摘要:
J . CHEM. SOC. DALTON TRANS. 1994 2367Isomerism in Bis(diethylenetriamine)nickel(ll) Thiocyanate:Synthesis, Solid-state Interconversion and X- RayCrystallographic Study of sym-fac and mer Isomers tAlok K. Mukherjee,a Subratanath Koner,b Ashutosh Ghosh,b Nirmalendu Ray Chaudhuri,*TbMonika MukherjeeC and Alan J. Welchda Department of Pb ysics, Jadavpur University, Calcutta 700 032, lndiaCalcutta 700 032, IndiaCalcutta 700 032, IndiaDepartment of Inorganic Chemistry, Indian Association for the Cultivation of Science,Department of Solid State Physics, lndian Association for the Cultivation of Science,Department of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, UKBis(diethylenetriamine)nickel(tl) thiocyanate has been found to undergo a phase transition (1 62-1 80 "C,AH = 29.4 kJ mol-') involving a low-temperature ordered system (sym-fac isomer 1) and a high-temperature disordered system (mer isomer 2).Both isomers have been synthesised and characterizedby X-ray crystallography. Isomer 2 is metastable and reverts to 1 in the presence of a humid atmosphere(relative humidity ca. 60% or more) as heterogeneous catalyst. Isomer 1 crystallizes in the triclinic system,space group P i , with a = 7.240(2), b = 8.225(3). c = 8.766(3) A, O! = 63.27(2), p = 74.07(4), y =65.56(2)", Z = 1, R = 0.024. In the cationic unit, the ligand geometry around nickel(1t) is nearlyoctahedral. Two chelating tridentate diethylenetriamine (dien) molecules with terminal amino groupsin cis and secondary amino groups ic trans position define the sym-fac geometry.Isomer 2 crystallizesin the cubic system, space group F43m. with a = b = c = 12.373(3) A, Z = 4, R = 0.1 12. The cation[Ni(dien),J2+ is three-fold disordered about the [ l l I ] direction and the two tridentate dien moleculesare co -ordi nated meridiona Ily.Thermally induced solid-state geometrical isomerism in bis-(diamine) complexes of first-row transition metals is of greatinterest and has been studied by several workers.'-4 Howeverno such isomerism has been reported for bis(tridentate ligand)complexes.The bis complexes of the tridentate ligand diethylenetriamine(dien) can exist in three geometrical isomers: meridional (mer),symmetrical facial (sym-fuc) and unsymmetrical facial (unsym-fcc). The isolation and characterization of these isomers for first-row transition metals are well documented.' The equilibriumdistribution in solution and molecular-mechanics studies -9show that the difference in energy among them is only a fewkJ mol '.Therefore, the possibility of thermally inducedsolid-state transformation of these isomers cannot be ruledout." To investigate this, attempts have been made in thislaboratory for several Ni"(dien), complexes sf but none ofthem except the present one is found to undergo such isomeri-zation.Here we report the first ever example of such isomerizationin sym-fuc-bis(diethylenetriamine)nickel(n) thiocyanate whichon heating in the solid state transforms into its mer isomer.The latter has also been synthesised from solution. Single-crystal X-ray analyses of both the sym-fac and rner isomershave been performed.Experiment a 1All the chemicals used were AR grade and high-puritydiethylenetriamine was obtained from Fluka and distilledbefore use. Analyses (C, H and N) were made by a 240 Perkin-t SuppLernentarq data mailable: see Instructions for Authors, J.Chem.Soc., Dalton Trans., 1994, Issue 1, ppl. xxiii-xxviii.Non-SI unit emploved: pB % 9.27 x J T-'.Elmer elemental analyser. Infrared (in KBr) and electronicspectra (in Nujol) were recorded on Perkin-Elmer 