摘要:

J. CHEM. SOC. DALTON TRANS. 1988 63 5Reactivity of Cationic Molybdenum(l1) Complexes. Part 2.' ElectrochemicalReduction of the Eighteen-electron Complexes [ Mo( CO),(+C,Me,)L] i- [ L =Co, p-MeC,H,NC, or P(OMe),]. Crystal Structure of [Mo,(CO),(~~-C,M~,),] *Piero LeoniScuola Normale Superiore, Piazza dei Cavalieri, 7,56 100 Pisa, ItalyFabio Marchetti and Marco PasqualiDipartimento di Chimica e Chimica lndustriale dell' Universita, Via Risorgimento, 35, 561 00 Pisa, ItalyPiero ZanelloDipartimento di Chimica dell' Universita, Pian dei Mantellini, 44, 53 I00 Siena, ItalyThe 18-electron cationic complexes [Mo(CO),(q5-C,Me,)L] + [L = CO, p-MeC,H,NC, or P(OMe),]undergo, in dichloromethane solvent, a one-electron cathodic process, which gives rise to differentproducts depending upon the nature of L.Through an e.c.c. electrode mechanism, the irreversibleone-electron reduction of [ Mo(CO),(q5-C,Me,)] + and [Mo(CO),(q5-C,Me,) (p-MeC,H,NC)] +affords the d imer [ M o,( CO),( q5- C,M e,),] , whereas [ M o (CO) 3( q5- C,Me,) { P (0 Me) ,}I + leads to[ M 0, (CO) , ( q5- C,Me,) ,{ P (0 Me) ,},I. The dimer [ M o,( CO) , ( q5- C,M e,) ,] has been characterized by anX-ray structure determination. A preliminary electrochemical investigation on [Mo(CO) (q5-C,Me,) -(PhCrCPh),] + indicates that it can be reduced in two sequential one-electron quasi-reversiblesteps, [Mo(CO) (q5-C,Me,) (PhCSPh),] and [Mo(CO) (q5-C,Me,) (PhCrCPh)] - however beingstable only for short times (t+ z 50 s ) .In Part 1 we dealt with the chemical reduction of 18-electroncationic molybdenum(I1) complexes of general formula[Mo(CO),(q 5-C5Me5)L] +.The results obtained have shownthat the reduction occurs at the strongly electrophilic metal.We present here an electrochemical study of the reductionprocesses of the species [Mo(C0),(qs-C5Me5)L] + [L = CO(l), p-MeC,H,NC (2), or P(OMe), (3)] in the hope that acomparison between chemical and electrochemical reductionsmay provide further information on the reactivity of suchcomplexes. We note in addition that, despite the increasinginterest towards molybdenum cyclopentadienyl-carbonylcomplexes, their electrochemistry is almost ~nexplored.~.~Results and DiscussionElectrochemistry.-The cyclic voltammogram reported inFigure 1 shows that (l), in dichloromethane solution, undergoesone main reduction process.Controlled-potential coulometricexperiments performed at potentials just beyond the cathodicpeak A (working potential: - 1.0 V) led to the consumption ofone mole of electrons per mole of (1). Cyclic voltammetryperformed at scan rates varying from 0.02 V s-' to 50 V s-'indicated peak B, present in the reverse scan, to be attributableto the oxidation of fragmentation products of the one-electronreduced species rather than to direct reoxidation of the latter. Infact, the increase in scan rate results in peak B disappearing.Even at the highest scan rate (50 V s-I), no directly associatedreoxidation peak could be detected in the reverse scan aftertraversing peak A. Both the presence of the minor voltammetricresponses B and C as a consequence of the cathodic step and thechemical evidence