium complexes Rh2Cl,L4 where L is a tertiary p h ~ s p h i n e ~ ~ and it seems likely that co-ordinated tetrafluoroethylene can undergo some unusual reactions. The stabilities of a number of olefin complexes of rhodium(1) have been compared ;3 alkyl-substituted olefins form weak adducts whereas fluoro-olefins form strong adducts. Sulphur dioxide reacts with n-cyclo-pentadienylbis-n-ethylenerhodium(1) by an electrophilic mechanism382 and the product Rh(x-CSHS)(n-C2H4)(SO2) exhibits free rotation of the ethylene ligand at room temperature; this rotation becomes hindered only upon cooling below - 10°C.In the hydrogenation of olefins catalysed by chloro-tris(triphenylphosphine)rhodium(I) the transition state involves the co-ordination of the olefin to a hydridorhodium complex; the kinetic and thermo-dynamic changes incurred by using different olefins has been examined104 and steric effects are of primary importance. The reaction of dienes with ethanolic rhodium trichloride gives products formed by the addition of ethanol to the diene.383 The optically active bicyclic olefin p-pinene forms a complex with a solution of Na,[PtCl,] and the circular dichroism of the resulting solution has been measured.384 The i.r.spectra of substituted pyridine complexes of dichloro-cis-2-buteneplatinum(rr) indicate that the n* orbitals of co-ordinated pyridine can compete with the olefin n* orbital for metal d - e l e ~ t r o n s . ~ ~ ~ A normal-co-ordinate analysis of the i.r. spectrum of Zeise's salt has been reported.386 The n.m.r. spectra of several x-ethyleneplatinum complexes have been re-ported.387 Zeise's salt reacts with bipyridyl to liberate ethylene ; this reaction has been studied kineti~ally."~ The mechanism is thought to involve bi-molecular attack by bi-pyridyl displacement of two chloride ions to form [cis-PtC1(C2H4) bipy '1 followed by replacement of ethylene by one chloride ion to form [cis-PtC1 bipy] which is isolated.x-Complexes of general formula [Pt(olefin)(Ph,P),] have been isolated when the olefin is substituted by electron-withdrawing groups.389 Straight-chain olefins react directly with palladium dichloride to form n-complexes of general formula [PdCl,(~lefin)].~~~ The structure of C1-butadiene-bis(x-cyclopentadienyldicarbonylmanganese) has been determined by X-ray crystallography;3g' butadiene is in the trans-configuration the two olefinic double-bonds co-ordinate separately to different manganese atoms and the C(2)-C(3) distance in butadiene is not significantly '" R. Cramer J . Amer. Chem. SOC. 1967,89,4621. '13' R. Cramer J . Amer. Chem. SOC. 1967,89 5377. '13' K. C. Dewhirst J. Org. Chem. 1967 32 1297. 384 E. Premuzic and A.1. Scott Chem. Comm. 1967 1078. 38s P. Schmidt and M. Orchin Znorg. Chem. 1967,6 1260. 386 J. Pradilla-Sorzano and J. P. Fackler jun. J. Mol. Spectroscopy 1967,22 80. '13'~ A. R. Brause F. Kaplan and M. Orchin J . Amer. Chem. Soc. 1967,89 2661. 387c B. F. G. Johnson C. Holloway G. Hulley and J. Lewis Chem. Comm. 1967 1143. P. Uguagliati U. Belluco U. Croatto and R. Pietropaolo J . Amer. Chem. SOC. 1967,89 1336. 389 S. Cenini R. Ugo F. Bonati and G. La Monica Znorg. Nuclear Chem. Letters 1967 3 191. G. F. Pregaglia M. Donati and F. Conti Chem and Znd. 1966 1923. 391 M. Ziegler Z. anorg. Chem. 1967,355 12. H. P. Fritz and D. Sellmann Z . Naturj-orsch. 1967 22b 610. 352 J. A. McGinnety and M . J . Mays different from that expected for a single bond.392 A similar configuration for butadiene has been proposed for potassium p-1,3-butadiene-bis(trichloro-platinate) on the basis of the i.r.spectrum.392 cis-Dichloro-1,s-hexadienepal-ladium(I1) has been prepared ; an X-ray structure determination shows the compound to be monomeric with both olefinic bonds co-ordinated to the metal and in a plane perpendicular to the plane of co-ordination around palladium.393 Butadiene reacts with the sodium salt or hydride of tricarbonyl-nitrosyliron to form x-ally1 complexes which react with triphenylphosphine either with loss of carbon monoxide or to form diene complexes.394 Bi-nuclear-olefin-gold complexes have been prepared in which the olefin can be either linear or cyclic.395 n-Complexes having Another Donor Site.-Unsaturated amines e.g.allylamine but-3-enylamine and the corresponding unsaturated alcohols form complexes with platinum in which the olefin is co-ordinated to platinum; the thermodynamics of the formation equilibria of these complexes have been thoroughly in~estigated~’~ and comparisons made with similar silver com-ple~es.~” Complexes of copper(^)^^^ and p a l l a d i ~ m ( n ) ~ ~ ~ with unsaturated alcohols have also been reported in CuCl(CH2 CH CH OH) there is co-ordination from both the olefinic bond and the hydroxy-oxygen atom. cis-l,2-Bis(diphenylphosphino)ethylene forms the complexes [M(Ph2P*CH:CH-PPh2)22+] (M = Co or Ni) and co-ordination is ex-clusively through the phosphorus atoms.400 Iron and cobalt react with ketenimines R2C C NR’ to form x-adducts, e.g.dodecacarbonyltri-iron reacts with N-methyldiphenylketenimine to form Fe,(CO),(Ph,C:C NMe) in which both the carbon-carbon and carbon-nitrogen double bonds participate in co-~rdination.~~ ’ The reactions of iron carbonyls with analogues of 1,3-dienes have also been examined; the analogues used were unsaturated imines RCH CH CH NR di-imines RN CH CH NR and azines RCH N ON CHR. The unsaturated imine complexes are analogous to x-1,3-diene complexes whereas co-ordination in the di-imine complexes is through the nitrogen lone-pairs ; no azine complexes were isolated.204 Alkylvinylketone complexes of molybdenum402 and iron403 have been 392 M. J. Grogan and K. Nakamoto Inorg. Chin Acta 1967,1,228. 393 I. A. Zakharova G. A. Kukina T. S. Kuli-Zade I. I. Moiseev G.Yu Pek and M A. Porai-394 F. M. Chaudhari G. R. Knox and P. L. Pauson J . Chem. SOC. (C) 1967,2255. 395 R. Huttel H. Reinheimer and K. Nowak Tetrahedron Letters 1967 1019. 396 R. G. Denning F. R. Hartley and L. M. Venanzi J . Chem. SOC. (A) 1967,324; R. G. Denning, F. R. Hartley and L. M. Venanzi ibid. p. 328; F. R. Hartley and L. M. Venanzi ibid. p. 330; R. G. Denning and L. M. Venanzi ibid. p. 336. Koshits Zhur. neorg. Khim. 1966 11 2543. 397 F. R. Hartley and L. M. Venanzi J . Chem. SOC. (A) 1967 333. 398 T. Ogura N. Furuno and S. Kawaguchi &U. Chem. SOC. Japan 1967,40 1171. 399 A. V. Babaeva T. I. Beresneva and Yu Ya. Kharitonov Doklady Akad. Nauk. S.S.S.R. 1967, 175 591. 400 H. N. Ramaswamy H. B. Jonassen and A. M. Aguiar Znorg. Chirn. Acta. 1967,1 141.401 S. Otsuka A. Nakamura and T. Yoshida J . Organometallic Chem. 1967,7 339. *02 R. B. King J. Organornetallic Chem. 1967,8 139. 403 A. N. Nesmeyanov K. Ahmed L. V. Rybin M. I. Rybinskaya and Yu. A. Ustynyuk J . Organo-metallic Chem. 1967 10 121 Transition-M eta1 Carbonyls and Organometallic Complexes 353 isolated and characterised. In the molybdenum compound, Mo(MeC0- CH CH2)3 both the carbon-carbon and carbon-oxygen double bonds participate in x-bonding whereas in the iron compound, Fe(CO),(MeCO CH CHCl) only the carbon-carbon double bond partici-pates. Acrylonitrile CH2 CH CN reacts with ammonium hexachloro-platinate upon irradiation to form dichlorobisacrylonitrileplatinum(n) in which there is co-ordination by the olefinic double bond.,', The reactions of carbon disulphide with a number of transition-metal complexes have been examined.Carbon disulphide reacts with aqueous potassium pentacyanocobaltate(r~) to form K,[Co(CN) SCS- Co(CN),] in which carbon disulphide acts as a bridging group each sulphur atom bonding to a cobalt atom.299 In a much more complete study,405 the reactions of carbon disulphide with a number of low-valent complexes of Group VIII metals have been shown to yield products in which one carbon-sulphur double bond x-bonds to the metal. For example tris(triphenylphosphine)platinum(o) reacts with carbon disulphide to form orange needles of Pt(CS2)(Ph3P) ; the structures of this compound406 and of the palladium analogue407 have been determined by X-ray crystallography. In both compounds the inner co-ordination sphere around the metal is almost planar; one sulphur atom and the carbon atom of carbon disulphide are approximately equidistant from the metal and the carbon disulphide moiety is bent.The geometry of carbon disulphide in these complexes is remarkably similar to that in the lowest excited state (3A2) of free carbon disulphide and the electron distribution may be similar. Acetylene Complexes.-Octacarbonyldicobalt reacts with monosubsti tu ted acetylenes RC i CH (R = CF3408 or C6FS4O9) to form compounds of general formula CO~(CO)~(RC~ CH); these compounds are thought to have two Co(CO) fragments joined by a metal-metal bond with the acetylene above and normal to this bond axis. Pentacarbonyliron also reacts with these acetyl-enes ; the products are the disubstituted cyclopentadieneone complexes, Fe(CO),(R,C,H,O).Octacarbonyldicobaltmercury reacts with acetylene and diacetylene to form a number of x-complexes.410 The displacement of acetylene from Co,(CO),(RCi CR) by other acetylenes has been studied ;41 the stability of the complex increases as the electronegativity of the substituents on acetylene is increased and the most stable adducts are also symmetrical. The kinetics of the reaction of octacarbonyldicobalt with substituted phenyl-and diphenyl-acetylenes has been studied.,' 404 Yu. N. Kukushkin A. A. Lipovski . Yu. E. Vyaz'menskii Zhur. neorg. Khim. 1967,12 1090. 405 M. C. Baird and G. Wilkinson J . Chem. SOC. ( A ) 1967,865. *06 M. Baird G. Hartwell jun. R. Mason A. I. M. Rae and G. Wilkinson Chem.Comm. 1967,92. *07 T. Kashiwagi N. Yasuoka T. Ueki and N. Kasai and M. Kakudo Bull. Chem. SOC. Japan, *08 R. S. Dickson and D. B. W. Yawney Austral. J . chem. 1967,20 77. *09 R S. Dickson and D. B. W. Yayney Inorg. Nuclear Chem. Letters 1967,3,2W. * I 0 G. Peyronel A. Ragni and E. F. Trogu. Gazzetta 1967.97 1327. 412 N. Almasi and M. Domokos Stud. Univ. Bobes-Bolyai Ser. Chem. 1966 101. 1967,8 1998. G. Cetini 0. Gambino R. Rosetti and E. Sappa J . Organornertalic Chem. 1967,8 149 354 J . A . McGinnety and M . J . Mays Acetylenes with electron-withdrawing substituents form stable 1 1 adducts with chlorocarbonylbis(tripheny1phosphine)-iridium(1) and -rhodium(~).~'~ The structure of dichloro(di-t-butylacetyleneXp-to1udidine)platinum has been determined by X-ray crystallography ;414 the co-ordination around platinum is square-planar when the acetylene is considered a monodentate ligand and the two acetylenic carbon atoms are equidistant from platinum and lie on a line perpendicular to the co-ordination plane.The structure of (diphenylacetyl-ene)bis(triphenylphosphine)platinum has been determined by X-ray crystal-lography ;41 s the two acetylenic carbon atoms are equidistant from platinum and lie on a line inclined at 14" to the plane defined by the platinum and two phosphorus atoms. In both of these acetylene complexes of platinum the 'acetylenic' carbon-carbon interatomic distance is lengthened by about 01 A. compared with free acetylene and the substituents on the acetylene are bent back by about 40". Cyclobutadiene Complexes.-Ring systems C,R n = 3-8) form complexes with transition metals in which the substituent R is bent out of the plane of the ring away from the metal; this can be explained in terms of the non-orthogonality of the ring framework and the orbitals of the metal atom.416 An interesting new synthesis of tricarbonylcyclobutadieneiron has been reported.Photolysis of a-pyrone followed by addition of pentacarbonyliron and further irradiation yields tricarbonylcyclobutadieneiron plus tricarbonyl-a-pyr~neiron.~" Photolysis of a-pyrone is known to form photo-a-pyrone an isomer which has a 'Dewar'-type structure; the preparation of the cyclo-butadiene complex is thought to proceed via a complex of this isomer followed by loss of carbon dioxide. A widely applicable method of preparation for cyclobutadiene complexes is to treat the sodium derivative of a transition-metal carbonyl with dichloro-cyclobutene.In this way complexes of iron ruthenium molybdenum and tungsten have been prepared.418 Tetraphenylcyclobutadiene complexes of nickel4' and cobalt420 have been prepared by ligand-exchange reactions using the readily available complexes [PdX,(Ph,C,)] (X = halogen). Tetra-methylcyclobutadiene complexes of iron4,' and cobalt4, can also be prepared by ligand exchange using dichloro(tetramethylcyclobutadiene)nickel(rI). Cyclopentadiene Complexes.-Biscyclopentadienyltitanium(I1) was origin-ally thought to have a monomeric ferrocene-type structure but molecular weight measurements show the compound is dimeric in solution.A dimeric structure is also consistent with the slow reaction of this compound with 413 J. P. Collman and J. W. Kang J . Amer. Chem. SOC. 1967,89,844. 414 G. R. Davies W. Hewertson R. H. B. Mais and P. G. Owsten Chem. Comm. 1967,423. 415 J. 0. Glanville J. M. Stewart and S. 0. Grim J . Organometallic Chem. 1967,7 P. 10. 416 S. F. A. Kettle Inorg. Chim. Acta 1967 1,303. 417 M. Rosenblum and C. Gatsonis J . Amer. Chem. SOC. 1967,89,5074. 418 R. G. Amiet P. C. Reeves and R. Pettit Chem. Comm. 1967,1208. 419 D. F. Pollock and P. M. Maitlis Canad. J . Chem. 1966,44,2673. 420 A. Efraty and P. M. Maitlis J . Amer. Chem. SOC. 1967,89 3744. 421 R. Bruce K. Moseley and P. M. Maitlis Canad. J . Chem. 1967 45 2011. 