783 andPhilips Analytical SP8-150 spectrophotometers, respectively.The effective magnetic moments were evaluated from magneticsusceptibility measurements with an EG and G PAR 155vi brating-sample magnetometer. X-Ray powder diffractionpatterns were recorded by a Philips XRD diffractometer (PW1730/1710) at 25 "C (relative humidity 30%) using Cu-Karadiation. The thermally induced solid-state transformationwas investigated with a Perkin-Elmer DSC-2 differentialscanning calorimeter and a Shimadzu DT-30 thermal analyser.Indium metal was used as calibrant for the evaluation ofenthalpy changes.Preparations.-sym-fac-[Ni(dien),] [SCN], 1.This complexwas prepared by addition of dien (2-3 mmol) to a solution ofnickel(r1) thiocyanate (1 mmol) dissolved in ethanol-water (9 : 1,10 cm'). Shiny pink crystals separated on stirring the resultingmixture for 2-3 min. These were filtered off, washed withethanol and dried in a desiccator (70% yield) (Found: C, 31.3;H, 6.9; N, 29.2; Ni, 15.1.CloH,6N,NiS2 requires C, 31.5;H, 6.8; N, 29.4; Ni, 15.4%). UV/VIS: h,,, 518 and 330 nm.perf 3. I pB. Recrystallization from methanol yielded pinkrhombic crystals suitable for X-ray analysis.mer-[Ni(dien),][SCN], 2. Diethylenetriamine (2-3 mmol)was added to a solution of nickel(1r) thiocyanate ( 1 mmol)dissolved in methanol (10 cm'). The resulting mixture was setaside without stirring at room temperature. After 4-5 dprismatic crystals appeared and were filtered off (40% yield)(Found: C, 31.4; H, 6.7; N, 29.5; Ni, 15.3. C,,H,,N,NiS,requires C, 31.5; H, 6.8; N, 29.4; Ni, 15.4%). UV/VIS: A, 520and 330 nm. perf 3.1 pB. Complex 2 was found to be unstableand reverted to 1 on keeping in a humid atmosphere (seeResults and Discussion), thus making extremely difficultcrystallographic data collection.Therefore, the crystal of 2 use2368 J. CHEM. SOC. DALTON TRANS. 1994for X-ray intensity data collection was coated with anamorphous resin immediately after isolation.X-Ray Data Collection, Structure Determination, and Refine-ment.-A suitable single crystal of complex 1 was mountedon a glass fibre using low-temperature adhesive. Diffractionmeasurements were made at 185 K with an Enraf-NoniusCAD-4 diffractometer equipped with a low-temperature device.Unit-cell dimensions were determined from the angular settingsof 25 randomly selected reflections. Intensity data were collectedby 0-28 scans and corrected for Lorentz-polarization andabsorption ' factors.The structure was solved by the heavy-atom method and refined by full-matrix least squares basedon F. The hydrogen atoms were located by Fourier-differencesyntheses. The final refinement with anisotropic thermalparameters for all non-hydrogen atoms (hydrogen atoms weretreated isotropically) converged to R = 0.024. Unit weightswere assigned throughout. The final difference map showedmaximum and minimum peak heights of + 0.47 and - 0.3 e A-3respectively. The crystal data are listed in Table 1 and atomiccoordinates in Table 2.Indexing of the X-ray powder pattern of complex 2 (h, k , 1either all odd or all even) revealed a face-centred cubic system.After several unsuccessful attempts, the single-crystal diffractiondata collection was finally performed on a Nicolet R3m/Vautomated diffractometer using graphite-monochromated Mo-Ka radiation (1 = 0.71073 A).Summaries of the crystal dataand data collection parameters are listed in Table 1. Unit-celldimensions were obtained by least-squares refinement of theangular settings of 15 reflections having 28 10-25 '. The datawere corrected as for 1. Systematic absences indicated