Organometallics 1995, 14, 3497-3506
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Reactions of Monocyclopentadienyl PentafluorobenzenethiolatoComplexes of Molybdenum and Tungsten with Group 11 Metal Derivatives: Crystal and Molecular Structures of [Au(PPhdd[Mo(SCd%)4(qs-C~H~)l and [Cu(PPh3)31 [Mo(SCSF5)4(q6-CsHs)1 Jack L. Davidson,* W. Edward Lindsell," Kevin J. McCullough,* and Calum H. McIntosh Department of Chemistry, Heriot-Watt University, Riccarton, Edinburgh EH14 445, U.K. Received January 18, 1995@ Displacement of coordinated Tl(1) as TlCl from [TlM(SCsF5)4Cp] (M = Mo, W; Cp = q5C5H5) by gold complexes [AuCl(PR3)1 (R = Ph, Et) in dichloromethane or acetone solution isolable in higher yields from reactions affords ionic products [Au(PR~)~][M(SC~F~)~CP], carried out in the presence of three molar equiv of free phosphine, PR3. Ligand exchange between [Au(PPh3)3l[M(SCsF5)4Cpland diphosphines produces derivatives [Au(PhzP(CHz),PPh2)2][M(SCsF5)4Cp] { n = 2 dppe (4); n = 3 dppp (5); M = Mo, W). A related reaction of [CuCl(PPh3)31and [TlMo(SC6F5)4Cpl forms the copper derivative [Cu(PPh3)3l[Mo(SCsF5)4Cp] as the major product. Attempts to isolate derivatives with group 11 metal cations coordinated by anions [M(SC6F5)4Cp]- have been unsuccessful. Molecular structures of crystalline bimetallic species [M'(PR~)~][MO(SC~F~)~C~I.~.~CHZC~Z { M = Au (2a), Cu (6)) have been determined by X-ray diffraction and are essentially isomorphous. Both contain approximately trigonal-planar [M'(PPh&]+ cations with P-Au-P angles of 123.83(5)", 122.28(5)", and 113.62(5)" and a n average Au-P distance 2.386(2) 8, or P-Cu-P angles 121.24(7)", 123.44(8)" and 115.11(7)" and a n average Cu-P bond length 2.295(2) 8,, respectively. The discrete anions [Mo(SCsF5)4Cpl- in 2a and 6 are similar, with "four-legged piano-stool" geometry and average Mo-S distances of 2.421(2) or 2.420(3) A, respectively. Spectroscopic studies of complexes 4 and 5 support ionic constitutions with four-coordinated [Au((PhzP(CHz),PPhz)z]+ cations. Variable temperature 19F NMR studies of anions [M(SCsF5)4Cp]- of gold derivatives give barriers to fluxional rotatiodinversion of SCsF5 groups, AG* ca. 40-41 kJ mol-' (208-228 K), M = Mo, or AG* ca. 43-44 kJ mol-l(223-245 K), M = W, comparable with AG* values for salts [N(PPh3)zl[M(SCsF5)4Cpl,which are essentially independent of solvent (CDzC12, (CD&CO, or C&CD3), in contrast to barriers for coordinated species [TlM(SCsF5)4CpI. Previously we have described the synthesis of molybdenum and tungsten tetrathiolate anions [M(SC85)4Cpl(Cp = ~,7~-C5H5) which reversibly coordinate thallium(1) in and more recently we have observed reversible coordination of alkali metal ions.3 These results are interesting in view of the differing soft and hard acid characteristics, respectively, of the two types of metal cations. A feature of the complex anions which promotes coordination to metal ions is the presence of a cavity defined by the transition metal, the four sulfurs, and four of the eight ortho fluorines of the thiolate C,F5 substituents. An X-ray e a c t i o n study of [TlM(SC85)4Cpl (la,M = Mo) suggests that the primary bonding between the anion and T1+ involves the four sulfurs, i.e., a soft acidhase system, whilst the four fluorineAbstract published in Advance ACS Abstracts, June 1, 1995. (1)Bakar, W. A. W. A,; Davidson, J. L.; Lindsell, W. E.; McCullough, K. J.; Muir, K.W. J. Chem. SOC.,Dalton Trans. 1989, 991. (2)Bakar, W. A. W. A,; Davidson, J. L.; Lindsell, W. E.; McCullough, K. J. J. Chem. SOC.,Dalton Trans. 1990, 61. (3) Davidson, J. L.; McIntosh, C. H.; Leverd, P. C.; Lindsell, W. E.; Simpson, N. J. J. Chem. SOC.,Dalton Trans. 1994, 2423.Boyd, A. S. F.; Davidson, J. L.; McIntosh, C. H.; Leverd, P. C.; Lindsell, W. E.; Simpson, N. J . J. Chem. SOC.,Dalton Trans. 1992, 2531. @