422 R. Bruce and P. M. Maitlis Canad. J . Chem. 1967,45,2017 Transition-M eta1 Carbonyls and Organometallic Complexes 355 carbon monoxide to form monomeric dicarbonylbiscyclopentadienyltitani-urn(@; furthermore the reaction with molten 2,2’-bipyridyl yields a polymeric compound of composition [Ti(C,H5)2 bipy].The monomeric compound of this composition is formed by the reduction of dichlorobiscyclopentadienyl-titanium(1v) with 2,2’-bipyridyldilithi~m~~~ or by the reaction of dicarbonyl-biscyclopentadienyltitanium(I1) with 2,2’-bip~ridy1.~~~ The preparation and reactions of biscyclopentadienyltitanium(~~) and cyclopentadienylphenyl-titanium have been further Dichlorobiscyclopentadienylzirconi-um(1v) reacts with cyclopentadienylsodium to form tetracyclopentadienyl-zirconium an air-stable crystalline solid with all protons apparently equiva-lent.426 Dichlorobiscyclopentadienylzirconium(1v) reacts with sodium naphthide liberating naphthalene and forming biscyclopentadienylzirconium-(10 a pyrophoric purple-black crystalline solid.427 Hafnium tetrachloride reacts with cyclopentadienylsodium to form tetracyclopentadienylhafnium(1v) ; the reactions of this compound are reported.428 Reduction of substituted fulvene yields intermediates used to prepare mono- and di-alkyl-substituted derivatives of dichlorobiscyclopentadienyltitanium(I1).Bis(cyclopentadienyl)diphenoxotitanium(Iv) Ti(OPh)2(lt-C5H5)2 is formed by the reaction of phenol with dichlorobiscyclopentadienyltitanium(1v) in the presence of sodamide ;429 another paper430 reported failure to synthesise this compound and confirmed an earlier report of the ready synthesis of the cor-responding sulphur compounds Ti(SR)2(~-CSH5)2.Dithiocyanatobiscyclo-pentadienyltitanium(w) is formed by the reaction of dichlorobiscyclopenta-dienyltitanium(w) with potassium thiocyanate and opposing conclusions have been drawn about whether the thiocyanato-ligands are S-430 or N-bonded.43 Cyanato- and thiocyanato-complexes of general formula MX2(lt-C,H,)2 (M = Ti Zr or Hf; X = SCN,OCN) have been reported.431- 432 Chelate complexes of titanium(1v) have been isolated and characterised ;433 these have the general formula [Ti(lt-CSH5)2L+] where L is the conjugate base of a P-diketone and they were isolated as salts of large anions e.g. PF6-. A number of monocyclopentadienyl derivatives of zirconium(1v) containing three chelating groups have been ~ynthesised.~~~ The chelating agents are the conjugate bases of either 8-hydroxyquinoline or acetylacetone.If all three 423 F. Calderazzo J. J. Salzmann and P. Mosimann Inorg. Chim. Acta 1967,1 65. 424 E. 0. Fischer and R. Amtmann J . Organometallic Chem. 1967,9 P. 15. 42s G. A. Rasuvaev K. N. Latyaeva L. I. Vyshinskaya and G. A. Kilyakova Zhur. obshch. Khim., 426 E. M. Brainina and G. G. Dvoryantseva Izvest. Akad. Nauk. S.S.S.R. Ser. khim. 1967,442. 427 G. W. Watt and F. 0. Drummon4jun J . Amer. Chem SOC. 1966,88,5926. 428 M. Kh. Minacheva E. M. Brainina and R. Kh. Freidlina Doklady Akad. Nauk. S.S.S.R. 1967, 429 K. AndrZi 2. Chem. 1967,7 318. 430 S. A. Giddings Znorg. Chem. 1967,6 849. *” E. Samuel h l l . SOC. chim.France 1966 3548. OJ3 G. Doyle and R. S. Tobias Inorg. Chem. 1967 6 1111. 434 E. M. Brainina E. I. Mortikova L. A. Petrashkevich and R. Kh. Freidlina Doklady Chem, 1966,36,1491. 173 581. R. Coutts and P. C. Wailes Austral. J . Chem. 1966 19 2069. 1966,169,681 356 J . A. McGinnety and M . J . Mays chelating groups are bidentate zirconium achieves the electronic configuration of xenon and is formally nine-co-ordinate A spiroheterocyclic compound containing zirconium(1v) has been prepared by the reaction of dichloro-biscyclopentadienylzirconium(1v) with tetrakis-[(potassiumphenylphosphino)-meth~llrnethane.~~ Chlorobiscyclopentadienyltitanium(m) is a 1 1 electrolyte in oxygen-free aqueous solution ; addition of sodium pseudo-halides causes precipitation of pseudo-halide derivatives of titanium(~rr)?~ such as [Ti(CN)(n-C H ,),I3, [T~(SCN)(X-C,H,)~]~ and Ti(NCO)(n-C,H,),.Addition of sodium salts of organic acids to aqueous chlorobiscyclopentadienyltitanium(n1) yields mono-meric carboxylato- derivative^.^^ The monomeric derivatives of titanium(rI1) have magnetic susceptibilities corresponding to one unpaired electron, whereas the magnetic susceptibilities of the trimeric compounds are lowered by spin-spin interaction. Dihalogenobiscyclopentadienyltitanium(1v) species are thought to be dimeric in acetone solution and some kinetic data have been reinterpreted on this basis.438 The crystal structure of tetracarbonylcyclopentadienylvanadium(1) has been reported.439 For the stereochemical description only the cyclopentadienyl ring is considered monodentate and the inner co-ordination sphere is thus a distorted square pyramid with the carbonyl groups bent away from the ring; the ring is apparently typically n-bonded but is disordered in the crystal and thus the ring bond-lengths are not known accurately.Several cyclopentadienyl complexes have been examined theoretically using semi-empirical methods.440 Halide and chalcogenide derivatives of general formula MX,(x-C,H,), [M = Mo or W; X = halogen SAr or OAr (Ar = aryl)] have been pre-pared.441 The reactions of nucleophilic reagents such as phenyl-lithium with cyclopentadienylmetal carbonyls have been examined ;442 four different reac-tions can occur and the course of the reaction depends primarily upon the met a1 . Several pen tame t h ylc yclo pen tadien yl derivatives of transition metals have been preparedZBZ and the relatively small differences between these and the corresponding unsubstituted cyclopentadienyl complexes are discussed.The electron paramagnetic resonance spectra of M(rC5H5), (M = Rh or Ir) have been measured at the temperature of liquid nitrogen.443 The structure of biscyclopentadienylnickel(I1) has been determined in the gas phase ;444 the metal-carbon distances are all 2*19+ 0.01 A and the C-H bonds are bent 435 J. Ellermann and F. PBrsh Angew. Chem Znternat. Edn. 1967,6 355. 436 R. S. P. Coutts and P. C. Wailes Znorg. Nuclear Chem Letters 1967,3 1. 437 R. S. P. Coutts and P. C. Wailes Austral. J . Chem 1967,20 1579. 438 A. Jensen and E. Jsrgensen J . Organometallic Chem 1967,7,528.439 J. B. Wilford A. Whitla and H. M. Powell J . Organometallic Chem. 1967,8 495. **O M. Randit N. Trinajstik J . Chem. Phys. 1967,46 1469; A. T. Armstrong D. G. Carroll and S. P. McGlynn J . Chem Phys. 1967,47 1104. 441 M. L. H. Green and W. E. Lindsell J . Chem SOC. (A) 1967,1455; R. L. Cooper and M. L. H. Green ibid. p. 1155; M. L. H. Green and W. E. Lindsell ibid. p. 686. **' P. M. Treichel and R L. Shubkin Znorg. Chem. 1967,6 1328. u3 H. J. Keller and H. Wawcrsik J . Organometallic Chem 1967,8 185. 4~ I. A. Ronova and N. V. Alekseev Zhur. strukt. Khim 1966,7,886 Transition-M eta1 Carbonyls and Organometallic Complexes 357 out of the plane of the rings away from the metal atom by 6”. Biscyclopenta-dienylnickel(r~) reacts with triphenylphosphonium halides to form halogeno-c yclo pen t adien y 1 trip hen y 1 p ho sp hinenickel( II) Nix( R-C H )(P h P) where X = C1 Br I.445 Biscyclopentadienylcobalt(I1) is oxidised by pentacarbonyliron(0) to form [C.(R-C~H,)~]~[F~,(CO)~~] ; the cation and anion were isolated separately as the tetraphenylborate and tetramethylammonium salts respectively.446 Iditrile derivatives of biscyclopentadienylruthenium(n) tricarbonylcyclopenta-dienylmanganese and tricarbonylcyclopentadienylrhenium have been pre-pared.447 The Mossbauer spectrum of ‘ferricinium ferrichloride’ shows a single maximum at room temperature.Whilst this would be characteristic of the symmetrical structure di-~-chloro-bis[chloro(cyclopentadienyl)iron(n~)] in-direct methods show that the compound is more likely to be the tetrachloro-ferrate salt of the ferricinium cation.448 Ferrocene reacts with some strong protic acids to form deeply-coloured paramagnetic compounds that are strong binary electrolyte^.^^' Electron transfer has occurred and the products are probably ferricinium salts of anions which are proton acids with one electron in an antibonding molecular orbital.F~(R-C,H~)~ + HBF = [Fe(C,H,);][HBF,-] Much organic chemistry involving the ferrocene nucleus has been e~amined.~” The configuration of some optically active ferrocenes has been determined by X-ray crystall~graphy~~ and optical rotatory The dimeric compound (F~(R-C,H,)[P(OP~),]~)~ reacts with iodine to form two isomeric compounds of composition F~I(R-C,H,)[P(OP~),]~. One isomer has a singlet cyclopentadienyl ‘H n.m.r.absorption and the other has two doublets; the nature of the isomerism is not clear.453 o-Bonded cyclo-pentadienyl compounds often undergo rapid exchange of the metal-carbon bond with consequent equilibration of the protons; this occurs in the case of ‘” M. van den Akker and F. Jellinek Rec. Trav. chim. 1967,86,897. 446 G. A. Rasuvaev G. G. Petukhov V. 1. Ermolaev and V. P. Beketov Zhur. obshch. Khim. 1967, 37 672. 447 A. N. Nesmeyanov N. E. Kolobova K. N. Anisimov and Yu. V. Makarov Zzvest. Akad. Nauk. S.S.S.R. Ser. khim. 1967 953; A. N. Nesmeyanov A. A. Lubovich. L. P. Yur’eva S. P. Gubin and E. G. Perevalova lzvest. A M . Nauk. S.S.S.R. Ser. khim. 1967,935. R. A. Stukan and L. P. Yur’eva Doklady Chem. 1966,167,448. 449 M. M. Aly D.V. Banthorpe R. Bramley R. E. Cooper D. W. Jopling. J. Upadhyay A. Wasser-mann and P. R. Wooliams Monatsh.,’1967,98 887. M. Hadlington B. W. Rockett and A. Nelhans J . Chem. SOC. (C) 1967 1436; G. R. Knox, I. G. Morrison and P. L. Pauson ibid. p. 1842; W. E. Watts Organometallic Chem Rev. 1967 2, 231; T. H. Barr and W. E. Watts J . Organometallic Chem. 1967,9 P3; W. Reeve and E. F. Group, jun. J . Org. Chem. 1967 32 122; T. P. Vishnyakova N. Ya. Mar’yashkin and M. E. Elyashberg, Zhur. org. Khim. 1967,3,947; A. N. Nesmeyanov E. G. Perevalova L. I. Leont’eva and 0. F. Filippov, Zzvest Akad. Nawk. S.S.S.R. Ser. khim 1967,464. ’” 0. L. Carter A. T. McPhail and G. A. Sim J . Chem. SOC. (A) 1967 365. ’” G. Haller and K. Schlbgl Monutsh. 1967 % 603. 453 A. N. Nesmeyanov and Yu.A. Chapovskii Zzvest. Akad. Nauk. S.S.S.R Srr khim . 1967 223 358 the recently isolated cyclopentadienyl complexes of gold(1),4’~ which must be assumed to be a-bonded from electronic considerations. Arene Complexes.-Vanadium tetrachloride reacts with phenyl magnesium bromide to form the sandwich compounds bis-n-benzenevanadium and bis-n-diphenylvanadium ;45 ’ the reaction proceeds via a o-phenylvanadium(I1) complex which disproportionates to form diphenyl. Vanadium tetrachloride reacts with phenyl-lithium to form bis-phenylvanadi~m.~’~ Salts of vanadium(Irr) chromium(nI) and nickel(r1) are reduced by lithium naphthide in solution. The products were not isolated but electron paramagnetic reson-ance shows that a bis-n-arene complex of vanadium(o) was present in the vanadium mixture and that excess naphthide results in further reduction to vanadium( - I) and vanadium( - II) species ; hydrogen transfer from the arene to vanadium and the presence of a vanadium hydrido-species was deduced from hydrolysis and deuteriolysis experiment^.^' o-Bonded arylchromium compounds usually undergo rearrangement to n-arenechromium compounds.The o-bonded triphenylchromium(r1r) can be isolated as the tris(tetrahydrof~ranate),4’~ but upon loss of tetrahydrofuran (THF) a rearrangement occurs and the products are bis-n-diphenylchromi-um(o) benzene diphenyl and a black material of composition CrPh(THF),. ; hydrolysis of this black material yields (n-benzene)(n-diphenyl)chromium(o), bis-(a-benzene)chromium(o) benzene hydrogen and chromium(rI1) hydroxide.The yield of each of these products has been determined quantitatively4” and a mechanism for the rearrangement has been proposed. Further information about the mechanism has been gained by a study of the variation in yield of bis-(n-arene)chromium(o) complexes with the aryl The a-bonded arylchromium(r1) compounds are even more labile and cannot be isolated unless rearrangement to n-complexes is impossible as in the formation of e.g. o-mesityl and o-naphthyl complexes of chromium(I1) which have been isolated,461 thus supporting the suggested mechanism. The preparation and properties of o-bonded alkyl- and aryl-chromium compounds has been reviewed.462 Iodobisdiphenylchromium(1) can be reduced by sodium borohydride to bisdiphenylchromium(0) ; the reaction was studied polarographically and only proceeds in the presence of trace amount of trisbipyridylcobalt(r1) di-chloride which acts catalytically via electron transfer by the redox system C O ~ * - C O * .~ ~ ~ n-Arenetricarbonylchromium(o) compounds should be optically J . A. M cGinnety and M . J . Mays 454 R. Hiittel Angew. Chem. Internat. Edn. 1967,6 862. ”’ E. Kurras Z . anorg. Chem. 1967,351 268. 456 G. A. Razuvaev V. N. Latyaeva B. G. Zateev and G. A. Kilyakova Doklady. Akad. Nauk. 45’ G. Henrici-Olivt and S. OlivQ J . Organometallic Chem. 1967,9 325. 458 F. Hein and K. Schiedeknecht Z . anorg. Chem. 1967,352 138. 459 J. Hihle and G. Stolze J . Organometallic Chem. 1967,8 3 11. 460 M. Tsutsui and M. N. Levy 2. Naturforsch. 1966 21b 823. 461 G.Stolze and J. Hiihle J . Organometallic Chem. 1967,7 301. 