possiblespace groups F23, Fm3, F432, Fm3m and Fa3m of which thelatter was confirmed by a successful structure solution. Owingto the remarkable disorder problem, a straightforward structuresolution of 2 by routine use of the program package MULTAN87 12a or SHELX 86 12' proved impossible. The structure wassolved by a meticulous interpretation of the apparently flatPatterson map coupled with judicious symmetry considerations.Since the face-centred cubic cell contained four wi(dien),l2 -+ cations and eight SCN- anions it was logical to assume that theNi atoms would occupy one of the four sets of 33m symmetrysites of the space group Fa3m.Positioning the Ni atom at $, $, +and considering the highest non-origin peak in the Pattersonmap at 0.315, 0.315, 0.315 to be due to the Ni-S interatomicvector (peaks due to Ni Ni interactions coincided with theface centring) the coordinates of the S atom of one of the anionswere obtained. The S atom of the remaining anion and the non-hydrogen atoms of the [Ni(dien),12 + cation, located fromsuccessive Fourier-difference maps, occupying different sym-metry sites were found to be disordered.The observed 2: 1occupancy factor ratio between the two N-atom sites withcoordinates x, x, z and $, +, x respectively indicated that theformer ones were primary nitrogens while the latter were thesecondary nitrogens of the chelating diamine. Satisfactoryrefinement of such a structure with high degree of disorderwas practically impossible. Isotropic constrained least-squaresrefinement with all observed data converged to R = 0.112.This high value could be attributed to the inability of locatingthe C and N atoms in the anions. A Fourier-difference mapcomputed at this stage contained maximum and minimumpeak heights of 0.59 and -0.44 e A-3 respectively indicatingthat the main structural features of 2, especially those of thecations, were correct.The atomic coordinates are listed inTable 3.Calculations were carried out with programs SHELX 76,' 2cSHELX 86, MULTAN 87 and PARST 12d on Vax ComputerStations at the University of York, and the Indian Associationfor the Cultivation of Science, Calcutta. Scattering factors andcorrections for anomalous scattering for Ni were taken fromref. 13. Selected bond distances and angles for 1 and 2 are givenin Tables 4 and 5.Table 1and mer-[Ni(dien),][SCN], 2Crystallographic data * for sym-fuc-~i(dien),][SCN], 1Crystal symmetry 3= groupblACIAa/ "PI"rlu pF(000)Dclg cm-3DmlgCrystal size/mmp1cm-lTIKRange 201"No. of reflectionsmeasuredCriterion for observeddataz[ I 2 no(1)]No. of observed dataRR'TriclinicPi-7.240(2)8.225(3)8.766(3)63.27(2)74.07(4)65.56(2)421.9(4)12021.501.480.4 x 0.3 x 0.213.3185269 13-60223220.0240.024CubicF43m12.373(3)12.373(3)12.373(3)9090901894(1)48081.341.370.3 x 0.15 x 0.1011.829 12083-50all data2080.1 120.1 12* Details in common: CloH2,N,NiS2; M 381.2; scan method -20.Table 2 Atomic coordinates with estimated standard deviations(e.s.d.s) in parentheses for sym-fac-[Ni(dien),][SCN], 1Atom X Y z00.1639(2)- 0.0 1 54( 2)- 0.2441 (2)- 0.3398(3)0.0574( 3)0.221 8(3)0.0451(3)- 0.1739(3)- 0.41 44(2)-0.5258(1)00.2748(2)0.0836(2)0.1238(2)0.3837(2)0.25 1 O(3)0.1056(3)0.1999(3)- 0.2066(3)- 0.2756(2)-0.3687(1)0- 0.0233(2)- 0.2455(2)-0.1467(2)- 0.153 l(3)- 0.20 12(3)- 0.2758(3)- 0.3695(2)- 0.3322(2)- 0.1985(2)- 0.2634( 1)Table 3 Atomic coordinates with e.s.d.s in parentheses for mer-pi(dien),][SCN], 2X0.250.567(2)0.163(3)0.365( 1)0.250.37 5( 3)0.3 1 7(3)Y0.250.567(2)0.773(7)0.365(1)0.250.375(3)0.317(3)Z0.250.567(2)0.163(3)0.278(6)0.4 14(20)0.40 1 (6)0.494(4)Occupancyfactor0.04170.04 170.041 70.16670.08330.16670.1667Additional material available from the Cambridge Crystallo-graphic Data Centre comprises H-atom coordinates, thermalparameters and remaining bond lengths and angles.Results and DiscussionStructure of sym-fac-[Ni(dien),][SCN], 1 .