discussed below indicate that the electro-chemical irreversibility of the one-electron reduction process isonly apparent, being attributable to fast chemical reactionscoupled to the charge transfer, rather than to any intrinsic* Bis[tricarbonyl(pentamethylcyclopentadienyl)molybdenum(~)].Supplementary data available: see Instructions for Authors, J.Chem.Soc., Dalton Trans., 1988, Issue 1, pp. xvii-xx.A10050X c .P50El VFigure 1. Cyclic voltammetric response recorded at a platinum elect-rode on a CH,CI, solution containing (1) (3.6 x mol dm-3) and[NBu,]BF, (0.1 mol dm-j). Scan rate 0.2 V s-li 30 n1 5 tFigure 2.Cyclic voltammetric response recorded at a platinum elect-rode on a CH,Cl, solution containing (2) (9.6 x lo4 mol dm-3) and[NBu,]BF, (0.1 mol dm-9. Scan rate 0.2 V s-636 J. CHEM. SOC. DALTON TRANS. 1988Table 1. Potential values (V) of the redox changes recorded in dichloromethane solutions of [ M o , ( C O ) ~ ( ~ ~ - C ~ H ~ ) , ] and [Mo,(CO),(q5-C5Me5),].Peak potentials obtained at a scan rate of 0.2 V ssl (CO ligands)MozL, Mo,L, + 2e- 2[MoL]- - Mo,L, - 2[MoL]+ + 2e - 2[MoL] - Mo,L, + 2e- 2[MoL]+ + 2e - Mo,L,[Mo2(C0)6(q 5-C5H 5)21 - 1.21 - 0.09 + 1.00 - 0.42[Mo2(C0)6(r15-C5Me5)21 - 1.58 - 0.22 +0.85 - 0.5 11005042 - .Y 0 .-50El VFigure 3. Cyclic voltammogram recorded at a platinum electrode on aCH,Cl, solution containing (3) (2.3 x le3 mol dm-3) and[NBu,]BF, (0.1 mol dm-3).Scan rate 0.2 V s-'aspect of the interaction between reactant molecule andelectrode surface.Figure 2 shows that a qualitatively similar cyclic voltam-metric behaviour holds for compound (2). In fact, apart fromthe different picture outlined by the reoxidation of short-livedintermediates arising from the reduction process, controlled-potential coulometry (working potential: - 1.2 V) indicatedthat in this case also the reduction process involves a one-electron step. Also in this case no anodic peak directlyassociated with the cathodic process could be detected in thereverse scan even at 50 V s-'. The solutions resulting fromexhaustive cathodic electrolyses of (1) and (2) were examined inorder to identify the electrogenerated products. In both cases,i.r.spectra in the terminal CO region displayed absorptions at2 010, 1960, 1935, 1902, 1 870, and 1740 cm-'. Evaporationof the solvent, followed by extraction of the residue with toluene,afforded the dimer [M02(Co),(?15-c5Me5)2], the X-raystructure of which was solved (see below).While the electrochemical reduction of [M0(c0),(q5-C,Me,)L]+ (L = CO or p-MeC,H,NC) allows isolation ofthe dimer [M0,(C0),(q5-C,Me,)~] in a pure form (ca. 60%yield), the literature method for the synthesis of [Mo,(CO),-(q ,-C,Me,),] is more laborious, chromatographic separationfrom [ Mo, (CO),(q -C , Me ,) 2] being necessary.,The unexpected presence in solution of the absorptions at2 010, 1960, 1870, and 1740 cm-', characteristic of[Mo(CO),(q5-C,Me,)] + and [Mo(CO),(q5-C,Me,)] -,, inaddition to those of the dimer (1 935 and 1902 cm-'),, wasunderstood through the following experiment.The dimer[Mo2(CO),(q ,-C,Me,),] was dissolved in dichloromethane inthe presence of an excess of [NBu,]BF,, used