463 A. Rusina H. P. Schroer and A. A. VIEek Z . anorg. Chem. 1967 351,275. S.S.S.R. 1967 172 1337. H. H. Zeiss and R. P. A. Sneeden Angew. Chem. Internat. Edn 1967 6,435 Transition-M eta1 Carbonyls and Organometallic Complexes 359 active when the arene group is disubstituted in the Q- or m-positions. Tricarbonyl-(lc-o-methoxybenzoic acid(chromium(o) has been resolved using the brucine salt. 464 Condensed aromatic compounds have more than one site with which to interact with metal atoms to form x-arene complexes. x-Com-plexes of tricarbonylchromium(o) with naphthalene substituted naphtha-lene~:~’ anthracene and other condensed aromatic compounds466 have been prepared and the site of interaction determined by ‘H n.m.r.spectroscopy. Compounds of general type x-arenetricarbonylchromium(o) form adducts with 1,3,5-trinitrobenzene which exhibit a new charge-transfer band in the visible region of the spectrum from which the ionisation potentials were calculated and found to vary in the same sense as both the ionisation potential of the free arene and the frequency of the symmetric (A,) carbonyl stretching mode and in the opposite sense to the dipole moment of the Cr(CO),(x-arene).467 Phosphine ligands L stereospecifically displace the arene group from Mo(CO),(arene) to form cis-Mo(CO),L,. Studies using trimethylphosphite as L show the reaction is first order in both reactants:68 in agreement with earlier work using other phosphine l i g a n d ~ . ~ ~ ’ The initial and rate-determining, step is formation of Mo(CO),L(lc-arene) but the subsequent fast steps are not known unequivocally.It is most likely that another phosphine is added and then addition of the third phosphine causes expulsion of the arene. ‘Dewar’ hexamethylbenzene (hexamethylbicyclo[2,2,0]hexadiene) reacts with hydrated rhodium trichloride to form the n-arene complex [RhC1(C6Me6)],CI4 and reaction of this product with pyridine forms the mononuclear compound [RhCl py(C6Me6)]C12.470 Cyclo-octadiene Complexes.-Dichlorocyclo-octa- 1,5-dieneplatinum(11) reacts with excess isopropylmagnesium bromide to give cyclo-1,5-octadienebis-isopropylplatinum(I1) ; U.V. irradiation of the product in cyclooctadiene solution yields biscyclo-octa-1,5-dieneplatinum(o) a colourless diamagnetic solid which is more stable towards atmospheric oxidation than the correspond-ing nickel complex.471 The strength of cyclo-octa-1,5-diene as a ligand can be deduced from the following reactions.Biscyclo-octa- 1,5-diene complexes of copper@ can be prepared only in the absence of strong donors such as halide ions. Electrolytic reduction of copper@) salts in the presence of cyclo-octa-1,5-diene yields salts of biscyclo-octa-l,5-dienecopper(1) when the anions present are weak 464 R. Dabard and A. Meyer Compt. rend. 1967,264 C 903. 465 B. Deubzer H. P. Fritz C. G. Kreiter and K. Befele J . Organometallic Chem. 1967,7 289r 466 B. Deubzer E. 0. Fischer H. P. Fritz C. G. Kreiter N. Kriebitzsch H. D. Simmons jun., 467 G. Huttner and E. 0. Fischer J . Organometallic Chem.1967,8 299. 468 A. Pidcock J. D. Smith and B. W. Taylor J . Chem. SOC. (A) 1967,872. 469 F. Zingales A. Chiesa and F. Basolo J. Amer. Chem. SOC. 1966,88 2707. B. L. Booth R. N. Haszeldine and M. Hill Chem. Comm. 1967 1118. *’I1 J. Mfiller and P. Gliser Angew. Chem Internat. Edn. 1967 6 364. and B. R. Willeford jun. Chem. Ber. 1967 100 3084. M 360 donors such as p e r ~ h l o r a t e ~ ~ ~ or tetraflu~roborate.~~ Halogeno-It-allylnickel complexes react with cyclo-octa-1,5-diene to form NiX(C,H,,) (X = Cl or Br);474 the magnetic moment of these compounds was not measured but the presence of nickel(1) was confirmed by displacement of cyclo-octa-l,5diene with triphenylphosphine to form halogenotris(triphenylphosphine)nickel(I), the magnetic moment of which is 1.9 B.M.254 Cyclo-octa-1,Sdiene can be displaced from iridium(1) complexes by triphenyl ph~sphine,~~' e.g.from di-p-chloro-biscyclo-octa-1,5dienedi-iridium(1) to form chlorotris(tripheny1-phosphine)iridium(r) Tris(pentafluoropheny1)phosphine is displaced from di-p-chloro-tetra[tris(pentafluorophenyl)phosphine]dirhodium(~) to form di-p-chloro-biscyclo-octa-1,5dienedirhodium(1).~~~ Several phosphine ligands displace cyclo-octa-l,5diene and norbornadiene from CiS-M(CO)4(C8H12) (M = Cr Mo or W) with retention of configuration.477 Tert-butylisocyanate reacts with biscyclo-octa- 1,5dienenickel(o) to form terakis( t-but y1isocyanate)-nickel(o). 148 Cyclo-octa-l,5-dienecyclopentadienylcobalt(1) reacts with trityl fluoro-borate one hydrogen atom being abstracted from the eight-membered ring ; crimson crystals of the known compound [C~(I~-C~H,)(C,H~ ,)+][BF,-) can be isolated.Under similar conditions the rhodium analogue initially undergoes electrophilic substitution at the five-membered ring followed by hydrogen abstraction from the cyclo-octa-1,5-diene ring. Both cations add nucleophiles to form complexes in which the eight-membered ring is substi-t ~ t e d . ~ ~ Dichlorocyclo-octa-1,5-dienepalladium(11) reacts with silver acetate to form acetato-bridged complexes.479 The polymeric compounds [OsLCI,], where L = C6H6 or CSH12 are formed by the reduction of three- or four-valent osmium chlorides by alcohol in the presenke of cyclohexa-1,3-diene or cyclo-octa-1,5-diene re~pectively.~~' The temperature dependence of the 'H n.m.r.spectra of some cyclic polyolefin complexes of chromium molybdenum, and tungsten have been measured;481 the rate of equilibration of the protons varies greatly with the metal. The far-i.r. spectra of cyclo-octa-1,5-diene and cyclo-octatetraene complexes of platinum(I1) have been recorded and dis-cussed.482 Di-p-chloro-biscyclo-octa-1,5-dienedirhodium(1) reacts with iodine to form di-iodo-n-cyclopentadienylrhodium(~~~).~~~ This remarkable reaction proceeds rapidly at 0"c in ether solution precipitation of the product commencing J. A. M cGinnety and M. J. M uys 472 S. E. Manahan Znorg. Chem. 1966,5 2063. 473 S. E. Manahan Inorg. Nuclear Chem. Letters 1967 3 383. 474 L. Porri G. Vitulli and M. C. Gallazzi Angew Chem. Internat. Edn. 1967 6 452.475 M. A Bennett and D. L. Milner Chem. Comm. 1967 581. 476 R. D. W. Kemmitt D. I. Nicholls and R. D. Peacock Chem. Comm. 1967,599. 477 R. Mathieu and R. Poilblanc Compt. rend. 1967,264 C 1053. 478 J. Lewis and A. W. Parkins J . Chem. SOC. (A) 1967 1150. 479 C. B. Anderson and B. J. Burreson J . Organornetallic Chem 1967 7 181. 480 G. Winkhaus H. Singer and M. Kricke 2. Naturforsch. 1966,21b 1109. 481 R. B. King J . Organometallic Chem. 1967,8 129. *02 H. P. Fritz and D. Sellmann 2. Naturforsch. 1967 22b 20. 483 A. Kasahara T. Izumi and K. Tanaka &I!. Chem SOC. Japan 1967,40,699 Transition-M eta1 Carbonyls and Organometallic Complexes 36 1 immediately. The fate of the three-carbon fragment displaced from the ring was not determined. The black product a known compound was converted to cyclopentadienyldimethyl(triphenylphosphine)rhodium a yellow crystalline compound for which the n.m.r.spectrum is given. n-Complexes of Other Ring Systerns.-6,6'-Diphenylfulvene reacts with hexacarbonylchromium to form tricarbonyl(diphenylfulvene)chromium in which fulvene is x-bonded through its five-membered ring to chromium.484 Cationic complexes of cobalt rhodium and iridium containing n-bonded 6,6'-diphenylfulvene can be isolated as hexafluorophosphate salts by addition of ammonium hexafluorophosphate to the reaction mixture formed by 6,6'-diphenylfulvene the appropriate metal halide and isopropylmagnesium bromide.485 Hydropentalenylthallium can be used to prepare hydropentalenyl derivatives of iron rhodium and platinum.486 The structure of azulenepentacarbonyldi-iron has been determined by X-ray crystallography; the Fe(CO) and Fe(C0)2 moieties are joined by a metal-metal bond the five-membered ring of azulene behaves as a cyclo-pemtadienyl ligand and interacts symmetrically with the Fe(C0)2 group and three carbon atoms of the seven-membered ring form a n-allyl-metal inter-action with the Fe(CO) The structure of dimeric azulenetricarbonyl-methylmolybdenum [ M O M ~ ( C ~ ) ~ ( C ~ H ~ ) ] ~ has also been determined by X-ray crystallography ; co-ordination around molybdenum is similar to that in Mo(n-C,H,)Et(CO), the five-membered ring of azulene behaving like a cyclopentadienyl ligand and the two azulene rings are bonded together by a 4,4'-carbon-carbon single bond.488 The structure of Fe(CO),(C6F8) has been determined by X-ray crystallo-graphy; the ring is distinctly non-planar and is bound to iron by a n-bond from the only olefinic linkage in the ring and by two a-bonds from the carbon atoms adjacent to the olefinic linkage.489 Cyclohexen-2-one reacts with sodium tetrachloropalladate((rI) to form the dinuclear complex Pd2C12(C6H70)2, a centrosymmetric molecule with the chlorine atoms bridging the two palladium atoms and in which each ring is bound by a x-allylic interaction to a palladium atom.490 'Dewar ' hexamethylbenzene can displace nitriles from some com-plexes to form 'Dewar' hexamethylbenzene complexes in which both olefinic bonds of the ring system co-ordinate to a metal; complexes of palladium49' and chromium492 have been prepared in this way.The reaction of sodium methoxide with dichlorobicyclo[2,2,l]hepta-*'* R. L. Cooper E. 0. Fischer and W. Semmlinger J. Organometallic Chem 1967,9,333. *" E. 0. Fischer and B. J. Weimann J. Organometallic Chem. 1967,8 535. 486 T. J. Katz and J. J. Mrowca J. Amer. Chem. Soc. 1967,89 1105. M. R. Churchill Znorg. Chem. 1967,6190. P. H. Bird and M. R. Churchill Chem Comm. 1967,705. A. Kasahara K. Tanaka and K. Asamiya &11. Chem. SOC. Japan 1967,40,351. 489 M. R. Churchill and R. Mason Proc. Roy. SOC. 1967 (A) 301,433. 491 H. Dietl and P. M. Maitlis Chem Comm. 1967,759 ; E. E. van Tamelen and D. Carty J . Amm. 492 E. 0. Fischer C. G. Kreiter. and W. Bernguber Angew. Chem Internat. Edn. 1967,6 634. Chem. SOC. 1967,89,3922 362 J. A. McGinnety and M.J. Mays dienepalladium(i1) proceeds by nucleophilic attack of the methoxide ion on the olefinic group from the side opposite palladium followed by loss of a chloride ion from palladium ; the product is di-p-chloro-bis(6-methoxybicyclo-[2,2,1] hept-2-ene)dipalladium(rr) in which each ring is bound to one palladium atom by one a-bond as well as by donation from the one olefinic bond.493 Addition of methoxide anions to the tricarbonyltropyliumchromium cation also proceeds by attack from the side furthest from the metal and the product is the exo-isomer of tricarbonyl-(7-methoxycycloheptatriene)chromi~m.~~~ The corresponding endo-isomer has been prepared by the reaction of 7-methoxycycloheptatriene with hexacarbonylchromium.495 The reaction of trimethylphosphite with M(CO),(cycloheptatriene) (M = Cr Mo W) is first order in both reactants; the second-order rate constants vary in the order Cr < W < Mo which is the same as for the variation in metal-to-ring force constants in these compounds.496 Tricarbonylcyclo-heptadienyliron tetrafluoroborate reacts with potassium iodide carbon monoxide is displaced to form the covalent iodide FeI(C0)2(C7H9) ; using potassium cyanide instead of potassium iodide leads to the 5-exo-substituted cycloheptadiene compound Fe(CO),(C7H90Me).The covalent iodide can be converted to a dinuclear compound by reduction with sodium Cyclo-octatetraene reacts with dodecacarbonyltriruthenium and four products have been isolated from the reaction mixture RU(Co)3(C8&), spectrum of RU(CO)~(C~H~) has been recorded at temperatures down to -147"~; at low temperatures the ring is bound as a 1,3-diene in the chair configuration and as the temperature increases other tautomers become important.499 The structure of Ru3(CO),(C8H8) has been determined by X-ray crystall~graphy.~~~ The discussion of the structure in solution of Fe(CO),(C8H8) has been ~ontinued.~" The ring system in tricarbonylcyclo-octatetraeneiron can undergo addition reactions ; with substituted acety1enes5O2 1,4- and with l,l-dicyano-2,2-bis(tri-fluoromethy1)ethylene 1,2-addition .occurs.5o3 Biscyclo-octatetraeneiron is formed by the reduction of iron salts in the presence of excess cyclo-octatetra-ene ; it is a catalyst for the dimerisation of butadiene.504 Biscyclo-octatetraene-RU~(CO)~(C&J) RU2(CO)5(C8H,) and RU3(C0)4(C8H8)2.498 The 'H n.m.r.493 M. Green and R. I. Hancock J . Chem SOC. (A) 1967 2054. 494 P. L. Pauson G. H. Smith and J. H. Valentine J . Chem SOC. (C) 1967,1057. 495 P. L. Pauson G. H. Smith and J. H. Valentine J . Chem SOC. (C) 1967 1061. 496 A. Pidcock and B. W. Taylor J . Chem SOC. (A) 1967,877. 497 M. A. Hashmi J. D. Munro P. L. Pauson and J. M. Williamson J . Chem. SOC. (A) 1967,240. 498 F. A. Cotton A. Davison and A. Musco J . Amer. Chem SOC. 1967,89,6796. 499 M. I. Bruce M. Cooke M. Green and F. G. A. Stone Chem Comm. 1967,523; W. K. Bratton, F. A. Cotton A. Davison A. Musco and J. W. Faller Proc. Nut. Acud. Sci. U.S.A. 1967,58 1324. M. J. Bennett F. A. Cotton and P. Legzdins J . Amer. Chem. SOC. 1967,89,6797. F. A. L. Anet H. D. Kaesz. A. Maasbol and S. Winstein J . Amer. Chem. SOC. 1967 89,2489; U. Krfierke Angew. Chem Internat. Edn. 1967,6 79. M. Green and D. C. Wood Chem Comm. 1967 1062. A. Carbonaro A. Greco. and G. Dall'Asta Tetrahedron Letters 1967 2037. F. A. L. Anet ibid. p. 2491 Transition- Metal Carbonyls and Organometallic Complexes 363 nickel and other It-complexes of nickel can be similarly prepared.505 Cyclo-octene complexes of iridium(1) have been prepared ; one of these, [IrCl(CO)(C,H,,),], takes up reversibly two molar equivalents of ethylene.506 Pentafluorophenyl-lithium spontjmeously decomposes in benzene to form tetrailuorobenzobicyclo[2,2,2]-octatriene which forms A-complexes upon reaction with carbonyls of iron chromium molybdenum and tungsten.s07 'OS B. BogdanoviC M. Krilner and G. Wilkie Annulen 1967,699,l. B. L. Shaw and E. Sinsleton J. Chmr Soc. (A) 1967,1683. A. J. Todinson and A G. Massey J . Organometallic Chem. 1967,8,321