-The crystalstructure consists of discrete [Ni(dien),12 + cations and NCS -anions. With the Ni atom lying at a crystallographic inversioncentre, the asymmetric unit consists of one chelated triamineand one thiocyanate.An ORTEPI4 view with the atoJ. CHEM. SOC. DALTON TRANS. 1994 2369labelling and ring numbering scheme is shown in Fig. 1. TheNi-N bond distances range between 2.096 (1) and 2.134(1) A,consistent with similar systems. ' The nickel environment is asnearly octahedral as the ligand bite angles permit, comprisingsix nitrogen atoms from two tridentate dien molecules with theterminal amino groups in cis and secondary amino groups intrans position. Complex 1 is therefore the sym-fac geometricalisomer. The conformation of the chelate rings according to thering numbering scheme in Fig.1 is 16, h6. This conformer wasfound to exist in sym-fac-[Co(dien),]Br, l 6 and calculated topossess lower strain energy than any other conformer of thecobalt(I1r) system. However, as Ni" has M-N bond lengthssimilar to those of Co", the minimized strain energies ofthe nickel(r1) isomers should be very close to those of thecorresponding cobalt(r1) isomers. In syrn-fac-[C~(dien),]~ + the h6, h6 conformer has been calculated to have a strainenergy 3 kJ mol-' higher than that of the lowest-strain-energyconformer Ah, Ah. The less-favoured conformation may exist incrystals owing to intermolecular forces and the release of energyon lattice formation where the conformers differ in energy onlyby a few kJ mol-'.Weak hydrogen bonding between thenitrogen atom of thiocyanate and one of the primary aminogroups was observed "(3) N(4) 3.10, N(3)-H(N3B) 0.80,N(4)-H(N3B) 2.37 18,; N(4)-H(N3B)-N(3) 151'1.Structure of mer-[Ni(dien),][SCN], 2.-The crystal struc-ture consists of disordered Wi(dien),l2 + cations and SCN-anions. The asymmetric unit contains one Ni, two N, two Catoms of the cation and two SCN groups (anionic part), alllying on various special positions with adequate fractionaloccupancies. The nickel atom is surrounded by 18 (12 + 6symmetry-related sites of x, x, z and &, $, x types) nitrogenatom sites forming three groups of 4 + 2. Each group ofnitrogen atoms displays a distorted-octahedral geometry, theN-Ni-N angles ranging between 80( 1) and 180( 1)" respectively.The two tridentate dien molecules with both terminal andsecondary amino groups trans define complex 2 as a meridionalisomer.The corresponding N atoms of the three NiN, chromo-phores are related by transformations x, y , z - z , x, y --+y , z, x, leading to a three-fold disorder of the cation about the[ 1 1 13 direction. With such disordering the C,N positions couldobviously be ascertained with limited accuracy. This led to anindeterminacy of the chelate ring conformation. An ORTEPview of the cation (without disorder) is shown in Fig. 2. BondTable 4parentheses for sym-fac-[Ni(dien),][SCN], 1Selected bond distances (A) and angles (") with e.s.d.s inNi-N( 1) 2.134( 1) Ni-N(2) 2.1 10( 1 )Ni-N( 3) 2.096( 1) N(1)-C(1) 1.481(2)N(2)-C(2) 1.493(2) N(2)-C(3) 1.471(2)N(4)-C(5) 1.161(2)N(3)-C(4) 1.479(2) s-C(5) 1.647(2)N(1)-Ni-N(2) 81.2(1) N( I)-Ni-N(3) 92.6( 1)N(2)-Ni-N( 3) 82.1( 1) Ni-N(1)-C(1) 110.1(1)Ni-N(2)-C(2) 109.7(1) Ni-N(2)-C(3) 107.4( 1)Ni-N(3)-C(4) 110.6( 1) S-C(5)-N(4) 178.5(2)Table 5 Bond distances (A) and angles (") of the cation in mer-[Ni(dien),][SCN], 2 with e.s.d.s in parenthesesNi-N(I 1 ) 2.04( 2) Ni-N(21) 2.03( 2)C(I 1)-C(21) 1 .53( 8)N( 1 1 )-Ni-N(2 1 ) 80( 1 N(1 l)-Ni-N(13) 161(2)N(2 1)-Ni-N(22) 180( 1) Ni-N( 1 1)-C( 1 1) 106(2)N(l1)-C(I1) 1.53( 10) N(2 1 )-C(2 1) 1.53(5)Ni-N(2 1 )-C(2l) 1 30(2) N(ll)-C(ll)-C(21) 132(3)N(21)-C(21)-C(11) 91(3)distances and angles of the cation are listed in Table 5.Theobserved Ni-N bond distances are in agreement with those in 1and related systems.Thermal Isomerization.