thallium interactions are probably minimal.l The nature of the alkali metal-anion bonding has not yet been definitively established by a crystal structure but it is likely that fluorine-cation interactions are more important here.3q4 It is of interest to extend the chemistry of the anions [M(SCsF5)4Cpl- (M = Mo, W)by studying (4) Cf.: Plenio, H.; Burth, D. J. Chem. Soc., Chem. Commun. 1994, 2297.
Q276-7333/95/2314-3497$09.QQIQ 0 1995 American Chemical Society
3498 Organometallics, Vol. 14, No. 7, 1995
their interactions with a wider range of metal derivatives and to investigate the limits of their coordination capabilities. We now report the results of some of these studies with systems containing the sof't acid metal ions of group 11.
Results and Discussion Synthetic studies. Reactions of ['J!lM(SCsFs)&pI (M = Mo, W)with [ A u c l ( P R ~ ) (R l = Ph, Et). The complex [AuCl(PPh3)1,as a soluble source of Au(I), was reacted with a n equimolar quantity of [T1Mo(SCsF5)4Cp] (la)in tetrahydrofuran. From this reaction the only new, isolable product was obtained as orange-red crystals, incorporating PPh3 and Cp in the stoichiometric ratio 3:1, as shown by the lH NMR spectrum. Reaction with an additional 3 equiv (i.e., a n excess) of free triphenylphosphine gave the same orange-red crystals but in a considerably increased yield (>40%). It had been anticipated that the cationic gold center might coordinate to the soft sulfur sites of the tetrathiolate anion after elimination and precipitation of TlC1, possibly accompanied by the loss of PPh3. However, elemental and NMR spectroscopic analyses were consistent with the ionic formulation [Au(PPh&l[Mo(SC&5)4Cpl(2a) solvated in the crystals with 0.5 mol of CH2C12,
as confirmed by X-ray analysis (see below). The analogous tungsten reaction with [T1W(SCsF5)4Cpl(lb)gave yellow crystals which showed similar NMR spectra to those of 2a; elemental analyses of these crystals also corresponded to a related, but unsolvated, compound, [AU(PP~~)~I[W(SC~F~)*C~~(~~), obtained in 62% yield. Reaction of [TlMo(SCsF5)4CpIwith [AuCl(PEt3)3and three equivalents of PEt3 in CH2Clz yielded orangered crystals for which the lH NMR spectrum showed that PEt3 and Cp were present in a molar ratio of 3:l. The complex is formulated as an ionic species [Au(PEt3)3I[Mo(SCsF5)4Cpl(3a), similar to 2a, and this is supported by elemental analysis and dynamic I9FNMR studies (see below). The related reaction of [TlW(SCsFd4CpI with [AuCl(PEt3)1 and 3 equiv of PEt3 in acetone yielded two new crystalline species. The major product was obtained in the form of yellow crystals, with the minor product as light green crystals, and these were separated by hand. Both types of crystal gave identical IR, WMS, and NMR spectra in solution and the spectroscopic and analytical data of both forms indicated the same stoichiometric formula [Au-
Davidson et al.