ISSN:0069-3022    

DOI:10.1039/GR9676400319

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

14. KINETICS AND MECHANISMS OF INORGANIC REACTIONS By J. Burgess (Chemistry Department University of Leicester) THIS Report is divided according to type of reaction. Redox reactions are considered first then substitution reactions followed by reactions of co-ordinated ligands and finally intramolecular processes. The section on substi-tution reactions is subdivided according to stereochemistry except for organo-metallic compounds whose reactions are discussed in a separate section. There is no division into transition-metal complexes and compounds of the typical elements. Literature coverage is about a quarter; the main area of neglect is that of reactions of alkyl- and aryl-derivatives of the typical elements. Redox Reactions.-There has been considerable interest in ion-pairing effects on rates of outer-sphere electron-transfer reactions.Activation enthal-pies for the hexacyanoferrate(r1)-hexacyanoferrate(rr1) reaction with gegenion K+ Cs' or H+ have been estimated from 14N n.m.r. spectra in an attempt to evaluate the contribution from enthalpies of formation of ion-pairs to the overall activation enthalpies.' Tracer studies using "Fe and 59Fe on the same hexacyanoferrate electron exchange have provided no evidence for large conjugated cations such as Ph4As+ or (CSHs)2C~+ acting as effective bridges to facilitate electron transfer. The effect of added cations seems to be merely to form ion-pairs and thereby decrease the electrostatic barrier to transition state formation from the like-charged reactants. Further studies of peroxodisulphate oxidation of hexacyanoferrate(I1) permit quantitative estimates to be made of the catalytic activity of added cations.That of Cs+ is some 20 times that of Li' while cations of higher charge have yet greater influence Sr2 + is 870 and La3 + is lo5 times as effective as Li+. These catalytic activities correlate well with those observed for the same cations in the peroxo-disulphate oxidation of i ~ d i d e . ~ Complex formation is important in the iron@)-hydrogen peroxide reaction. In the presence of e.g. chloride or hexafluorophosphate the reactive iron(@ species is the monoligand complex FeL+ ; only for fluoride is further associa-tion to FeF important4 Cerium(rv) oxidations also occur mainly through complexes ; oxidation of thallium(1) in the presence of sulphate occurs primarily by Ce(SO,), in the presence of nitrate by the [Ce(N03)6]2- anion.5 A.Loewenstein and G. Ron Inorg. Chem. 1967,6 1604. ' R. J. Campion C. F. Deck P. King and A. C. Wahl Inorg. Chem. 1967,6 672. ' M. R. Kershaw and J. E. h u e Trans. Faraday SOC. 1967,63 1198. C. F. Wells and M. A. Salam Trans. Faraday SOC. 1967,63,620. ' B. P. Sinha Z . phys. Chem (Leipzig) 1966,233 161 412 366 J . h r g e s s One rarely used criterion for distinguishing between inner- and outer-sphere mechanisms for redox reactions is the volume of activation (AV). Several years ago positive values of AV corresponding to release of co-ordinated water into bulk solvent on formation of an inner-sphere transition-state were reported for oxidations of tetra- and penta-amminecobalt(II1) complexes by iron@).Now AVs for the thallium(1)-thallium(I1I) electron exchange has been found to be negative and large indicating outer-sphere electron transfer in this case.6 Redox reactions involving vanadium(I1) and (111) may be inner- or outer-sphere since rates of electron transfer are often of the same order of magnitude as rates of water displacement from these cations. In oxidations of vanadium(I1) by [Fe(OH2)5L]2+ (L* = C1- NCS- or N3-) there is no evidence for the formation of a VL2 + intermediate and oxidation rates by the three complexes are nearly equal which implies an outer-sphere mechanism; however when [Cr(OH2),(SCN)I2 + is the oxidant an inter-mediate VNCS2 + is detected so here there must be inner-sphere oxidation.' Likewise in the reaction of vanadium(I1) with cis-[Coen,(N,),] + (en = ethyl-enediamine) there is spectrophotometric evidence for transient formation of VNJ2+,* but when [(NH,),Co NH,*CO(NH,)~] is the oxidant reaction with vanadium(r1) must proceed by an outer-sphere path since there are no lone pairs of electrons on the ligands co-ordinated to cobalt which could bond to the vanadium.' Many other reports of oxidations by cobalt(rr1) complexes have appeared.Oxidations of chromium(I1) by [Co(NH3),LI3+ (L = a pyridine with a keto-substituent) show the expected high rates due to chromium(I1) attack at a keto-oxygen atom and subsequent easy electron-transfer across the pyridine ring to the cobalt atom. The unexpected feature is the very small difference between rates for compounds containing a conjugated 4-keto-group and those for analogous compounds containing a non-conjugated 3-keto-group.lo Oxidation of chromium(r1) by [Co acac,] (acac = acetylacetone) has been investigated to determine the difference in reactivity between complexes containing oxygen- and those containing nitrogen-chelating ligands. Lower ligand-field strengths in the former should lead to more rapid electron-transfer." Reaction of [CO(NH,)~L]~' (L = NO2- ONO- or ON02-) with europium(I1) results in ligand reduction to nitrous oxide rather than direct reduction of the cobalt(Irr).'2 Oxidation of titaniurn(rr1) by [Co(NH,),X12 + probably takes place by an inner-sphere mechanism. The evidence adduced is that the trend of increasing rates for the various halides here is similar to those for known inner-sphere reductants chromium(I1) and M.G. Adamson and D. R. Stranks Chem Comm. 1967,648. J. H. Espenson J . Amer. Chem. SOC. 1967,W 1276. J. Doyle and A. G. Sykes J . Chem. SOC. (A) 1967,795. lo E. S. Gould J . Amer. Chem. Soc. 1967,89 5792. l 1 R. G. Linck and J. C. Sullivan Znorg. Chem. 1967,6 171. 'I B. R. Baker M. Orhanovic and N. Sutin J . Amer. Chem. SOC. 1967,89 722. R. T. M. Fraser R. N. Lee and K. Hayden J . Chem. Soc. (A) 1967 741. * Throughout this Report L stands for any ligand whose nature is generally stated in the text; X ztands specifically for a halide ligand Kinetics and Mechanisms of Inorganic Reactions 367 europium(II) and opposite to that observed for the presumed outer-sphere reductant vanadium(r1).Non-bridging ligands often have significant effects on the rates of inner-sphere redox reactions. The use of a series of substituted pyridines (L) in reductions of cis-[Co en2XLI2 + by iron(@ permits some disentanglement of o- and .n-bonding effects since the known pK values for the substituted pyridines give an indication of o-electron release or withdrawal by these substituents. Rate constants are controlled by o-electronic effects since they increase in proportion as the o-bonding strength of the non-bridging ligand decrease^.'^ Oxygen isotopic fractionation factors have been obtained for the reduction of cis- and trans-[Cr(NH,),(OH2)l]2 + by chromium(n). Chromium compounds were used rather than cobalt compounds which were studied in earlier isotopic fractionation experiments because differences be-tween the dimensions of reduced and oxidised species are larger for chromium than for cobalt ; hence the chromium system should be more sensitive to isotopic changes.There is a 1.6% difference between the reduction rates of the trans-( l80H2k and trans-( '60H2)-chromium(~~~) complexes with a much smaller difference for the ciscompounds. These results provide convincing support for Orgel's picture of the effects of non-bridging ligands in tetragonally dis-torted inner-sphere transition states. l 5 Other studies of chromium(I1) reduc-tions of chromium(II1) complexes or in other words chromium(I1) catalysed aquations of chromium(n1) complexes have included those of cis- and trans-[Cr(OH2),C12] +,16 and of the monohypophosphito-complex (H2P02-) of chromium(r~~).~' In the latter case the inverse dependence of rate on hydrogen-ion concentration suggests bridging by both a hydroxyl and a hypophosphite-group in the transition state.A similar inverse dependence of reaction rate on hydrogen-ion concentration in reactions of [Cr(OH2)5Br]2 + and of [CI-(OH~)~I]~ + with chromium(n) as found previously for the analogous reaction of [Cr(OH2),C1I2+ has been interpreted in terms of hydroxyl-rather than halide-bridging in the transition state. The apparently non-bridging halide ligands exert about as much effect on reaction rates here as bridging halidesdoinreactionslike that of[Cr(NH,),XI2 + withchromium(Ir).'* In the similar redox aquation of [Fe(OH2),(NCS)12 + by iron@) the transition state does contain bridging thiocyanate.l9 Oxidation of neptunium(v) by cobalt(rIr)20 or rhodium(mI)21 complexes and reduction of neptunium(v)22 and ( 1 ~ ) ~ ~ by chromium(n) have been studied. I 3 V. W. Cope R. G. Miller and R. T. M. Fraser J . Chem SOC. (A) 1967 301. l4 C. Bifano and R. G. Linck J . Amer. Chem SOC. 1967,89,3945. l 5 J. M. DeChant and J. B. Hunt J . Amer. Chem. SOC. 1967,89,5988. l6 J. H. Espenson and S. G. Slocum Znorg. Chem. 1967,6,906. K. A. Schroeder and J. H. Espenson J . Amer. Chem. SOC. 1967,89 2548. A. Adin J. Doyle and A. G. Sykes J . Chem. SOC. (A) 1967,1504; D. E. Pennington and A. Haim, Znorg. Chem. 1967,6,2138. l9 T. J. Conocchioli and N. Sutin J . Amer. Chem. SOC. 1967,89,282. 'O J. C. Sullivan and R. C. Thompson Znorg. Chem.1967,6 1795. 21 R. K. Murmann and J. C. Sullivan Znorg. Chern 1967,6 892. '' R. C. Thompson and J. C. Sullivan J . Amer. Chem SOC. 1967,89 1098. *3 R. C. Thompson and J. C. Sullivan J . Amer. Chem SOC. 1967,89 1096 368 J . hrgess Tracer ('*O) experiments suggest an inner-sphere mechanism for the nep-tunium(v)-chromium(II) reaction ; the inverse dependence of the rate of the neptunium(rv)-chromium(rr) reaction on hydrogen-ion concentration implies hydroxyl bridging in the transition state. Xenon trioxide oxidation of plutonium(rI1) involves one- or two-electron transfers to give plutonium(v), which reacts with more plutonium(I1r) to give plutonium(1v) as product.24 Stopped-flow techniques have been used to follow a number of oxidations of transition-metal cations by silver@) in order to investigate quantitatively the qualitative impression that silver(I)-(m) is as catalytically active as cobalt(@-(111) for redox reaction^.^' Reductions of copper@) to copper(1) in aqueous solution by vanadium(I1) or by chromium(I1) obey different rate laws implying different mechanisms presumably outer- and inner-sphere respectively.The resultant copper@) solutions proved sufficiently stable for kinetics of oxidation by vanadium(1v) to be followed.26 Another class of reactions which belongs in this section is nucleophilic attack at platinum(rv) since such attack nearly always involves reduction of platinum(1v) to platinum(I1) at an early stage.27 Full discussions of the possible reduction and substitution processes with experimental rate and equilibrium results have been presented for aquation of hexaiodoplatinate(rv)28 and for reaction of iodide with hexabromoplatinate(~v).~~ Somewhat simpler mech-anisms are indicated by the simple second-order rate laws followed by reactions of nucleophiles e.g.I- S2032- or NCS- with cis- and trans- [PtL2X4] (L = trialkyl-phosphine or -arsine). Here the first stage is nucleophilic attack at the platinum and reduction followed by normal nucleophilic substitution in the square-planar platinum(I1) inte~mediate.~' Whether this reduction proceeds by one two-electron transfer or two one-electron transfers is not known but when platinum(1v) complexes are reduced by [Cr bipy312 + (bipy = 2,2'-bipyridyl) there are presumably two one-electron transfers to different reductant cations and therefore transient platinum(II1) intermediates3' Both chloride exchange32 in [Pt diars2C1J2 + diars = o-phenylenebis(dimethy1-arsine)] in the presence of [Ptdiars2] and chloride reaction33 with [Pt(SCN),(NH,)4]2' in the presence of [Pt(NH3)4]2+ have a predominant term in [Pt'"]+ '[Pt"]' '[Cl-] +' in their rate laws suggesting a bridged inner-sphere redox mechanism.Substitution Reactions d3 and 8 Octahedral Complexes.-There has again been extensive study of the kinetics of reactions of pentammine-cobalt (111) 24 J. M. Cleveland Inorg. Chem. 1967,6 1302. " D. H. Huchital N. Sutin and B. Warnqvist Znorg. Chem. 1967,6,838. ' 6 J. H. Espenson K. Shaw and 0. J. Parker J. Amer. Chem. SOC. 1967,89 5730. '' A. A. Grinberg Russ. J. Inorg. Chem.1967,12,444. '* B. Corain and A. J. P& J. Chem. SOC. (A) 1967 1633. 29 E. J. Bounsall D. J. Hewkin D. Hopgood and A. J. P& Znorg. Chim. Acta 1967,1,281. 32 A. Peloso and G. Dolcetti Gazzetta 1967,97,120. 30 A. Peloso and G. Dolcetti J. Chem SOC. (A) 1967 1944; A. Peloso R. Ettorre and G. Dolcetti, 33 W. R. Mason E. R. Berger and R. C. Johnson Inorg. Chem. 1967,6 248. J. K. Beattie and F. Basolo Znorg. Chem. 1967,6,2069. Inorg. Chim Acta 1967 1 307; A. Peloso G. Dolcetti and R. Ettorre Guzzetta 1967 W 955 Kinetics and Mechanisms of Inorganic Reactions 369 complexes. The main points of discussion have been the molecularity of acid aquation reactions and the structure of the transition state; pH depend-ence of acid aquation-rates and the nature of protonated and deprotonated intermediates invoked to explain such dependence; and the mechanism of hydroxide attack.Reactions of pentacyanocobaltate(II1) complexes are con-sidered separately at the end of this section. Acid aquation mechanism. Reports tend to favour unimolecular dissociation for aquation of pentamminecobalt(II1) compounds. Currently known rates for aquation of polydentate methyl-substituted amine chelates have been collected and discussed in terms of conformations of the complexes. There is a dramatic increase in rate with increasing number of axial-methyl substituents which can most readily be explained by increasingly advantageous relief of steric strain in going from six-co-ordinate initial state to a five-co-ordinate transition-state.34 Products from induced aquation of [Co(NH,),X]’ + in the presence of added ions suggest a common five-co-ordinate transition-state.’ Oxygen isotopic-fractionation factors for a variety of leaving groups from [Co(NH,),Ll2 + are also consistent with reaction through a five-co-ordinate transition-state.36 Again induced aquations of cis-[Co en,(N,),] + by NO’, of cis-[Coen,Cl,]+ by Hg2+ and of cis-[Coen,(N,)Cl]+ by NO’ or Hg2+ proceed through one of just two intermediate^.^' Formation constants for ion-pairing with [Co(NH,),(OH,)]’ + and with (Cr(NH,),(OH,)]’ + and rates of subsequent ligand-interchange in the ion-pairs also indicate a five-co-ordinate transition-state for these anation reactions.’* Studies of acid aquation in mixed aqueous solvents often indicate some SN2 character to the process.Rates of aquation of [Coen,LC1I2+ (L = aniline or p-toluidine) in mixed aqueous solutions have been studied as functions of dielectric constant and water concentration. Rates differ greatly in solvents of identical dielectric constant but are proportional to water concentration. The former disfavours a simple &1 process the latter suggests bimolecular aqua-tion.” It is tempting to ascribe the variation of rate of aquation of cis-[Coen,Cl,] + with mole fraction t-butyl alcohol where rates at first decrease slightly then increase rapidly with increasing proportion of t-butyl alcohol first promoting and then breaking down the order of the water to varying availability of water molecules for incorporation in an SN2 transition state.40 However these results could also be explained though less simply in terms of differences in solvation between initial states and five-co-ordinate transition-states.Both kinetics and stereochemistry of aquation of the isomers of 34 M. D. Alexander Inorg. Chem. 1966,s) 2084. 3s D. A. Buckingham I. I. Olsen A. M. Sargeson and H. Satrapa Znorg. Chem 1967,6 1027. 36 G. E. Dolbear and H. Taube Inorg. Chem. 1967,6,60. 37 D. A. Buckingham I. I. Olsen and A. M. Sargeson Znorg. Chem. 1967,6,1807. 38 N . V. Duffy and J. E. Earley J . Amer. Chem Soc. 1967,89,272; C. H. Langford and W. R. Muir, 39 V. D. Panasyuk L. G. Reiter and N. G. Maiboroda Russ. J . Znorg. Chem. 1967,12,206. ‘O J. Burgess Chem. Comm. 1967,1134. ibid. p. 3141; C. H. Langford and W. R. Muu J . Phys. Chem. 1967,71,2602 370 J.hrgess [Co trien C12]+ (trien = triethylenetetramine) indicate some bonding of in-coming water to cobalt in the transition state.41 Differences between mechanisms of aquation of chromium(II1) and cobalt(II1) complexes have been probed in two ways. In aquations of [Cr(NH3)5X]2+ and [Co(NH,),X]’ + group replacement factors which provide a good guide to SN1 and SN2 character for organic substitution reactions indicate greater bond-fission and less bond-formation to incoming water in the chromium(II1) series especially for X = Br- and I- than in cobalt(~rr).~~ On the other hand, comparison of reactivities of [Cr(MeNH2),ClI2 + and [Cr(NH,),C1I2 + with their cobalt(II1) analogues suggests more SN1 character in the cobalt(n1) aqua ti on^.