-Complex 1 on heating shows anendothermic phase transition (1 62-1 80; peak 168 "C) in thedifferential thermal analysis (DTA) curve, whereas the thermalgravimetric analysis (TGA) curve remains flat (Fig.3). Theenthalpy change of this irreversible transformation wasestimated to be 29.4 kJ mol-I by differential scanningcolorimetry (DSC). The colour of the species after the transitionseems to be more intense than that of the species before theFig. 1ring numbering schemeAn ORTEP view of complex 1 with the atom labelling andFig. 2 An ORTEP view of cation (without disorder) in complex 2 withthe atom labelling scheme\Endothermic- -2II I I I150 160 170 18077°CFig.3 The TG-DTA (weight taken = 10.89 mg) (a) and DSC (weighttaken = 4.3 mg) (b) curves for complex 2370 J. CHEM. SOC. DALTON TRANS. 1994transition. The IR spectra and X-ray powder diffractionpatterns (Figs. 4 and 5 ) of the former species differ appreciablyfrom those of 1 but are interestingly identical to those of 2.Therefore, it is assumed that mer-[Ni(dien),][NCS], 2 andthe species formed after the phase transition are identical, i.e.the fac isomer on heating isomerizes endothermally to themer isomer.Magnetic Moments and Electronic Spectra.-The magneticmoment and electronic spectrum of complex 1 are typical ofoctahedral nickel(1r) and those of 2 are very similar.IR Spectra.-Searle and House5e used IR spectroscopy tocharacterize three possible geometric isomers of [Cr(dien),13 + .Thefac isomers have a band at 780 cm-' which is absent for themer isomer.Complex 1 shows the characteristic intense peak ofa fac isomer at 780 cm-' (Fig. 4). Complex 2 shows an intensepeak at 890 cm-', a weak peak at 862 cm-l and a broad band atca. 1570 cm-' all of which are characteristics of a mer i s ~ m e r . ~ "Moreover the spectral pattern of 2 in the region 950-800 cm-.'is a replica of that of mer-[Ni(dien),]Cl,~H,O the structureof which has been determined by single-crystal X-ray crystal-lography." Therefore, it is reasonable to conclude that in 2the ligands are arranged meridionally. This was subsequentlyconfirmed by single-crystal X-ray analysis.Effect ofHumidity.-Complex 2 is metastable and on keepingin a humid atmosphere reverts to 1.Measurements of AH (byDSC) and X-ray powder diffraction patterns (Fig. 5 ) have beenused to study the rate of reversion and to characterize theproducts. The X-ray powder pattern of 2 shows fewer lines thanthat of 1. When 2 was kept in a humid atmosphere it showed allthe strong characteristic lines of 1 in addition to the originallines, and the intensities of the lines corresponding to 1increased while those of 2 decreased in the course of time.Finally the latter disappeared leaving only the lines of 1,indicating complete reversion 2 - 1. The rate of reversion isdependent on the relative humidity. To study this we used threeclosed vessels of constant humidity," ca.90, 60 and 30%, andthe results are shown in Table 6. It is clear that the higher is thehumidity the faster is the rate of reversion. This indicates theapparent involvement of a water molecule although neither 1nor 2 absorbs any water from the humid atmosphere. Therefore,the water molecule is acting as a heterogeneous catalyst.Kinetic Analysis.