as supportingelectrolyte in the electrochemical experiments. The resulting i.r.Table 2. Peak potential values (V) for the one-electron reduction of[Mo(CO),(q5-C5Me,)L] + in dichloromethane solutionL EP* co - 0.73p-MeC,H,NC - 1.17P(OMe), - 1.31* At a scan rate of 0.2 V s-*.spectrum exhibited absorptions typical of [Mo2(CO),(q5-C,Me,)] -, indicating that the dimer undergoes a dispropor-tionation reaction. The photochemical disproportionation of[Mo2(CO),(q 5-C,H,),] is and has been reportedto occur in the presence of salts possessing a co-ordinatinganion,' as well as in the presence of a few Lewis Thedriving force for the reaction could be the achievement of an18-electron closed-shell configuration by the cationic moiety.In this respect our results are somewhat different in that thedisproportionation of the permethylated dimer is promoted by[NBuJBF,, which contains only a weakly co-ordinating anion.The electrochemical behaviour of [M0,(CO),(q5-C5H5)2]has recently been elucidated., In non-aqueous solvents itundergoes a two-electron oxidation as well as a two-electronreduction, both charge transfers being coupled to subsequentreactions.The compound [Mo,(CO),(q ,-C,Me,),] behaves inthe same manner.Table 1 briefly compares the redox potentialsof these steps for the two dimers, together with those of theproducts from the subsequent relevant chemical reactions. Asexpected the permethylated compound is more difficult toreduce and is more easily oxidized. In this light the ill-definedpeak D in Figure 1 could be attributed to the cathodic reductionof the electrogenerated [Mo2(CO),(q ,-C,Me,),].Figure 3 illustrates the cyclic voltammetric behaviour ofcompound (3). As in the previous cases, a single one-electronreduction process is displayed, which does not show directlyassociated reoxidation processes in the reverse scan, even atthe highest scan rate. The product resulting from exhaustiveelectrolysis was identified following the procedure reportedabove in the isolation of [MO,(CO),(~~-C~M~,)~]. In thiscase [Mo,(CO),(q5-C,Me,),(P(OMe),}2] was the recovereddimer, the identification being based on comparison of itsspectroscopic properties with those of an authentic sample (seeExperimental section).The result was not unexpected, sinceP(OMe), is a very effective ligand for co-ordination tomolybdenum in these system^.'^Table 2 summarizes the redox potentials for the reduction ofthe species (1)-(3). As expected, the greater the ability of L toincrease the electronic density on the metal, the more cathodicthe reduction potentials become.In summary, the overall electrode mechanism involved in thecathodic reduction of the species (1+(3) can be summarizedaccording to different e.c.c.mechanisms, equations (1) and (2).In the case of L = CO or p-MeC,H,NC mechanism (1) isfollowed, whereas for L = P(OMe), mechanism (2) holds. Theformation and the evolution of 19-electron intermediatesobtained by electrochemical reduction of 18-electron cationsC,Me,),l, [Mo(Co)3(~5-C5Me5>I +, and [Mo(CO)3(q 5 J. CHEM. SOC. DALTON TRANS. 1988 637-Y 17e17ehas recently been discussed for carbonylmanganese(r)derivatives. 