^^ If one accepts that aquation of pentamminocobalt(rrr) complexes is SN1 in character then the next problem is whether the transition state is square pyramidal as expected from crystal field considerations or trigonal bi-pyramidal.Current efforts to distinguish between these two possibilities are based on competition experiments using a variety of anions and applying p.m.r. spectroscopy to the products. These studies favour the square 44 An alternative approach has just been started in which aquation rates of complexes containing the rigid ligand cyclam (1,4,8,1 l-tetraazacyclo-tetradecane) are compared with those for analogous complexes of flexible ligands.4’ Efsects ofpH. The continuing interest in this area may be illustrated by the reports on acid aquation of cis- and tr~ns-[Coen,(NO,)~]+,~~ and on isomer-isation of trans-[Co bipy,(NOz)(OH2)]2 +.In the latter case protonated, viz. trans-[Co bipyz(N02H)(OH,)]3 + and deprotonated viz. trans-[Co bipy,(NO,)(OH)] + species both appear in the postulated mechani~m.~’ Relevant to these and to numerous other cases where intermediates containing protonated nitro-ligands have been invoked i; the demonstration that the compound prepared by Jarrgenson in 1894 and formulated as [CO(NH,)~(NO,),]NO~.HNO~ is in fact [CO(NH,),(NO~)(NO~H)](N~~)~, containing a protonated nitr0-1igand.~~ Protonated intermediates have also been suggested in aquations of chromium(rI1) complexes ;49 while away from transition-metal chemistry it has been shown that hydrolysis of hexafluoro-germanates” proceeds by parallel reactions of [GeF,]’ - and [GeF,H] -.Mechanism of base hydrolysis. The SN1 CB vs. SN2 controversy has yet to be resolved. Orders of reaction for hydroxide attack at [Codien(NO,),] (dien = diethylenetriamine) and at [Co en (NO,),] - are second and first respectively. 41 A. M. Sargeson and G. H. Searle Inorg. Chem. 1967,6,2172. 42 S. C. Chan and K. Y. Hui Austral. J . Chem. 1967,20,893. 43 M . Parris J . Chem. SOC. (A) 1967 583. 44 D. A. Buckingham I. I. Olsen and A. M. Sargeson Austral. J . Chem. 1967,20,597. 45 C. K. Poon and M. L. Tobe J . Chem. SOC. (A) 1967,2069. 46 P. J. Staples J . Chem. SOC. (A) 1967,45. *’I U. D. Gomwalk and A. McAuley J . Chem. SOC. (A) 1967 1796. 48 R. Ugo and R. D. Gillard J . Chem. SOC. (A) 1967,2078. 49 E.g. J. E. Finholt and S.N. Deming Inorg. Chem. 1967,6 1533. A. E. Gebala and M. M. Jones J . Inorg. Nuclear Chem. 1967,29,2301 Kinetics and Mechanisms of Inorganic Reactions 37 1 The presence of more electron-withdrawing nitro-groups in the latter com-pound should facilitate proton loss to give an SNlCB transition state; they should also facilitate simple sN2 attack by hydroxide. In either of these cases a larger second-order rate constant would be expected for the tetra- than for the tri-nitro-complex. In fact there is no second-order rate term for the tetranitro-complex. These results are rationalised by assuming an ion-pairing pre-equilibrium which would be unfavourable to the tetranitro-complex since this bears a negative charge followed by ligand interchange i.e. an sN21P rnechani~m.’~ Other similar but somewhat more intricate examples and argu-ments all support widespread applicability of the sN21P mechanism to base hydrolysis of cobalt(n1) c~mplexes.’~ Ion-pairing with hydroxide is less exten-sive for [Cren,l3+ than for [Coen3l3+ which may account for slower base hydrolysis of the former cornpo~nd.’~ A different approach to this problem was the investigation of product ratios from base hydrolysis of truns-[C~(NH,),(~ ’NH3)L]’ + .Each complex (L = Cl- Br- or NO,-) gave 50% cis and 50% trans products. As no re-arrangement can occur in the time for base hydrolysis one may infer firstly, from the equality of the cis trans product ratios that all three complexes react by way of the same transition state and secondly that the transition state is a trigonal bipyramid with the amido-group e q ~ a t o r i a l .~ ~ Base hydrolysis of rhodium(II1) complexes poses the same problems with fairly convincing arguments advanced both for the SNlCB55 and SN256 mechanisms while the kinetics of reactions of difluoramine raise the same question again. This compound reacts with a variety of anions the reactions in all cases following second-order kinetics. The second-order rate constants correlate well with nucleophilicities implying SN2 reaction except for the hydroxide ion which alone among the anions could abstract a proton from difluoramine and react by an SNlCB rnechani~rn.’~ The most interesting contribution to this field has been the suggestion that the rate-determining step in base hydrolysis is electron transfer from a hydroxyl ion to cobalt(IrI) giving a labile cobalt(n) complex intermediate.This idea is consistent both with many observations from preparative cobalt chemistry, and with kinetic differences between cobalt(rrr) rhodium(rrr) and chromium-( I I I ) . ~ ~ There is supporting evidence from similar systems. Thus [CO(NH,)~(NO~)]~+ is not aquated directly in an acetate buffer but it does react to give cobalt in the + 2 oxidation state.59 This presumably results from initial electron transfer to the cobalt; the electron probably comes from the ’’ S. C. Chan and P. Y. Leung J . Chem. SOC. (A) 1967,2089. 52 S. C. Chan and F. Leh J . Chem. SOC. (A) 1967,288; S. C. Chan C. Y. Cheng and F. Leh ibid., 53 S. C. Chan J . Chem. SOC. (A) 1967,2103. 54 D.A. Buckingham I. I. Olsen and A. M. Sargeson J . Amer. Chem. SOC. 1967,89,5129. ” A. Panunzi and F. Basolo Inorg. Chim. Acta 1967,1,223. ’‘ S . C. Chan Austral. J . Chem. 1967,20 61. ” W. T. Yap A. D. Craig and G. A. Ward J . Amer. Chem. SOC. 1967,89,3442. ’* R. D. Gillard J . Chem SOC. (A) 1967,917. ” D. Banerjea J . Inorg. Nuclear Chern. 1967,29 2795. p. 1586; S. C. Chan Austral. J . Chem. 1967 20 1753 372 J . hrgess anion rather than from the cationic ligands as in base hydrolysis5* or thermal decomposition of [CO(NH,),]~ + and [Co(NH3),XI2+ salts.60 Isomerisation of cis-[Coen,Cl,J + is accelerated by irradiation at the charge-transfer fre-quency though not at the d -+ d-transition frequency which again implies formation of labile cobalt(I1) by electron transfer from the chloro-ligand.6 Further recent examples of reactions which are induced or accelerated by irradiation at an appropriate frequency include oxidation of hexacyanofer-octacyanotungstate(rv) and octacyanomolybdate(~v)~~ by irradiating at the charge-transfer frequency and aquation of hexacyanoferrate(I1) by irradiating at the d + d-transition frequency.64 Irradiation of hexacyano-ferrate(m) at 366 mp which is in both charge-transfer and d + d-transition absorption regions results in simultaneous reduction and a q ~ a t i o n .~ ~ [CO(NH~)~(O~C*CCI,)J~ + and [Rh(NH3),(02CR)12+ follow an unusual rate law having a term in [OH-I2 as well as in [OH-). The former term is thought to be due to a reaction pathway similar to that in the Cannizzaro reaction which involves an intermediate with negative charges associated with each of the two ester-oxygen atoms.66 PentacyanocobaZtate(n1) compounds.Kinetics of aquation of [Co(CN),XJ3 -and of anation of [Co(CN),(OH,)l2- are consistent with a limiting S,l mechanism for both reactions.67 Studies of replacement of water in [Co(CN),(OH,)l2- have afforded interesting comparisons of nucleophilic reactivity of some nitrogen-containing species. Pyridine is more reactive, though less basic than ammonia; N2H5+ is as reactive as N2H in this reac-tion.68 Intermediates containing protonated cyano-ligands seem to be involved in only some reactions conducted in acid media. Kinetic and n.m.r. evidence indicates that cyanide insertion into pentacyanopyridiomethyl-cobaltate(n1) anions occurs by way of a cyano-protonated intermediate:' whereas there is no evidence that cyano-protonated intermediates are involved in cyanide reaction with [CO(CN)~(SO,)(OH,)]~- in acid sol~tion.'~ The sulphito-group has a large labilising influence which may be.due to its acting as a bidentate ligand in the transition state.This labilising effect is also illustrated7 by the much faster acid-aquation of tr~ns-[Co(CN),(S0,),]~ -than of [CO(CN),(SO,)]~-. Base hydrolysis of [Co(CN),(S2O3)I4- takes place Alkaline hydrolyses of the ester-containing complexes 6o N. Tanaka and K. Nagase Rill. Chem SOC. Japan 1967,40,546. 61 S. Kawaguchi and H. Fujioka tfrll. Chem. SOC. Japan 1967,40,802. 62 S. Ohno Rill. Chem. SOC. Japan 1967,40,1770. 64 S. Ohno Rill. Chem. SOC. Japan 1967,40 1765." J. Legros Compt. rend. 1967,265 C 225. 66 N. S. Angerman and R. B. Jordan Znorg. Chem. 1967,6,379; F. Monacelli J . Inorg. Nuclear 67 R. Grassi A. Haim and W. K. Wilmarth Inorg. Chem. 1967,6,237. 69 M. D. Johnson M. L. Tobe and Lai-Yoong Wong Chem. Comm. 1967,298. 70 P. H. Tewari R. W. Gaver H. K. Wilcox and W. K. Wilmarth Inorg. Chem. 1967,6,611. W. L. Waltz A. W. Adamson and P. D. Fleischauer J . Amer. Chem. SOC. 1967,89,3923. Chem. 1967,29,1079. R. Barka J. Ellis Maak-Sang Tsao and W. K. Wilmarth Znorg. Chem. 1967,6,243. H. H. Chen M.4. Two R. W. Gaver P. H. Tewari and W. K. Wilmarth Inorg. Chem. 1966, 5 1913 Kinetics and Mechanisms of Inorganic Reactions 373 at rates independent of hydroxide-ion c~ncentration.~~ The SN1 mechanism seems to be favoured for base hydrolysis of cobalt(II1) complexes containing many electron-withdrawing ligands (cf.[Coen (NO,),] - above) in contrast to the SN 1 CB or sN21P mechanism for polyamminecobalt(1rr) complexes con-taining few or no electron-withdrawing ligands. Substitution Reactions Other Octahedral Complexes.-Aquo-complexes. An example of a complex-formation reaction in which the rate-determining step is loss of water from the metal ion is that of hydrated zinc@) or C O P ~ ~ ( I I ) with m~rexide.~ In the reaction of hydrated cobalt(r1) or nickel@) with a-aminobutyric acid water-loss from the cation is again rate-determining but with P-aminobutyric acid steric hindrance causes ring closure of monodenate intermediate to the chelate product to be rate-determir~ing.~~ In other cases of complex formation bonding of incoming ligand to metal is important in the rate-determining step.Thus the reaction of hexa-aquonickel(I1) with acetyl-acetone is first-order in each component implying an s N 2 mechanism for complex f~rmation.~' Rates of reaction of hydrated zinc(@ or nickel(@ with a variety of substituted dithizones depend greatly on the nature of the substituent. The difficulty here is that all substituted dithizones react more quickly than dithizone itself no matter whether the substituent be an electron-donor or -withdrawer. It is however possible to rationalise this sort of situation in terms of balance between opposing 6- and .n-bonding effects in the transition state.76 In all the forementioned cases the metal has been in the + 2 oxidation state.For cations in the + 3 and higher oxidation states kinetics of water replacement become complicated by a tendency for both [M(OH2)6]n+ and [M(OH2)5(OH)]("-1)+ to react with the incoming ligand for instance in the formation of oxalato-complexes of iron(111).~ Reaction of iron(m) with a i d e is further complicated by the alternative possibilities of attack by N3- or HN,. The two reactions [Fe(OH2)6I3' plus N3- and [Fe(OH,)S(OH)]2+ plus HN would both give the same expression in the rate law ; the activation entropy corresponding to this term suggests the former reaction by analogy with activation entropies known for similar reactions.78 The other term in the iron(m) plus azide rate law corresponds to N,- attack at [Fe(OH2)5(0H)]2+.As the second-order rate constant is similar to those for reaction of other anions with this cation rate-determining water release from iron is implied for all these processes.79 Replacement of a ligand water-molecule by chloride does not alter the kinetic pattern; both [Fe(OH2)&1I2+ and [Fe(OH2)4(0H)Cl]+ react with water or with aquated iron(II).80 72 D. Banerjea and T. P. das Gupta J . Znorg. Nuclear Chem. 1967,29 1021. 73 A. Bewick and P. M. Robertson Trans. Faraday SOC. 1967,63,678. 74 A. Kowalak K. Kustin R. F. Pasternack and S. Petrucci J . Amer. Chem SOC. 1967,89,3126. 'Is J. J. Casazza and M. Cefola J . Znorg. Nuclear Chem. 1967,29,2595. 76 J. S. Oh and H. Freiser Analyt. Chem. 1967,39 295. 77 E. G. Moorhead and N. Sutin Znorg. Chem. 1966,5,1866. '* D.W. Carlyle and J. H. Espenson Znorg. Chem. 1967,6,1370. 79 F. Accascina F. P. Cavasino and S. D'Allesandro J . Phys. Chem 1967,71,2474. 8o E. G. Moorhead and N. Sutin Znorg. Chem. 1967,6,428 374 J . hrgess Kinetics of reaction of vanadium(n1) with thiocyanate have been compared with those for the much-studied reactions of chromium(1rr) or iron(m) with this anion. The activation energy for complex formation is lowest for vanadi-um(@. S,2 reaction would be favoured for vanadium(m) since its d2 con-figuration leaves one tzg orbital vacant for ready nucleophilic attack.8 ’ Complex-formation reactions of the oxocations V 0 2 + and U02’ + probably take place by an SN2 mechanism since rates vary greatly with incoming ligand. The fast rates observed (T-jump techniques were necessary) may be due to electron-withdrawal by the oxygen leaving the metal more positive than implied by its formal oxidation state.82 Replacement of some water ligands by other ligands affects the reactivity of those which are left.Thus water molecules in [Ni(NCS)4(OH)2)2]2 - are much more labile than those in [Ni(OH2)6]2+ ;83 while both geometric and electronic effects of polyamine and aminocarboxylate ligands affect the reactivity of remaining water molecules on nickel@) to replacement by ammonia.84 Complexes of ethylenediamine tetra-acetic acid (edta) and its deriuatiues. Transfer of these multidentate ligands from one metal ion to another con-tinues to be studied assiduously. Usually reactions involving complete ligand-dissociation from the first ion followed by association with the second and reactions involving intermediates with the ligand bonded simultaneously to two cations proceed in parallel; examples include transfer from zinc@) to ~obalt(rr)~’ and vice uersaB6 and from copper(11) to lead@) and lead@) to Simultaneous bonding of one cation to two of these ligands in an intermediate has been demonstrated in the transfer of iron(1n) from edta to metal-binding sites in tran~ferrin.~’ In the displacement of edta or cyclo-hexylenediamine tetra-acetate from copper(@ by polyamines three nitrogen atoms from the incoming ligands become attached to the copper before the rate-determining step of the reaction.88 Solvent exchange.Rates and activation parameters have been determined by n.m.r. methods for exchange of dimethyl ~ulphoxide,~~ and of methyl cyanide,’O at nickel(II) of dimethyiformamide at aluminiurn(~~~),~’ and of water at oxovanadium(~v).~~ Interpretation of the results for the vanadyl-water system is complicated by the presence of both axial and equatorial water molecules.The application of n.m.r. methods to the study of solvent-exchange rates has been extended to lanthanide and actinide cations by the determination B. R. Baker N. Sutin and T. J. Welch Inorg. Chem. 1967,6 1948. P. Hurwitz and K. Kustin J . Phys. Chem. 1967,71 324. 83 R. B. Jordan H. W. Dodgen and J. P. Hunt Znorg. Chem. 1966,5 1906. 84 D. W. Margerum and H. M. Rosen J . A m . Chem. Soc. 1967,89,1088. S . S. Krishnan and R. E. Jervis J . Inorg. Nuclear Chem. 1967,29 1973. 86 H. Ogino and N.Tanaka &ll. Chem. SOC. Japan 1967,40,852,857. G. W. Bates C. Billups and P. Saltman J . Hol. Chem. 1967,242,2816. J. D. Carr R. A. Libby and D. W. Margerum Znorg. Chern. 1967,6 1083. 89 S. Thomas and W. L. Reynolds J . Chern. Phys. 1967,46,4164. 90 D. K. Ravage T. R. Stengle and C. H. Langford Znorg. Chern. 1967,6 1252. 91 A. Fratiello and R. Schuster J . Phys. Chem. 1967,71 1948. 92 J. Reuben and D. Fiat Znorg. Chem. 1967,6,579; K. Wiithrich and R. E. Connick ibid. p. 583 Kinetics and Mechanisms of Inorganic Reactions 375 of rates of tributyl phosphate exchange at praseodymium(rn) thorium(rv) and dioxouranium(~).~~ Substitution Reactions Tetrahedral Compounds.-Most ieports have, of course related to compounds of the Group n’ elements. Particularly for silicon and germanium compounds the interest tends to be organic; the most comprehensive investigations of tin and lead chemistry have been of metal-carbon bond-breaking in tetra-alkyls under a wide range of condition^.'^ Two examples of substitution reactions in tetrahedral transition-metal complexes have been reported.Exchange of 2-picoline with [Co(2-picoline),C1,] in [2H,]acetone,95 and exchange of triphenylphosphine with [Ni(PPh,),X,] and with [CO(PP~,),X,],~~ have been followed from line-broadening in IH n.m.r. spectra. In both cases second-order kinetics were obeyed implying an S,2 process and cativation entropies were large and negative consistent with formation of a transition state in which the co-ordination number of the metal is increased. Substitution Reactions Square-planar Complexes.