-The rate equation for the non-isothermalsolid-state reaction can be expressed 19,20 as in (1) where a is theIn [(da/dT)P] - In F(a) = In A - (E/RT) (1)fraction of the reaction after time t , F(a) is a function dependingon the reaction mechanism, is the linear heating rate, A is thepre-exponential factor, E the activation energy and R the gasconstant. In this study the rate of reaction [(da/dT)p] hasbeen directly determined from the DSC measurements.A plotof In [(da/dT)P] - In F(a) against T-' shows the best linearityover nearly the whole reaction range if F(a) is taken to be 1 - a(Fig. 6).19 The activation energy obtained from the plot isTable 6 Reversion of mer-[Ni(dien),][SCN], 2 to sym-fac-[Ni-(dien),][SCN], 1 at different relative humiditiesRelative Dayshumidity (%) exposed Reversion (%)90 14 9090 30 10060 14 260 30 530 30 0748 k 75 kJ mol-'. A possible explanation for the observedhigh activation energy in the present system compared to thatfor geometrical isomerism in bis(diamine) complexes 2o ( = 325kJ mol-') is as follows. In the latter case rearrangement of onlyone chelate ring is sufficient for cis trans isomerism,whereas for the proposed fa.I mer isomerization at leastone chelate ring of each dien molecule needs to be rearranged inWavenumber (cm-')Fig. 4 Infrared spectra for complexes 1 (&-) and 2 (- - - -)281"Fig. 5partially reverted product of 2, kept at 90% relative humidity for 5 dX-Ray powder patterns for (a) complex 1, ( b ) 2 and (c) the-1.5h -2.5LLI-n n Da = 0.14 . 52.23 2.24 2.25 2.26lo3 T-~IK-'Fig. 6 Plots of In [(da/dT)P] - In F(n) uersus T-'. Among the ninemodels *' of F(a) examined these three plots approach the best linearity.F(a) = (1 - a)" where n = 1 (O), (0) or (AJ. CHEM. SOC. DALTON TRANS. 1994 237 1the transition state. This indicates that the reaction occursthrough a bond-rupture mechanism.’ A similar mechanismhas been suggested for sym-fac FEZ? mer rearrangement of[Co(dien),13 + in solution.22The results of this work can be summarized as follows.(a) Bis(diethylenetriamine)nickel(~~) thiocyanate undergoes aphase transition involving a low-temperature ordered system(sym-fac isomer) and a high-temperature disordered system(mer isomer).( b ) The mer isomer can also be synthesisedfrom solution and is metastable. It reverts to the sym-fac isomerin a humid atmosphere (relative humidity ca. 60% or above)as heterogeneous catalyst. ( c ) The sym-fac ZII? mer isomeriz-ation for the dien system is reported here for the first time in thesolid state.AcknowledgementsWe thank Professor Siddhartha Ray, Department of SolidState Physics, Indian Association for the Cultivation of Sciencefor very enlightening discussions concerning the structure ofcomplex 2, and Professor A.Chakravorty for X-ray datacollection of 2 at the National Single Crystal DiffractometerFacility, Department of Inorganic Chemistry, Indian Associ-ation for the Cultivation of Science, Calcutta. Funding for thework described was provided by the Council of Scientific andIndustrial Research (New Delhi) Grants Scheme and isgratefully acknowledged.ReferencesI H. E. LeMay, jun., Inorg. Chem., 1971, 10, 1990; G. Wilkinson(Editor), Comprehensive Inorganic Chemistry, Pergamon, Oxford,1987, vol. 1, pp. 463473.2 S. Mitra, T. Yoshikuni, A. Uehara and R. Tsuchiya, Bull. Chem. SOC.Jpn., 1979,52,2569; R.Tsuchiya and A. Uehara, Thermochim. Ac-ta,198 1,50,93; R. Tsuchiya, A. Uehara and Y . Muramatsu, Bull. Chc.m.Suc. Jpn., 1982,55,3770; R. Tsuchiya, A. Uehara and T. Yoshikoni,Inorg. Chem., 1982,21, 590.Y . Ihara, Y. Fukuda and K. Sone, Bull. Chem. Soc. Jpn., 1986,59,1825; Y. Ihara, Y. Satake, Y. Fujimoto, H. Senda, M. Suzuki andA. Uehara, Bull. Chem. Soc. Jpn., 1991,64,2349.A. Ghosh, S. Koner and N. R. Chaudhuri, Thermochim. Acta, 1988,124,297; S. Koner, A. Ghosh and N. R. Chaudhuri, J. Chem. Soc.,Dalton Truns., 1990, 1563; Bull. Chem. Sue. Jpn., 1990,63, 2387.