( P E ~ ~ ) ~ ] [ W ( S C ~ F(3b), ~ ) ~analogous CPI to the molybdenum derivative 3a. Reactions of [Au(PPh&l [M(SCsF5)4(Cp)l (M = Mo, W) with diphosphines. Initially [Au(PPh&l[Mo(SCsF~kCpl(2a) was reacted with 1molar equiv of the potentially bidentate ligand 1,2-bis(diphenylphosphino)ethane (dppe) in CH2C12. The product that separated first from solution formed orange needlelike crystals (4a) which contained dppe and Cp ligands in a 2:l molar ratio, as shown by the 'H NMR spectrum, and only one type of C6F5 group was evident from the 19F NMR spectrum; further crystallization from the mother liquor only produced unreacted starting complex 2a. The reaction was therefore repeated with 2 molar equiv of dppe to form 4a in almost double the yield (95%). Reaction between tungsten complex 2 b and 2 equiv of dppe gave green, needlelike crystals which showed similar spectroscopic data to those of the molybdenum analogue. On the basis of analytical and spectroscopic analyses the complexes were formulated as [Au(dppe)zI[M(SC6F5)4Cp] {M = Mo (4a), W (4b)). Similarly, (2a or 2b) with reactions of [Au(PP~~)~I[M(SC~F~)~CPI 2 molar equiv of 1,3-bis(diphenylphosphino)propane (dppp) in acetone gave new products as orange (M = Mo) or yellow (M = W) microcrystals for which NMR spectra and analytical data indicated a formula [Au(dppp)23[M(SC6F5)4(Cp)l{M = Mo Gal, W (5b)). Reaction of [TlMo(SCsFs)rCpl with [CuCl(PPhdsl. Reaction of [TlMo(SCsF~)4CpIwith 1 molar equiv of [CuCl(PPh3)31 in CHzClz produced a mixture of two isolable crystalline species. The major product was obtained as red crystals (25%), which were contaminated with a small amount of dark crystals. The products were separated by hand, with the red crystals being suitable for structural analysis by X-ray diffraction (see below). The lH and 19FNMR spectra of these red crystals in CD2Cl2 at ambient temperature included several resonances assignable to Cp and C6F5 groups, suggesting that more than one species exists in solution a t this temperature; however, elemental analyses of the isolated crystalline product were consistent with the (6),and formula [Cu(PPh3)~l[Mo(SC~F~)~Cpl'O.5CH2C12 this was supported by low-temperature NMR spectra. The yield of dark crystals was too low for satisfactory characterization. Other Reactions Involving G r o u p 11Metal Derivatives. Attempts were made to form simple complexes containing the group 11 ions, such as [MM(SC6F5)4Cp] ( M = Au, Ag, CUI, in the absence of phosphorus ligands. Thallium derivatives [ m ( s C ~ F 5 ) 4 Cpl {M = Mo ( l a ) , W (lb)}can be prepared by ligand exchange reactions in polar organic solvents between TlSCsF5 and M(IV) cyclopentadienyl halides, such as [MC13(C0)2Cpl,or between TlSCd'5 and Mo(I1) species, e.g., [MoCl(C0)3CpI,followed by ~xidation.l-~However, related reactions of AuSC~F$ with M(IV) or Mo(I1) derivatives in tetrahydrofuran, under various conditions, did not produce stable, isolable products; in several reactions impure, blue-green paramagnetic species were formed, and much AuSC6F5 was recovered, mixed with metallic gold. Related reactions with various Ag(1) and Cu(1) salts also gave uncharacterizable products. Since AuSCsF5 is extremely insoluble, reac(5) Peach, M. E. Can. J. Chem. 1968, 46, 2699. Beck, W.; Stetter, K. H.; Tadros, S.; Schwarzhans, K. E. Chem. Ber. 1967, 100, 3944.