-Volumes of activation for aquation of [PtCl,]2- and of [Pt(NH,)Cl,]- are large and negative, implying a high degree of incorporation of water from the bulk solvent into the transition state.The authors infer that two platinum to incoming-water bonds are almost fully formed in the transition state with little loosening of the platinum-to-chloride bonding.” Kinetics of displacement of [ SnCl,] - by thiocyanate selenocyanate or thiourea from trans-[Pt(PPh,),Pb(SnCl,)] in various solvents have been compared with displacement of chloride from the analogous chloro-complexes by the same ligands. The rate law for [SnCl,]-displacement is of the usual form for square-planar complexes viz. rate = k,[complex) + k,[complex] [Y -3 ; differences between ease of displacement of [SnCl,] - and of C1- stem from greater platinum-ligand n-interaction with the former.’* Rates of displacement of chloride from [AuCl,]- by various nucleophiles have been compared with those for analogous substitution reactions at platinum(r1).The discriminating power of gold(rn) is much greater than that of platinum(@ as metal-to-incoming-ligand bonding seems to be more fully developed in the transition state for gold(111).~~ The rate law for reaction of cis- and trans-[Pd(NH,),Cl,] in hydrochloric acid is of the expected form viz. rate = k,[complex] + k,[complex] [Cl-1, with no term in hydrogen ion concentration. However such terms do appear in the rate laws for reaction of related complexes containing polyamines 93 T.H. Siddall and W. E. Stewart Inorg. Nuclear Chem. Letters 1967,3 279. 94 M. Gielen and J. Nasielski J . Organometallic Chem. 1967,7 273; S. Boue M. Gielen and J. Nasielski J . Organometallic Chem. 1967,9 443 461 481; H. Horn and F. Huber Monatsh. 1967, 98 771. 95 S. S. Zundahl and R. S. Drago J . Amer. Chem. Soc. 1967,89,4319. 96 W. de W. Horrcicks and L. H. Pignolet J . Amer. Chem. SOC. 1966,88,5929. ” H. E. Brower L. Hathaway and K. R. Brower Inorg. Chem. 1966,5 1899. 98 G. Faraone V. Ricevuto R. Romeo and M. Trozzi Gazzetta 1967,97,810. 99 L. Cattalini A. Orio and M. L. Tobe J . Amer. Chem. SOC. 1967 89 3130 376 J . hrgess rather than ammonia and may result from participation of five-co-ordinate intermediates e.g. [PdCl,(NH,- CH,. CH NH,)] -. Such intermediates could be stabilised somewhat by internal hydrogen-bonding and might then require attack by a second proton to release the polyamine.loO Kinetics of reactions of square-planar nickel(1r) complexes have also been reported.Initial reaction between tetraglycinatonickel(i1) and polydentate amines occurs by a first-order process whose rate is independent of both the nature and the concentration of the amine. Nitrogen to tetraglycine bond breaking is clearly rate-determining. O1 Hydrolysis of ethylenebisbiguanidine-nickel(@ in acid solution proceeds through pre-equilibrium with ligand-protonated forms followed by rate-determining MKel-ligand bond fission. l o 2 Substitution Reactions Organometallic Compounds.-Carbon monoxide displacement. The general rate-law for replacement of carbon monoxide in a metal carbonyl by a ligand L takes the form rate = k,[carbonyl] + k,[carbonyl] [L] which corresponds to simultaneous SN1 and SN2 processes.One of the terms is often undetectably small indicating that the corresponding reaction path is of negligible importance. Rate laws have been determined for many metal carbonyls so that the carbon monoxide displacement mechanism can be ascertained in each particular case. The earlier investigation of Mo(CO), has been extended to the other Group VI hexacarbonyls. In all three cases both terms appear in the rate law and the respective activation entropies are consistent with the SNl and SN2 assignments. The ratio of the rate constants varies in accordance with relative favouring of the SN2 pathway as the radius of the metal atom increases and thus facilitates formation of a transition state of higher co-ordination number.Io3 Substitution reactions at four-co-ordinate manganese in Mn(CO)(NO), and at five-co-ordinate manganese in Mn(CO),(NO) are both &2 whereas for octahedral Mn(CO),(NO)L the mechanism is primarily SNl.Io4 Displace-ment of CO by PPh3 from Fe(CO),(PPh,) follows first-order kinetics;"' the difference between SN2 reaction at fiveco-ordinate manganese and sNl at five-co-ordinate iron may arise from the greater number of d electrons around iron.Another example of the effect of change in the central metal atom on the kinetics of substitution reactions is afforded by reactions of [Mn(CO),X], and [Re(CO),X],. Substitution in the manganese compound occurs by parallel SN1 and S N 2 reactions,106 but in the rhenium compound solely by SN2.107 Again as in the example of the Group VI hexacarbonyls above, formation of a seven-co-ordinate transition-state in an SN2 process is easier for the larger atom.Other ligands in metal carbonyls affect the ease of replacement of the l o o A. J. Po& and D. H. Vaughan Znorg. Chim. Acta 1967 1 255. N. W. H. Ma D. A. White and R. B. Martin Znorg. Chem. 1967,6 1632. lo* D. J. MacDonald J . Znorg. Nuclear Chem. 1967,29 1271. J. R. Graham and R. J. Angelici Znorg. Chem. 1967,6,2082. Io4 H. Wawersik and F. Basolo J . Amer. Chem. SOC. 1967,89,4626. E. E. Siefert and R. J. Angelici J . Organometallic Chem. 1967,8 374. lo6 F. Zingales and U. Sartorelli Znorg.Chem. 1967,6 1243. lo' F. Zingales U. Sartorelli F. Canziani and M. Raveglia Znorg. Chem. 1967,6 154 Kinetics and Mechanisms of Inorganic Reactions 377 carbon monoxide. In substitution reactions of M(C0)4L (M = Cr Mo or W ; L = a substituted 1,lO-phenanthroline) the first-order rate constants for the S,l reaction path correlate linearly with pK values for the respective sub-stituted l,lO-phenanthrolines.'oa The ligand substituents have a greater effect on Q- than on x-bonding as they do in nucleophilic addition of olefms to rhodium(1) compounds.10g All the preceding examples except those of the halogen-bridged [ Mn(CO)4X] and [ Re(CO),X] dimers involve metakarbon bond-breaking in the first reaction step. This first step has also been assumed for substitution reactions in Mn,(CO)lo but it has now been argued that fission of the relatively weak Mn-Mn bond rather than of a Mn-C bond is a more likely initial reaction.' ' O Displacement of other ligands. Replacement of the two ligands L from M(CO)4L2 (M = Cr Mo or W; L = PCl, py 1,5-cyclo-octadiene etc.) by 2,2'-bipyridyl or by diphos Ph2P- [CH,] PPh follows first-order kinetics. Good x-bonding ligands lead to large differences between rate constants for the respective derivatives of the three metals whereas poor n-bonding ligands lead to small differences. The ease of replacement of ligands shows no cor-relation with the reactivity of the same ligands as entering ligands in substitution reactions e.g. in molybdenum hexacarbonyl.' '' Displacement of cyclo-octa-1,5-diene (cod) from Mo(CO)~CO~"'~* '12 follows the two-term rate law already described for carbonyl displacement reactions (vide supra).In this case the experimental evidence is consistent with rate-determining cleavage of metal-diene bonding for the first-order term but whether the second-order term correspondings to nucleophilic attack by the incoming ligand at molyb-denum or to pre-equilibrium with an intermediate containing monodentate cyclo-octa-l,5-diene cannot be unequivocally decided from the experimental results. Displacements of cycloheptatriene from M(CO),(C,Ha) (M = Cr Mo, or W) and of L from Mo(CO),L (L = benzene or methyl-substituted benzenes) by trimethylphosphite are both second-order reactions SN2 in character. ' l3 Which ligand is attacked first in mixed cyclopentadienyl-carbonyl compounds depends both on the attacking reagent and on the metal.For example C6F,Li attacks the cyclopentadiene ring first in [(x-C,H,)Fe(CO),(PPh,)l + but reacts with the similar cation [(7c-C,H,)Mo(CO),(PPh3)] + to give a penta-fluorobenzoyl derivative. ' Carbonyl insertion and similar reactions. Reinvestigation of the carbonyl-insertion reaction into (Me)Mn(CO)S using [ "C]carbon monoxide has lo' R. J. Angelici and J. R. Graham Znorg. Chem. 1967,6,988; J. R. Graham and R. J. Angelici, log R. Cramer J . Amer. Chem. SOC. 1967,89,4621. 'I1 (a) M. Graziani F. Zingales and U. Belluco Znorg. Chem. 1967 6 1582; (b) F. Zingales, ibid. p. 992. D. Hopgood and A. J. Po& Chem. Comm. 1966,831. F. Canziani and F. Basolo J. Organometallic Chem.1967,7,461. F. Zingales M. Graziani and U. Belluco J . Amer. Chem. SOC. 1967,89,256. A. Pidcock J. D. Smith and B. W. Taylor J . Chem. SOC. (A) 1967,872; A. Pidcock and B. W. P. M. Treichel and R. L. Schubkin lnorg. Chem. 1967,6 1328. Taylor ibid. p. 877 378 J . hrgess demonstrated that “insertion” of carbon monoxide involves methyl migration followed by attachment of carbon monoxide to the manganese (l).”’ Similar methyl migration occurs in reactions of (n-CSHS)Fe(CO),(Me) and of (n-CSHS)Mo(CO)3(Me).116 Sulphur dioxide inserts into (allyl)Mn(CO) more rapidly than into (Me)Mn(CO),. Insertion occurs via a cyclic transition-state (2); the allyl-carbon attached to the manganese in the initial compound is furthest from the metal in the product.”7 A nitrogen molecule ligand can be attached to iridium by bimolecular attack of RCO*N on Ir(CO)L,Cl through the transition state shown in (3) to give IrL,ClN,.118 Molecular nitrogen can be added to (CSHJ2TiC1 in the presence of EtMgBr; the mechanism may involve addition of the nitrogen to zerovalent titanium at an intermediate stage.’ ’ OC-Mn-CO 0 4 0 co I /L C1- 1r’-N4OR HC L’l I N=N Reactions of Co-ordinated Ligands.-Alkaline hydrolysis of the ester linkage in ethyl glycinate is about one hundred times faster when the ester is co-ordinated to cobalt (rrr) in the cis-[Coen,Cl(NH *CH *CO2Et)I2+ cation,’20 while bromination of co-ordinated aniline in trans-[Co en,(OH,) (NH2Ph)l3+ is much slower than bromination of free aniline.12’ Both these results are consistent with the expected effects of cobalt(rI1) on the distribution of electrons in the organic molecules.Peptide formation is catalysed by co-ordination of one of the components to cobalt(IrI) which acts as an end-group protector as well as a catalyst.12* Rates of iodination of 5-sulphonato-8-hydroxyquinoline complexes vary greatly with the nature of the transition-metal cation as do rates of hydrogen or deuterium exchange with complexed edta.’24 In the latter case rate constants correlate well with metal-ligand bond strengths. In the organometallic field co-ordination of tricarbonylchromium to esters of benzoic acid results in acceleration of rates of ester hydroly~is.’~’ An initial investigation into the kinetics of oxidation of K. Noack and F. Calderazzo J .Organometallic Chem. 1967,10 101. I. S. Butler F. Basolo and R. G. Pearson Znorg. Chem. 1967,6,2074. J. P. Collman M. Kubota J.-Y. Sun and F. Vastine J . Amer. Chem. Soc. 1967,89 169. R. Maskill and J. M. Pratt Chem. Comm. 1967,950. 11’ F. A. Hartman P. J. Pollick R. L. Downs and A. Wojcicki J . Amer. Chem. SOC. 1967,89,2493. 120 R. W. Hay M. L. Jansen and P. L. Cropp Chem. Comm. 1967,621. 121 N. K. Chawla D. G. Lambert and M. M. Jones J . Amer. Chem. SOC. 1967,89 557. 122 D. A. Buckingham L. G. Marzilli and A. M. Sargeson J . Amer. Chem. SOC. 1967 89 2772, 12’ R. C. McNutt and M. M. Jones J . Znorg. Nuclear Chem. 1967,29 1415. 12* J. B. Terrill and C. N. Reilley Analyt. Chem. 1966,38,1876. 4539. G. Klopman and F. Calderazzo Znorg. Chem. 1967,6,977 Kinetics and Mechanisms of Inorganic Reactions 379 co-ordinated ligands has been reported for oxidation of [CO(NH,),(NCS)]~+ by hydrogen peroxide.' 26 Intramolecular Reactions.-Inversion barriers for forty-six pyramidal AB compounds have been predicted from vibrational frequencies and molecular dimensions.Values range from 1-2 kcal.mole-' for H30+ to 7.5 for Me,N and 74 for PCl ; they are in line with experimental observations on resolution of isomers and heights of inversion barriers determined from n.m.r. ~pectra.'~' New results for barriers to inversion at nitrogen in a series of 1-alkylaziridines illustrate the importance of steric factors.' 28 Rates of thermal racemisation at pyramidal sulphur are the same for 1 -adamantylethylmethyl-sulphonium perchlorate and t-butylethylmethylsulphonium perchlorate.The 1-adamantyl and t-butyl groups are the same size but have very different electronic effects. The observed equality of racemisation rates therefore indicates sterically-governed inversion and not dissociation followed by recombination as the racemisation mechanism. ' 29 Inversion at pyramidal sulphur in platinum complexes of sulphur ligands is much faster than expected from known inversion rates of organic sulphur compounds so the process is considered to be not simple inversion at the sulphur but to involve platinum d orbitals in a more complicated mechanism of conformational change. 130 The question of intermolecular vs. intramolecular fluorine exchange in SF, is still in dispute. 1.r. spectroscopy provides the latest evidence but the definitive answer awaits the observation of the 33S h.m.r.spectrum of a enriched specimen of this cornpo~nd.'~' The "F n.m.r. spectrum of PF has now been studied in solution in dichloromethane. The dependence of line-width on PF concentration indicates a solvent-assisted intramolecular mech-anism for time-averaging the environments of the five fluorine atoms.132 Ease of intramolecular racemisation of AB5 compounds through trigonal bi-pyramidal-square pyramidal interconversion has been discussed. ' 33 The temperature dependence of the "F n.m.r. spectrum of (PCF,) has been interpreted in terms of pseudo-rotation of the ring as in cyclopentane.134 The temperature dependence of the n.m.r. spectra of the methyl protons of Sn acac,Cl implies exchange between two distorted octahedral configura-t i o n ~ ' ~ ~ with a barrier of 5.4 kcal.mole-'.Similar studies of cis-Tiacac2X2 indicate an energy barrier of 11-12 kcal.mole- '. Possible mechanisms for lZ6 K. Fchug M. D. Gilmore and L. A. Olsen Inorg. Chem. 1967,6,2180. G. W.,Koeppl D. S. Sagatys G. S. Krishnamurthy and S. I. Miller J . Amer. Chem. Soc. 1967, 89 3396. 12' S. J. Brois J . Amer. Chem. Soc. 1967,89,4242. lZ9 R. Scartazzini and K. Mislow Tetrahedron Letters 1967 2719. 130 P. Haake and P. C. Turley J . Amer. Chem. Soc. 1967,89,4611; P. C. Turley and P. Haake, 13' E. L. Muetterties and W. D. Phillips J . Chem. Phys. 1967,46,2861; R. L. Redington and C. V. 13' S. Brownstein Canad. J . Chem. 1967,45 1711. 133 E. L. Muetterties Inorg. Chem. 1967,6 635.134 E. J. Wells H. P. K. Lee and L. K. Peterson Chem. Comm. 1967 894. 13' Y. Kawasaki and T. Tanaka Inorg. Nuclear Chem. Letters 1967,3 13. ibid. p. 4617. Berney ibid. p. 2862 380 J . h r g e s s configurational change are discussed ; those involving twists of the diketone ligands or formation of intermediates containing monodentate diketone molecules seem most plausible.'36 Solutions of aluminium complexes of two different fJ-diketones (AA and BB) yield on mixing a solution containing all four simple and mixed complexes. From the 'H n.m.r. spectra of such solutions, rates and activation parameters for inversion of the complexes Al(AA)(BB), and Al(AA),(BB) have been obtained. Rates are independent of concentration of complex and of (an excess of) free ligand implying an intramolecular mechanism.' 37 Features of several possible intramolecular isomerisation mechanisms have been discussed.138 Rearrangement of Ti def,F (def = diethylformamide) involves both intramolecular movement of the fluorine atoms and reversible loss of the diethylformamide. 13' Conformational changes in organometallic compounds can often be followed by 'H n.m.r. spectroscopy e.g. syn and anti protons in a n-methallyl group can interchange their environments through a o-bonded intermediate. This interchange is reflected in the change in the 'H n.m.r. spectrum of (n-C4H7)RhL2C12 with temperature. Activation enthalpies decrease as the electron-releasing power of the ligand L increase^.'^' Preliminary rate-data have been reported for conformational changes in C O L ~ ~ + for L = a variety of bidentate ligand~.'~' The barrier to chelate ring inversion in [Coen3]C13 has been e~tirnated',~ to be 10.5 kcal.mole-' from line-widths of n.m.r. spectra of solutions of this compound in [2H6]acetone. 136 R. C. Fay and R. N. Lowry Znorg. Chem. 1967,6,1512; N. Serpone and R. C. Fay ibid. p. 1835. J. J. Fortman and R. E. Sievers Znorg. Chem. 1967,6 2022. 13' C. S. Springer and R. E. Sievers Inorg. Chem. 1967,6 852. lJ9 D. S. Dyer and R. 0. Ragsdale J . Amer. Chem SOC. 1967,89 1528. 140 K. Vrieze and H. C. Volger J . Organometallic Chem. 1967,9 537. 14' D. A. Buckingham L. Durham and A. M. Sargeson Austral. J . Chem. 1967 20,257. 14' B. M. Fun& J . Amer. Chem SOC. 1967,89 5788