'We also wish to report here the results of a preliminaryinvestigation on the cathodic behaviour of [Mo(CO)(q5-C,Me,)L,]+ (4) (L = PhCgPh). As shown in Figure 4, thealkyne derivative displays two sequential cathodic steps, withmarked features of reversibility. Step by step controlled-potential coulometric experiments at the potentials of the twopeaks indicated each of the two processes to involve one-electron per molecule.In addition, after exhaustive electrolyses,the species responsible for peaks C and D are no longer present.20 .aI- .-0t'-10.6I 11- I-2.00m I -l.OO " CI- x 10-DFigure 4. Cyclic voltammogram recorded at a platinum electrode on aCH,CI, solution containing (4) (1.03 x mol dm-3) and[NBu,]BF, (0.1 mol dm-3). Scan rate 0.2 V s-lBeyond any doubt these data indicate the occurrence of e.c. typecathodic processes, with the [Mo(CO)(q 5-C5Me,)L2] and[Mo(C0)(q5-C,Me,)L2] - species, electrogenerated in corre-spondence to the peaks A and B respectively, being unstable atlonger electrolysis times.Analysis of the cyclic voltammetric response A/D with thescan rate varying from 0.02 V s-' to 50 V s-l agrees with a quasi-reversible one-electron charge transfer complicated by sub-sequent chemical reactions (ipa/ipc increases from 0.86 at 0.02to 1 at 0.5 V s-'; AEp increases from 75 at 0.02 to 620 mV at 50 Vs-'; ipc/v* decreases by ca.20%). The same features hold as far asthe response B/C is concerned. At scan rates sufficient to preventthe chemical complications (it?., higher than 0.5 V s-'), it ispossible to evaluate the following formal electrode potentials:E"([Mo(CO)(q ,-C,Me,)L,] +-[Mo(CO)(q'-C,Me,)L,]) =- 0.77 V, .!?"([Mo(CO)(q5-C,Me,)L2]-[Mo(CO)(q5-C5Me5)-L2]-} = -1.41 V. In addition, assuming a first-order (orpseudo-first-order) reaction to be responsible for the instabilityof the species primarily generated at the electrode surface, it ispossible to compute15 a half-life of ca.50 s for both[Mo(CO)(q5-C5Me,)L2] and [Mo(CO)(q5-C,Me5)L2]-(L = PhCSPh). Although further investigations are neededto identify the final products resulting from these cathodicprocesses, it is interesting to underline that both one- andtwo-electron reduction processes of [Mo(CO)(q5-C,Me,)(PhC=CPh),] + do not cause immediate ligand losses.Diphenylacetylene molecules in [Mo(:CO)(q5-C,Me5)-(PhC=CPh)J+ act as three-electron ligands; l 6 it is likely thatthe two one-electron steps correspond to the sequentialconversion of t h e N o acetylenes into two-electron donors, sothat molybdenum does not exceed the effective atomic numberof 18; on the other hand the ability of acetylenes to act asvariable electron donors is well d ~ c u r n e n t e d .' ~ ~ ' ~ Thisbehaviour does not contradict the main features of theelectrochemical processes reported in the present paper; whilethe chemical reductions of [Mo(CO),(q5-C,Me,)L] + species,'Figure 5. Molecular structure of [Mo,(CO),(~~-C,M~,)~638 J. CHEM. SOC. DALTON TRANS. 