(u) H. H. Schmidtke and D. Garthoff, Inorg. Chim. Acta, 1968, 2,357; ( h ) N. F. Curtis and H. K. J. Powell, J. Chem. Soc. A , 1968,893;(c) F. R. Keene and G. H. Searle, Chem.Commun., 1968,893; ( d ) M.Dwyer and G. H. Searle, J. Chem. Soc., Chem. Commun., 1972,762;( e ) G. H. Searle and D. A. House, Aust. J. Chem., 1987, 40, 361and refs. therein; (f) S. Koner, A. Ghosh and N. R. Chaudhuri,Transition Met. Chem., 1988, 13, 291; 1990, 15, 394.6 F. R. Keene and G. H. Searle, Inorg. Chem., 1972, 11, 148;Y. Yoshikawa and K. Yamasaki, Bull. Chem. Sue. Jpn., 1972,45,179;F. R. Keene and G. H. Searle, Inorg. Chem., 1974,13,2173.7 M. D y e r and G. H. Searle, J. Chem. SOC., Chem. Commun., 1972,726.8 M. R. Snow, J. Am. Chem. Soc., 1970,92,6310; D. A. Buckingham,I. E. Maxwell, A. M. Sargeson and M. R. Snow, J. ilm. Chem. Soc.,1970,92,3617; A. M. Bond, T. W. Hambley and M. R. Snow, Inorg.Chem., 1985,24, 1920.9 Y .Yoshikawa, Bull. Chem. Sue. Jpn., 1976,49, 159.10 D. R. Bloomquist and R. D. Willett, Coord. Chem. Rev., 1982, 47,125.11 A. C. T. North, D. C. Philips and F. S. Mathews, Aczn Crystallogr.,Sect. A, 1968,24, 351.12 ( a ) T. Debaerdemaeker, G . Germain, P. Main, C. Tate andM. M. Woolfson, MULTAN 87, A System of Computer Programsfor the Automatic Solution of Crystal Structures from X-RayDiffraction Data, Universities of York and Louvain, 1987;( b ) G. M. Sheldrick, SHELXS 86, Program for Crystal StructureDetermination, University of Gottingen, 1986; ( c ) G . M. Sheldrick,SHELX 76, System of Crystallographic Computer Programs.University of Cambridge, 1976; ( d ) M. Nardelli, PARST, A Systemof Computer Programs for Calculating Molecular Parameters fromResults of Crystal Structure Analyses, University of Parma, 1982.13 International Tables for X-Ray Crysrallography, Kynoch Press,Birmingham, 1974, vol. 4.14 C. K. Johnson, ORTEP, A Fortran Thermal Ellipsoid Plot Programfor Crystal Structure Illustration, Report ORNL 3794, Oak RidgeNational Laboratory, Oak Ridge, TN, 1965.15 A. K. Mukherjee, M. Mukherjee, S. Ray, A. Ghosh andN. R. Chaudhuri, J. Chem. Soc., Dalton Trans., 1990, 2347;A. K. Mukherjee, M. Mukherjee, A. J. Welch, A. Ghosh, G. Deyand N. R. Chaudhuri, J. Chem. Soc., Dalton Trans., 1987, 997;K. 0. Joung, J. C. O’Connor, E. Sinn and R. L. Carlin. Inorg Chem.,1979, 18, 804; R. E. Cramer, W. V. Doorne and J. T. Huncke,Inorg. Chem., 1976, 15, 529.16 M. Kobayashi, F. Marumo and Y. Saito, Acta Crystullogr., Sect. B,1972, 28,470.17 P. Paoletti, S. Biazini and M. Cannas, Chem. Commun., 1969, 5 13.18 The Merck Index, Merck and Co., Rahway, NJ, 1976, p. MISC 71.19 C. H. Bamford and C . F. H. Tipper (Editors), Comprehensive20 Y. Matsuda, T. Matsuda, H. Kume and Y. Ihara, Thermochim. Acta,21 M. Corbella and J. Ribas, Znorg. Chem., 1987, 26, 3589 and refs.22 G. H. Searle, F. R. Keene and S. F. Lincoln, Inorg. Chem.. 1978,Chemical Kinetics, Elsevier, Amsterdam, 1980, vol. 22, p. 106.1989, 156, 137 and refs. therein.therein.17, 2362.Received 20th January 1994; Puper 4/00363
ISSN:1477-9226
DOI:10.1039/DT9940002367
出版商:RSC
年代:1994
数据来源: RSC