ISSN:0069-3022    

DOI:10.1039/GR9676400365

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

ERRATA Vol. 63 1966 Page 157 line 8*. Page 158 line 21. Page 159 line 16. Page 160 line 16. Page 172 line 9*. line 8*. Page 173. Delete reference below formula. Page 176 line 23. Page 188 Ref. 32. Page 346 line 4. Page 426 line 9. Page 426 line 21. For cyclobutanes read cyclobutenes. Page 427 Footnote. For tetracyclone read cyclones. Page 432. The equilibrium sign between (71) and (74) should be in square Page 432 Formula (75). Page 434 line 12*. For H, z 7.0 read H z 8-0. Page 507 Ref. 53. Page 529 bottom line. Page 530 line 9. Page 532 line 12. line 17. Page 595 line lo* For Studies on Other a-Glugans read Studies on Other a-Glucans. Page 643. Page 646. Page 745 Ref. 420. The C 4 bond length in the C ring is 1.37 and not 1.73. Page 761.Ref. 563. For M. Sundaralingam read M. Sunderalingam. Page 761 line 22. The angle between the base and the ribose is displaced by more than 0-5 8 from the plane of the remaining ring atoms and on the same side as C(5) should read The angle between the base and the ribose planes is 55". C(3') of the ribose is displaced by more than 0.5 A from the plane of the remaining ring atoms and on the same side as C(5'). For (structure X X . . read (structure 20. . For analogous to X X read analogous to 20. For RFCOF read RFCOF. For R,S or R,Ge have been interpreted read R,Si or R,Ge For (P309F)- read (P309F)4-. For FPO,- read FP0,2-. For SbF40S03F read SbF,SO,F. For M. N. Bucklish read M. N. Bukhsh. have been interpretedz0'. For a-lithio-organoalkane read a-lithio-organoalane. For opposite read same. brackets. Insert Me at C-5. Add Katsumi Kotera and YuzoNakagawa. For chained read chain. For have been reported to read have been reported of. For diastereoisomers were read diastereoisomers are. For asopressin read vasopressin. Transfer formula to page 646. Transfer formula to page 643. Page 803. Add Nakagawa Y. 507. * From foot of main text