1988Table 3. Fractional co-ordinates ( x lo4) with estimated standarddeviations in parenthesesXla1367.8(6)1 846(6)2 515(7)2 622(9)1687(7)2 269(7)3 582(8)3 791(8)2 543(13)447( 10)1733(10)4 697(9)5 168(9)1 646(9)1976(9)-1 899(5)-785(8)Y/b4 999.3(8)7 633(5)7 533(6)5 400(5)3 591(7)2 595(8)2 545(7)3 517(7)4 150(7)3 844(9)1 582(9)1 48 l(8)3 654(9)5 lOl(12)6 648(8)6 590(8)5 249(8)Z I C6 003.4(3)7 230(4)5 187(4)6 046(3)7 228(4)6 579(4)5 947(4)6 202(4)6 996(4)8 087(4)6 634(5)5 201(5)5 795(5)7 558(5)6 762(5)5 422(4)5 936(4)Table 4.Bond distances (A) and angles (O), with estimated standarddeviations in parenthesesMo-C( 1)Mo-C(2)MO-C(3)MO-C(4)MO-C(S)Mo-C( 1 1)Mo-C( 12)Mo-C( 13)Mo-cp0(1)-C(11)0(2)-C(12)Mo-Mo’C( 1 l)-Mo-C( 12)C( 1 1)-Mo-C( 13)C(lZ)-Mo-Mo’C( 13)-Mo-Mo’C( 1 l)-Mo-Mo’C( 12)-Mo-C( 13)C( 1 2 ) - M ~ pC( 1 ~)-Mo-cPMo‘-Mo-cPMo-C( 1 1)-O( 1)Mo-C( 12)-0(2)Mo-C( 13)-0(3)C( l)-c(2)-c(3)C(ll)-Mo-cp2.298(6)2.3 65 (7)2.406(7)2.376(8)2.304( 6)1.927(8)1.977(8)1.987(8)2.020( 7)3.278(4)1.163( 10)1.154(11)7733)77.7(4)74.8(2)67.9(2)121.4(2)11 3.3(3)113.7(3)123.0(4)123.7(3)124.8(2)178.6(8)170.6(6)168.5(6)108.1(6)1.148( 10)1.409(9)1.414(12)1.407(11)1.424(9)1.409( 10)1.521 (1 2)1.520( 12)1.506( 10)1.492( 13)1.506( 10)108.5(6)106.8(6)108.9(6)107.7( 6)125.9(7)125.8(7)125.0(6)126.3(6)125.0(7)125.9(7)126.7(6)1 2 5.7( 7)124.9(7)Prime indicates position, -x, 1 - y , 1 - z.cp is the centre of thecyclopentadienyl ring.being ligand centred, do not alter either the oxidation stateor the effective atomic number of molybdenum, the electro-chemical reductions are metal centred and when the effectiveatomic number, 18, is exceeded a fast dissociative step takes place.X-Ray Structure of [ M o ~ ( C O ) ~ ( ~ 5-C5Me,)2].-The crystalstructure of [Mo,(CO),(q ’-C,Me,)] is shown in Figure 5.Theco-ordinates of the non-hydrogen atoms are listed in Table 3,and bond distances and angles are collected in Table 4. Themolecular structure of [Mo,(CO),(~~-C,M~,)~] comparesvery well with that of analogous [M,(CO),(~5-C,H,)2]compounds (M = Cr, Mo, or W).” The two moieties of themolecule in the unit cell are related only by the inversion centre.However, the arrangement approximately displays two otherelements of symmetry: (i) a mirror plane passing through theTable 5. Experimental data for the crystallographic analysis *Compound CMo,(CO)& 5-C5Me5)21Space group p2,lcFormula cl JH 1M 3 15.2a/A 9.389(8)blA 9.1O4(4)C I A 17.1 12( 10)PI O 115.68(8)UjAJ 1318(2)Z 2DJg ~ m - ~ 1.588F(0W 636Temperature/K 295Crystal size/mmDiffractometer Ital Structuresp/mm-’ 0.964Scan speed/” s-lScan width/” 1.20 (in o)0.20 x 0.28 x 0.450.1 (in o)Radiation Mo-K,8 range/” 3-25h range &12k range 12- 121 range IS-18Standard reflection 31 1Intensity variation NoneNo.of measured reflections 3 680Condition for observed reflections F, > 30(F0)No. of reflections used in the refinement 1 346Scan mode 8/280.0220Max. shift to error ratioNo. of refined parameters 169R = ~IAWlFOl 0.037 1R’ = ICW(AF)~/CWF,~~~ 0.0328S = ICw(Af12/(N - P)liLi’ 1/[02(F,,) + O.OO0 095Fo2]* N = Number of observations, P = number of parameters.0.4Min. max.height in final Ap/e A-3 -0.7, 0.42.69molybdenum atoms and the centres of the cyclopentadienylrings, (ii) a perpendicular two-fold axis, with a resultingapproximate site symmetry 2/m (C,,). The co-ordinationpolyhedron around molybdenum could be described as adistorted square pyramid having the base on C(11), C(12),C(13), and the symmetry related Mo atom, and the vertex onthe centre of the cyclopentadienyl ring. The major cause ofdistortion in the pyramid is related to the large differencebetween Mo-CO and Mo-Mo’ distances.The Mo-Mo’ distance of 3.278 A, which is significantlylonger than that observed in [M02(CO)6(q5-C5H,),] (3.235is likely to be affected by the difference in hindrancebetween C5H5 and C5Me5.The cyclopentadienyl rings areplanar as could be expected, and the methyl groups lie just outof the plane (0.174.20 A) on the opposite side relative tomolybdenum.The average Mo-CO distance of 1.964 8, is not significantlyshorter than the 1.977 A observed in [M02(CO)6(T15-C5H5)],but in our case there is a larger dispersion in the distances. Inboth cases however, the shortest Mo-CO distance correspondsto the carbonyl group lying on the approximate symmetry planeand the related Mo-C-0 bond angle is the nearest to 180”.ExperimentalAll preparations were carried out under an atmosphere ofpurified nitrogen; solvents were dried and purified by reflux overa suitable drying agent and distilled under nitrogenJ.CHEM. SOC. DALTON TRANS. 1988 639Synthesis of the Complexes.-The complexes [Mo(CO),(q5-C,Me,)L]BF, [L = CO, p-MeC,H,NC, or P(OMe),] wereprepared as previously reported.[Mo(CO)(q5-C,Me5)(PhC=CPh),]BF4. [M0(c0),(q5-C,Me,)]BF, (1.264 g, 3.14 mmol) dissolved in CH2C12 (10cm3) was added dropwise at - 30 "C to a solution contain-ing P h C g P h (1.339 g, 7.51 mmol) in CH,Cl, (5 cm3). Thetemperature of the red solution obtained was raised to roomtemperature and diethyl ether (50 cm3) was added. A yellowmicrocrystalline solid started to precipitate; by cooling at-78 "C for 2 h, the amount of yellow solid increased. Thesolid was filtered off, washed with diethyl ether, and vacuumdried; yield 1.609 g (2.29 mmol, 72.8%) (Found: C, 66.5; H, 4.6.Calc.for C,,H3,BF,MoO: C, 66.7; H, 5.0%). 1.r. (Nujol)v(C-0) 2040vs cm-'. 'H N.m.r. (CDCl,, SiMe,): 6 2.0 (s,15 H, C,Me,), and 7.2-7.9 (m, 20 H, C,H,).[Mo,(CO),(q5-C,Me,),{P(OMe),},]. To a solution con-taining [M02(CO),(q5-C5Me,),] in toluene (20 cm3) an excessof P(OMe), (0.4 g) was added. The resulting suspension wasrefluxed for 24 h. An orange-yellow solution formed, fromwhich [ M 02( CO),( q ,-C,Me,), { P(OMe), } ,] was obtained asa yellow solid in 20% yield after column chromatography(CHCl, eluant; silica gel column). 1.r. (Nujol) v(C-0) 1940s,1 860s cm-'. 'H N.m.r. (CDCl,, SiMe,): 6 1.96 (s br, 30 H,C,Me,), 3.67 [d, 9 H, P(OMe),], and 3.77 [d, 9 H, P(OMe),].X-Ray Data Collection.-The relevant details of crystalparameters, data collection, and structure refinement for[ M o ~ ( C O ) , ( ~ ~ - C ~ M ~ ~ ) ~ ] are summarized in Table 5.Theunit-cell dimensions were determined by least-squares fitting ofthe 8 angles of 24 intense reflections chosen from diverse regionsof reciprocal space in the 11-15" 8 range. The reflectionintensities were corrected for Lorentz and polarization effects.The structure was solved by Patterson and Fourier techniquesand refined by the full-matrix