ISSN:0069-3022    

DOI:10.1039/GR9676400381

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

AUTHOR INDEX

ISSN:0069-3022    

DOI:10.1039/GR9676400383

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

SUBJECT INDEX Abstraction of ions from solution 150. Acetylene complexes 353 354. Actinide elements 285. Activated alkyl halides dehydrohalogenations of 114, table of 113. Activated molecule reactions 112, activation energies of 1 15. photochemically- 116. Activation energies of activated molecule re-Addition reactions atomic 75, actions 115. kinetics of 83 84, mechanisms of 75, table of 76 77 86 87. table of 117. activation energies of 104, with unsaturated compounds table of, Adsorbed species infrared spectroscopy of 202, Adsorption at solid-liquid interfaces 150. Adsorption from liquid mixtures 152. Adsorption isotherm for liquids on a solid Adsorption of gases in micropores 162, molecule-molecule 1 16 1 18, radical 98, 99 100. spectra of 168.surface 15 1, on carbons 165, on oxides 163, on solids 161, on zeolites 167. structure 161. Adsorption properties dependence on surface Aerosols particle size distribution in 176, Alkali metals 22 I. Alkylcobalt chelates 345. Alkyl halides dehydrohalogenations of ; L C I I -vated 114, table of 113. size distribution in 177. mechanisms of dehydrohalogenations. 107. Ally1 complexes reaction with carbon monoxide. n-Ally1 complexes proton n.m.r. spectra of, Allylmanganese complexes 349. Aluminium hydride chemistry of 248. Aluminium-nitrogen ring compounds 247. Ammonia liquid solutions 261. Ammonia liquid,-sodium solutions 221. 109. 350. 348. organo-,compounds 245 246. Anomalies in vibration rotation spectra 200. Antimony compounds 269,270.Antimony-nitrogen ring compounds 263. Aqueous cobalt (111) solutions 297. Aqueous solutions vibrational characteristics of, Arene complexes 358 359. Aromatic hydrocarbons relative electron affinities of 16 17. Aromatic molecules electronic spectra of 2 1 1. Aromatic sulphur compounds 274. Arsenic compounds 268 269. Atomic addition reactions, 196. kinetics of 83 84, mechanisms of 75, tables of 76 77 86 87. Atomics reactions gaseous kinetics of 73. Atomic recombination reactions, mechanisms of 74, rate constants of 75, table of 80 81. Atomic recombinations theoretical approach Atomic transfer reactions, hydrogen abstraction in 88 90, kinetics of 85 89 90, rate constants of 85, table of 78 79. to 121. Average potential model of liquid mixtures 68.Azulene complexes structures of 361. Barriers to internal rotation 21. Beryllium compounds 222-225. Bimolecular reactions theoretical approach to, Binary liquid mixtures surface tension of 139. Biradical reactions of methylene 118-120. Bismuth compounds 270. Black lipid membranes 135. Bomb calorimetry fluorine- 5. 7. o-Bonded fluorocarbon complexes 346 347. o-Bonded organometallic compounds secon-dary interactions in 343 344. cr-Bonded phenylethynyl derivatives of transi-tion metals 343. Bonding in boron compounds 226. Borane adducts 227 228, 123, rotating- 5. 7. anions 237 cations 232. Boranes synthesis of 226. Borates crystal chemistry of 243. Borazines synthesis of 242 412 Subject Index Borohydrides metal structure of 233.Boron compounds 225-245, Boron-nitrogen compounds 241. Boron-phosphorous compounds 263. Boron-sulphur compounds 244. Boron-transition metal compounds 229. Boronium cations 23 1. bonding in 226. Calculation of rate constants of complex systems, Calorimetry combustion 6. 38. dynamic differential 10. fluorine bomb 5 7. fluorine flame 5. reaction 9. rotating-bomb 5. 7. Carbanion salts crystal structures of 253. Carbaphosphaborane 236. Carbene derivatives of transition metals 343. Carbon compounds 252. Carbon disulphide reaction with transition-metal complexeb 353. Carbon monoxide reaction with ally1 complexes, 350. Carbons adsorption of gases on 165. Carbonyl halide complexes of the platinum Carbonyl halides 322-324.Carbonyls metal containing sulphur 340. i.r. spectra of 320. mononuclear kinetic and spectroscopic data for 319 320. polynuclear 32 1, structures of 321. Carboranes 230 238. optical activity of 239. synthesis of 226. Carbosilanes 254. Catalytic properties of transition-metal com-Charge-transfer complexes spectra of 195. Chelate complexes of platinum 299. Chelation exothermic heats of 1 1. Chemical structure of solid surfaces 153. Chemiluminescence reactions mechanism of, Chromium(II) stereochemistry of 290. Cluster compounds of molybdenum 291, metals 324. plexes 327. 209, of niobium 290. of rhenium 294. of tantalum 290. of tungsten 291. of emulsions rapid kinetics of 135. Coagulation in sols 171. Cobalt complexes reaction with ketenimines, 352 353.organo- compounds 344 345. Cobalt(u) complexes of 296, stereochemistry of 296. Cobalt(m) aqueous solutions of 297. Cobalt(1Ir) complexes oxidation by 366 367. Colloid coagulation similions in 173. Combination reactions radical 91. Combustion calorimetry 6. Complete neglect ofdifferential overlap approxi-mations of molecular orbital calculations, 30 31. Complete neglect of differential overlap method of molecular orbital calculations 29. Complexes containing metal-metal bonds 341, 342, far4.r. spectra of 342. magnetism in 318. of cobalt(Ii) 296. of tripositive iron 295. of polyenes. 350 352. Complexes electronic spectra of 316 317. x-Complexes of monoenes 350-352, Complex systems calcillation of rate constants Complexing of transition metal ions heats of 11.Concept of natural geminals 35. Configuration absolute of co-ordination com-Contact angle at solid-liquid interfaces 145. Contribution of dimers to physical properties Co-ordinated ligands reactions of 378, Co-ordination compounds absolute configura-of 38. of natural orbitals 35. pounds 313. hysteresis 147. of gases 60. tion of 313, laser Raman spectra of 190, stereochemistry of 313, stereospecific reactions of 31 4. Co-ordination of nitrile groups 331. Copper complexes 300. dipositive stereochemistry of 300. Correlation energy from Hartree-Fock equa-Critical surface tension 148. Crystal chemistry of borates 243. Crystals structure of gold trifluoride 301. Crystal structures of carbanion salts 253.Cyanide as ligand 309. Cyclic organosilicon compounds 254 255. Cyclobutadiene complexes 354. Cyclo-octadiene complexes 359-361. Cyclopentadiene complexes 354-358. Cyclosilazanes 256. tion 25. Dehydrohalogenations of activated alkyl halides, 114, table of. 113. of alkyl halides mechanisms of 107 109. Denaturation protein thermodynamics of 18. Detergent solutions 126. Determination of fluid structures 65. of virial coefficient of gases by Burnett method 57, differential method 58 solubility method 59, volume change method 59 Subject Index 41 3 Diatomic molecules electronic spectra of 205. Diborane 233. Differential calorimetry dynamic 10. Dimers contribution of to physical properties Diphenylfulvene complexes formation of 361.Dipositive copper stereochemistry of 300. of gases 60. iron octahedral complexes of 295. mercury 301. nickel stereochemistry of 298. palladium thermochemical properties of vanadium complexes 289. aqueous 299. Disproportionation reactions radical 91. Dissociation energies of inorganic fluordies 15. Double-layer repulsion in soap films 140. Dynamic differential calorimetry 10. Dynamic surface tension of water 138. Effect of solvent properties on solution rate 40. Electric double-layer in sols 174. Electrokinetic phenomena in sols,. 174. Electron affinities relative of aromatic hydro-Electron correlations and Hartree-Fock equa-carbons 16 17. tion 26. in wave-functions 23. of complexes 3 16 3 17. of diatomic molecules 205. of free radicals 21 1.of lanthanide compounds 285. of large molecules 210. of triatomic molecules 207. Electronic spectra of aromatic molecules 21 1. Electronic spectroscopy Stark effect in 21 3. Elimination reactions molecular 107, table of 108. hydrogen abstraction in 94 95, pyrolytic reactions in 110 11 1, table of 102 103. radical 110, Emulsions kinetics of rapid coagulation of 135. particle-size distribution in 136. phase-inversion temperature in 137. Energies strain in organic cyclic compounds 9. Energy of a system lower boundary of 34. Enthalpies of formation of key compounds in Entropy change with micelle formation 130. Equilibrium studies heats of formation from 13. E.s.r. measurements of vandium oxides 298. E.s.r. spectra of nitrosyls 329.Exothermic heats of chelation 1 1. thermochemistry 3. Fast reactions studied by flash photolysis 54-56, n.m.r. 51, pulse radiolysis 49, relaxation methods 53. Five-co-ordinated transition-metal complexes, Fixation of nitrogen by biological systems, 3 1 0-3 1 3. molecular nitrogen adducts in the 329. Flame calorimetry fluorine- 5. Flash photolysis studies of fast reactions 54-56. Flocculation mechanism of in sols 172. Fluids theory of Hypernetted chain approxi-Percus-Yevick approximation 66 67 69, mation 66 67, 70. Fluid structures determination of 65. Fluorides inorganic dissociation energies of, Fluorine bomb calorimetry 5 7. Fluorocarbon complexes o-bonded 346 347. Fluorocarbon-hydrocarbon mixtures non-Force constants in vibrational spectra 196.Free-energy changes with wetting 147. Free radicals electronic spectra of 21 1. Fulvene diphenyl- formation of complexes of, 15. flame calorimetry 5. ideality of 71. 361. Gallium compounds 249-252. Gallium-nitrogen ring compounds 250. Gaseous adsorption in micropores 162, organo- compounds 250,25 1. on carbons 165, on oxides 163, on solids 161, on zeolites 167. Gaseous atomic reactions kinetics of 73. Gases contribution of dimers to physical proper-determination of virial coefficient of by ties of 60. Burnett method 57, differential method 58, solubility method 59, volume change method 59. intermolecular forces in 57. thermal diffusion factor of measurement of, 62. Geminals natural concept of 35. Germanium compounds preparation of 257 Gold complexes 301.Gold trifluoride crystal structure of 301. Grignard reagents 224. Group theory of non-rigid molecules 34. Group IV-transition metal complexes 333 334. Hafnium compounds 288,289. Halogen azides 263. Halogen charge-transfer species 280. Halogen-oxygen compounds 271. Halogenobismuth compounds 270. Hartree-Fock calculations and electrons correla-Heats of chelation exothermic 1 1. derivatives heats of decomposition of 9 10. tions 26. of complexing of transition metal ions 1 1. of decomposition of halogen derivatives 9, of formation from equilibrium studies 13. 10 414 Subject Index Heats of chelation-contd. Heptapositive technetium solutions 293. Hexapositive molybdenum complexes 292. Hydrocarbons aromatic relative electron Hydrogen abstraction in atomic transler re-of wetting 149.tungsten complexes 292. affinities of 16 17. actions 90. table of 88. table of 95. in radical transfer reactions 94, bridging in transition-metal hydrides 325. exchange in pentaborane-9 235. isotope effects on solution reactions 45-49. Hydrogen-bonded systems structure of from Hydrophobic interactions 144. Hypernetted chain approximation theory 01' spectroscopy 195. fluids 66 67. Indium compounds 249-252. Infrared spectra intensities in solids 201. Infrared spectroscopy of adsorbed species. 202. Initial spreading coefficients of lower-boiling Initial spreading pressures of lower-boiling Inorganic azides 302. Insoluble monolayers 142. Interaction potentials relation of gas data and Interatomic forces 3 1.Interfacial tension measurement of 133. Interhalogen charge-transfer species 280. Intermolecular forces in gases 57. Intermolecular reactions 379 380. Internal rotation barriers to 21. Ionic strength dependence of micellar weight on, Ions abstraction of from solution 150. Iridium complexes 297. Iron complexes reaction with ketenimines 352, organo- compounds 250,25 1. structure determination by 192. hydrocarbons on water 132. hydrocarbons on water 132. fluorides dissociation energies of 15. permeation of gases through. 141. solid-state data 61. perturbation-theory approach to 31 32 33. compounds 28 1. 128. 353. dipositive octahedral complexes of 295. tripositive complexes of 295. Isomerisations molecular 106, table of 105.Isonitrile complexes 330 331. Isotope effects on solutions reactions 45-49. Isotopic substitution effects of on vapour prcz~ures of Iquids 64. Ketenimines reaction with cobalt and iron complexes 352 353. P-Keto-amine complexes 304. fi-Keto-enolate complexes 303. Key compounds in thermochemistry enthalpies Kinetic data for mononuclear carbonyls 319, Kinetics of atomic addition reactions 83 84. of atomic transfer reactions 85 89 90. of gaseous atomic reactions 73. of rapid coagulation of emulsions 135. of solution reactions mathematical aspects of, of formation of 3. 320. 3 7. Langmuir-Blodgett monolayers 143. Lanthanide compounds electronic spectra of, 285. hydroxides 285. Large molecules electronic spectra of 210.Laser Raman spectra of co-ordination compounds 190. of liquids 189. of solids 189. Laser Raman spectroscopy 189. Lead compounds 260. Ligand-field strengths of quadri- and sexi-dentate ligands spectroscopic study of 305. Ligands 302-3 10. Liquid ammonia-sodium solutions 221. Liquid ammonia solutions 261. Liquid-liquid interfaces 132, multidentate 304. mobility at 133, molecular interactions at 133. specific adsorption at 134. 68. Liquid mixtures averages potential model of, Liquid random-packed spheres model of 67. Liquid-vapour interface 137. Liquids effects of isotopic substitution on vapour pressures of 64. Lithium halides 222. Lower boundary of the energy of a system 34. laser Raman spectra of 189. organo- compounds 222.Magnetism in complexes 318. 'Manganese complexes allyl- 349. tripoyitive complcxc\. 293. Mathematical aspects of the kinetics of solution Measurement of interfacial tension 133. thermal diffusion factor of gases 62. Mechanisms of atomic addition reactions 75. of atomic recombination reactions 74. of chemiluminescence reactions 209. of dehydrohalogentations of alkyl halides 107, reactions 37. 109. Ilembranes black lipid 135. Metal borohydrides structure of 233. carbonyls containing sulphur 340, 'cluster' compounds structures of 342. i.r. spectra of 320 Subject Index 415 Metal-metal bonds complexes containing 341, 342, far4.r. spectra of 342. Methylene biradical reactions of 118-120. Micellar weight dependence on ionic strength, Micelle formation 125, 128.entropy change with 130. thermodynamic parameters of 126. Micropores adsorption of gases in 162. Microwave double-resonance 186. Microwave spectra of p-block elements 183, of radicals 182, of small molecules 182, results table of 184 185. Microwave spectroscopy rotational relaxation. in 186. structure determination by 181. Mobility at liquid-liquid interfaces 133. Molecular eliminations 107, table of 108. interactions at liquid-liquid interfaces 133. isomerisations 106, nitrogen adducts 328 329. nitrogen adducts in the fixation of nitrogen by oxygen as ligand 332. table of 105. biological systems 329. Molecular orbital calculations semi-empirical, complete neglect of differential overlap complete neglect of differential overlap Molecule-molecule addition reactions 116 118, 28, method 29.approximations 30 31. table of 117. table of 117. transfer reactions 116 118. Molecules non-rigid group theory of 34. Molybdenum cluster compounds of 291. halides 291. hexapositive complexes 292. tetrapositive complexes 292. Monolayers insoluble 142. Langmuir-Blodgett 143. permeation of gases through 141. Mononuclear carbonyls kinetic and spectro-Multidentate ligands 304. scopic data for 319 320. Natural geminals concept of 35. orbitals concepts of 35. Nature of n sulphur-nitrogen bond 276. Nickel complexes 298 299. dipositive stereochemistry of 298. Nickel(11) complexes reaction of phosphine with, 339,340. Niobium cluster compounds of 290 compounds 290.Nitrile complexes 330 331. groups co-ordination of 331, Nitrogen compounds 261-263. fluorides as fluorinating agents 262. thermochemistry of 262. molecular adducts 328 329. Nitrogen-aluminium ring compounds 247. Nitrogen-antimony ring compounds 263. Nitrogen-boron compounds 241. Nitrogen-gallium ring compounds 250. Nitrogen-phosphorus compounds 263. Nitrogen-transition metal carbonyl complexes, Nitrosyls es.r. spectra of 329, N.m.r. studies of fast reactions 51. Noble gases compounds of 220. Non-ideality of fluorocarbon-hydrocarbon mix-Non-rigid molecules group theory of 34. Nucleophilic attack reduction by 368. 335. reactions of 330. tures 71. of metal carbonyls 320. Octahedral complexes of dipositive iron 295. substitution reactions of 368-375.Optical activity of carboranes 239, of phosphorus compounds 263. Orbital calculations molecular semi-empirical, complete neglect of differential overlap complete neglect of differential overlap 28. method 29, approximations 30 31. Orbitals natural concept of 35. Organoaluminium compounds 245-246. Organo-cobalt compounds structure of 344, Organodiphosphines as ligands 337. Organogallium compounds 250,25 I . Organoindium compounds 250,251. Organolithium compounds 222. Organometallic compounds a-bonded sccon-345. dary interactions in 343 344. substitution reactions of 376-378. Organophosphines as ligands 336. Organoplatinum compounds 345 346. Organosilicon compounds cyclic 254 255. Organothallium compounds 250 251.Oscillatory reaction systems 39. Osmium halides 296. Oxidation by cobalt(II1) complexes 366 367. Oxides adsorption of gases on 163. Oxygen-halogen compounds 27 1. Oxygen molecular as a ligand 332. Palladium dipositive thermochemical proper-Particle size distribution in aerosols 176. ties of aqueous 299. in emulsions 136. of sols 169. p-Block elements microwave spectra of 183. Pentaborane-9 hydrogen exchange in 235 41 6 Subject Index Percus-Yevick approximation theory of fluids, Permeation of gases through insoluble mono-Peroxide as ligand 308. Perturbation-theory approach to interatomic forces 3 1-33. Pervanadyl ion spectral evidence for 290. Phase-inversion temperature in emulsions 137. Phenylethynyl o-bonded derivatives of transi-tion metals 343.Phosphaborane 236. Phosphine reaction of with nickel(I1) complexes, Phosphorus compounds 263-268. 66 67 69 70. layers 141. 339 340. optically active 263. halides 264. oxides 265. Phosphorus-boron compounds 263. Phosphorus-nitrogen compounds 263. Photochemically activated molecular reactions, Photoelectron spectroscopy 2 14. Photolysis flash studiesoffast reactions 54-56. Physical properties of gases contribution of Physical structure of solid surfaces 157. Platinum chelate complexes of 299. metals carbonyl halide complexes of the 324. organo- compounds 345 346. Polyatomic molecules Rydberg states of 209. Polymers vibrational spectra of 202. Polynuclear carbonyls 321. structures of 32 1. Polyphosphates 265. Polyphosphines 263 264.Polysilanes 254. Pore-size distribution in solids 157. Potentials interaction relation of gas data and Protactinium halides 286. Protein denaturation thermodynamics of 18 Proton n.m.r. spectra of rr-ally1 complexes 348. Pulse radiolysis study of fast reactions 49. Quadridentate ligands spectroscopic study of 116. dimers to 60. solid state data 61. ligand-field strengths of 305. Radical additions 98, activation energies of 104, to unsaturated compounds table of 99,100. combination reactions 91. disproportionation reactions 91. elimination reactions table of 102 103. transfer reactions 94, hydrogen abstraction in 94 95, transition states in 96 97. Radicals microwave spectra of 182. Radiolysis pulse studies of fast reactions 49.Raman spectroscopy structure determination Random-packed spheres model of a liquid 67. by 192. Rare-earth elements compounds of 284, high co-ordination numbers of 284. Rate constants of atom-molecule reactions. tables of 76 77 78 79. atomic recombination reactions 75. atomic transfer reactions 85, complex systems calculation of 38. Reaction calorimetry 9. Reaction of ally1 complexes with carbon mon-of cobalt complexes with ketenimines 352,353. of iron complexes with ketenimines 352,353. ofphosphine with nickel(rI)complexes 339,340. of transition-metal complexes with carbon di-oxide 350. sulphide 353. Reaction systems oscillatory 39. Reactions fast studied by-pulse radiolysis 49. n.m.r. 51, relaxation methods 53, flash photolysis 54-56.Recombination reactions atomic mechanisms of 74, rate constants of 75, table of 80 81, theoretical approach to 121. Redox reactions 365-368. Reduction by nucleophilic attack 368. Relative electron affinities of aromatic hydro-Relaxation studies of fast reactions 53. Rhenium cluster compounds of 294. Rhodium complexes 296,297. carbons 16 17. role of solvation in solution reactions 41. of the solvent in solution reactions 39. Rotating-bomb calorimetry 5 7. Rotation internal barriers to 21. Rotational relaxation in microwave spectro-Ruthenium halides 296. Rydberg states of polyatomic molecules 209. scopy 186. Schiff bases 304. Secondary interactions in a-bonded organo-Selenium compounds 277-279. metallic compounds 343 344. halides structures of solid 278.structure of 277. Semi-empirical molecular orbital calculations, Sexidentate ligands spectroscopic study of Silicon compounds 253-257. Silver iodide complexes 301. Similions in colloid coagulation 173. Size distribution in aerosols 177. Small molecules microwave spectra of 182. 28. ligand-field strengths of 305. organo- cyclic compounds 254 255. vibrational spectra of 196, table of 197 198. Soap films double layer repulsion in 140. solutions 126 Subject Index 41 7 Sodium-liquid ammonia solutions 22 1. Solid-liquid interfaces 143. adsorption at 150. contact angle at 145, interfacial energies 144. Solid selenium halides structures of 278. Solid surfaces chemical structure of 153. physical structure of 157. study of 155.Solids adsorption of gases on 161. infrared spectral intensities in 201. laser Raman spectra of 189. pore-size distribution in 157. surface area of 159. surface energy of 160. Sols coagulation in I I I. electric double-layer in 174. e1ectrokhetk phenomena in 174. mechanism of flocculation in 172. particle size 169. stability 170. reactions isotope effects on 4 5 4 9 . role of solvation in 41. role of the solvent in 39. constants 43,44. Solution rate effect of solvent properties on 40. kinetics of mathematid aspects of 37. Solvation information from thermodynamic role of in solution reactions 41. Solvent in solution reactions role of 39. properties effect of. on solution rate 40. Specific adsorption at liquid-liquid interfaces, Spectra electronic of aromatic molecules 21 1.134. of complexes 316 317. of diatomic molecules 205. of free radicals 21 1. of lanthanide compounds 285. of large molecules 210. of triatomic molecules 207. e.s.r. of nitrosyls 329. i.r. intensities in solids 201. of metal carbonyls 320. microwave of p-block elements 183. of radicals 182. of small molecules 182. results table of 184 185. n.m.r. studies of tast reactions 51. of adsorbed species 168. of charge-transfer complexes 195. Spectral evidence for pervanadyl ion 290. Spectroscopic data for mononyclear carbonyls, study of ligand-field strengths of quadri- and Spectroscopy infrared structure determination 319 320. and sexi-dentate ligands 305. by 192. microwave rotational relaxation in 186, structure determination by 18 1.Raman structure determination by 192. structure of hydrogen-bonded systems from, 195. Square-planar complexes substitution reactions of 375 376. Stability of sols 170. Stark effect in electronic spectroscopy 213. Stereochemistry of chromium(rI) 290. cobalt( n) 296. co-ordination compounds 313. dipositive copper 300. dipositive nickel 298. Stereospecific reactions of co-ordination com-Strain energies in organic cyclic compounds 9. Structures chemical of solid surfaces 153. determination by infrared spectroscopy 192. by microwave spectroscopy 181. by Raman spectroscopy 192. pounds 314. of fluids determination of 65. of hydrogen-bonded systems from spectro-of metal borohydrides 233. of metal ‘cluster’ compounds 342.of selenium 277, of tin fluoride derivatives 258. of transition-metal hydrides 325. physical of sotid surfaces 157. scopy 195. solid halides of 278. Substitution reactions of octahedral complexes, 368-375. organometallic compounds 376-378. of square-planar complexes 375 376. of tetrahedral compounds 375. Sulphur-boron compounds 244. Sulphur compounds 272-277, Sulphur-containing metal carbonyls 340. IC Sulphur-nitrogen bond nature of 276. Surface area of solids 159. energy of solids 160, structure dependence of adsorption proper-ties on 161. tension critical 148. aromatic 274. dynamic of water 138. of binary liquid mixtures 139. Synthesis of boranes 226. borazines 242. carboranes 226. in 315 316. Systems of biological interest transition metals Tantalum cluster compounds of 290.compounds 290. oxides 290. Technetium hetapositive solutions 293. Tellurium compounds 279. Tetraborane 234. Tetrahedral compounds substitution reactions of 375. Tetrapositive molybdenum complexes 292. Thallium compounds 249-252. tungsten complexes 292. organo- compounds 250,25 1 418 Subjec Theoretical approach to atomic recombina-tions 121, bimolecular reactions 123, unimolecular reactions 122. Theory of fluids Hypernetted chain approxi-Percus-Yevick approximation 66 67 69 70. Thermal diffusion factor of gases measurement Thermochemical properties of aqueous diposi-Thermochemistry of nitrogen fluorides 262. Thermodynamic constants information on sol-mation 66 67.of 62. tive palladium 299. vation from 43,44. parameters of micelle formation 126. Thermodynamics of protein denaturation 18. Thickness of wetting films 148. Thiophosphates 266. Tin complexes 259. compounds 258. fluoride derivatives structures of 258. tripositive 288. Titanium compounds 287. Titanyl compounds 287. Transfer reactions atomic hydrogen abstrac-tions in 88,90 kinetics of 85 89 90, rate constants of 85. table of 78 79. table of 117. molecule-molecule 1 16 1 18, radical hydrogen abstraction in 94 95, transition states in 96,97. Transition-metal complexes catalytic properties of 327. five co-ordinated 310-313. reaction with carbon disulphide 353. hydrogen bridging in 325. structure of 325. ions heats of complexing of 1 1.hydrides, Transition metal-boron compounds 229. Transition metal-Group IV complexes 333,334. Transition metal-nitrogen carbonyl complexes, Transition metals o-bonded phenylethynyl de-335. rivatives of 343. carbene derivatives of 343. in systems of biological interest 315,316. Index Transition states in radical transfer reactions, Triatomic molecules electronic spectra of 207. Trifluorophosphine complexes 338. Tripositive iron complexes of 295. 96,97. manganese complexes 293. titanium 288. halides 291. hexapositive complexes 292. tetrapositive complexes 292. Tungsten duster compounds of 291. Unimolecular reactions theoretical approach to, Univalent zinc ion 301. 122. Vanadium compounds 289,290. dipositive complexes 289. oxides e.s.r. measurement of 289. Vanadyl complexes 289. Vapour-liquid interface 137. Vapour pressures of liquids effects of isotopic substitution on 64. Vibration rotation spectra 199, Vibrational characteristics of aqueous solutions, Vibrational spectra force constants in 196. anomalies in 200. 196. of polymers 202. of small molecules 196, table of 197 198. Virial coefficient of gases determination of by Burnett method 57, differential method 58, solubility method 59, volume change method 59. Water dynamic surface tension of 138. Wave-functions electron correlations in 23. Wetting free-energy changes with 147, heats of 149, in capillary systems 147. Wetting films thickness of 148. Zeolites adsorption of gases on 167. Zinc univant ion 301. Zirconium compounds 288,289

ISSN:0069-3022    

DOI:10.1039/GR9676400411

出版商:RSC    

年代:1967

数据来源: RSC