least-squares method using theSHELX 76 program.20 Twelve of the fifteen hydrogen atomswere located from a difference Fourier synthesis. The remainderwere introduced in calculated positions; the positionalparameters of hydrogens were not refined. Atomic scatteringfactors and anomalous scattering coefficients were taken fromthe literature." Calculations were carried out on the IBM3081/K computer of the Centro Nazionale Universitario diCalcolo Elettronico, C.N.R., Pisa.PARST 2 2 and ORTEP 23programs were used for the geometrical calculations andstructure drawing.Electrochemistry.-Both the materials and the apparatusused in the electrochemical tests have been describedel~ewhere.~, Potential values refer to a saturated aqueouscalomel electrode (s.c.e.). Under the present experimental con-ditions, in dichloromethane solution the [Fe(q5-C5H5),]+-[Fe(q5-C,H5),] couple is located at +0.49 V. Thetemperature was controlled at 20 f 0.1 "C.AcknowledgementsWe gratefully thank Dr. M. Pasero for help in collection ofthe intensity data, and the Ministry of Education for financialsupport.References1 P.Leoni, E. Aquilini, M. Pasquali, F. Marchetti, and M. Sabat, J.2 W. E. Geiger, P. H. Rieger, B. Tulyathan, and M. D. Rausch, J. Am.3 K. M. Kadish, D. A. Lacombe, and J. E. Anderson, Inorg. Chem.,4 D. S. Ginley and M. S. Wrighton, J. Am. Chem. SOC., 1975,97, 3533.5 P. Leoni, E. Grilli, M. Pasquali, and M. Tomassini, J. Chem. SOC.,6 T. J. Meyer and J. V. Caspar, Chem. Rev., 1985,854434.7 C. E. Philbin, A. S. Goldman, and D. R. Tyler, Inorg. Chem., 1986,25,8 A. E. Stiegman and D. R. Tyler, J. Am. Chem. SOC., 1985, 107,967.9 R. J. Haines, R. S. Nyholm, and M. H. B. Stiddard, J . Chem. SOC. A,10 R. B. King, K. H. Pannel, C. A. Eggers, and L. W. Houk, Znorg.11 R. J. Haines and C. R. Nolte, J. Organornet. Chem., 1970, 24, 725.12 P. Hackett, P. S. ONeill, and A. R. Manning, J. Chem. SOC., Dalton13 D. J. Darensbourg, Adv. Organomet. Chem., 1982, 21, 113.14 D. J. Kuchynka, C. Amatore, and J. K. Kochi, Znorg. Chem., 1986,25,15 R. S. Nicholson and I. Shain, Anal. Chem., 1964, 36, 706.16 K. A. Mead, H. Morgan, and P. Woodward, J. Chem. SOC., Dalton17 B. Capelle, A. L. Beauchamp, M. Dartiguenave, and Y.18 J. L. Davidson and G. Vasapollo, J. Chem. SOC., Dalton Trans., 1985,19 R. D. Adams, D. M. Collins, and F. A. Cotton, Inorg. Chem., 1974,13,20 G. M. Sheldrick, SHELX 76, Program for Crystal Structure21 'International Tables for X-Ray Crystallography,' Kynoch Press,22 M. Nardelli, Comput. Chem., 1983, 7, 95.23 C. K. Johnson, ORTEP, Report ORNL 3794, Oak Ridge National24 F. Cecconi, C. A. Ghilardi, S. Midollini, A. Orlandini, and P. Zanello,Chem. SOC., Dalton Trans., 1988, 329.Chem. SOC., 1984, 106, 7000.1986, 25, 2246.Dalton Trans., 1986, 1041.4434.1968, 43.Chem., 1968, 7, 2353.Trans., 1974, 1625.4087.Trans., 1983, 271.Dartiguenave, J. Chem. SOC., Chem. Commun., 1982, 366.2239.1086.Determinations, University of Cambridge, 1976.Birmingham, 1974, vol. 4.Laboratory, Tennessee, 1965.Polyhedron, 1986, 5, 2021.Received 2nd March 1987; Paper 7138

ISSN:1477-9226    

DOI:10.1039/DT9880000635

出版商:RSC    

年代:1988

数据来源: RSC