[Au(PPh3)a7[Mo(SCsFs)4(r15-CgH5)1 and [ C U ( P P ~ ~ ) ~ I ~ M O C S C ~ ~ ; )Organometallics, ~ ( ~ ~ ~ - C ~ HVol. ~ ) I14, No. 7, 1995 3499 Table 1. Fractional Coordinates of Atoms and U,, Values Comdex 2a atom X Y z U, atom 0.078 27(4) 0.132 35(13) -0.017 9(3) 0.030 6(3) -0.102 6(3) -0.136 3(3) -0.159 l(3) -0.238 3(3) -0.116 4(3) -0.170 4(3) -0.038 6(3) -0.003 9(3) 0.018 O(5) 0.250 59(14) 0.363 O(3) 0.286 O(3) 0.444 5(3) 0.446 1(3) 0.521 3(3) 0.605 O(3) 0.523 5(3) 0.598 5(3) 0.435 9(3) 0.437 4(3) 0.352 5(5) 0.003 97(14) 0.192 8(3) 0.201 4(3) 0.272 O(4) 0.352 4(4) 0.268 3(4) 0.344 3(4) 0.183 4(4) 0.175 6(4) 0.104 O(4) 0.023 7(4) 0.110 2(5) -0.112 26(14) -0.265 6(3) -0.218 6(3) -0.340 3(4) -0.382 6(4) -0.392 3(3) -0.472 l(3) -0.353 O(4) -0.397 2(4) -0.268 O(3) -0.233 7(3) -0.217 3(5) 0.174 4(4) 0.054 2(4) -0.002 2(4) 0.083 3(4) 0.192 4(4) 0.096 60(2) -0.042 35(12) -0.121 6(3)
0.563 71(3) 0.547 64(10) 0.436 80(19) 0.380 38(19) 0.414 68(23) 0.337 47(23) 0.471 O(3) 0.448 6(3) 0.548 66(25) 0.604 52(25) 0.571 40(20) 0.648 61(20) 0.516 4(4) 0.652 23(10) 0.667 63(20) 0.722 42(20) 0.651 72(24) 0.690 50(24) 0.594 23(25) 0.581 11(25) 0.558 87(24) 0.501 90(24) 0.570 53(23) 0.532 47(23) 0.627 8(3) 0.669 43(10) 0.720 19(25) 0.644 25(25) 0.775 O(3) 0.754 O(3) 0.852 7(3) 0.908 2(3) 0.873 5(3) 0.949 7(3) 0.818 35(21) 0.840 22(21) 0.737 6(4) 0.562 52(10) 0.614 21(25) 0.563 44(25) 0.668 7(3) 0.658 2(3) 0.719 70(25) 0.768 38(25) 0.726 7(3) 0.7804(3) 0.680 17(21) 0.687 37(21) 0.622 2(4) 0.449 4(3) 0.430 2(3) 0.462 1(3) 0.501 O(3) 0.493 l(3) 0.141 59(1) 0.159 07(9) 0.002 26122)
0.211 37(3) 0.328 21(8) 0.380 28(18) 0.342 04(18) 0.419 65(19) 0.419 ll(19) 0.455 78(19) 0.497 27(19) 0.460 34(19) 0.496 14(19) 0.416 96(17) 0.419 62(17) 0.375 9(3) 0.224 54(8) 0.352 05(18) 0.367 04(18) 0.400 lO(19) 0.461 Ol(19) 0.387 85(21) 0.434 56(21) 0.324 34(21) 0.311 66(21) 0.277 52(18) 0.216 48(18) 0.287 6(3) 0.148 28(9) 0.076 79(19) 0.052 98(19) 0.061 50(21) 0.019 31(21) 0.086 50(25) 0.068 84(25) 0.127 36(25) 0.150 60(25) 0.141 97(20) 0.184 OO(20) 0.122 6(3) 0.253 90(8) 0.151 44(20) 0.107 35(20) 0.127 31(23) 0.063 29(23) 0.171 26(25) 0.148 36(25) 0.236 7(3) 0.279 5(3) 0.258 83(21) 0.324 25(21) 0.216 9(3) 0.191 78(23) 0.192 09(23) 0.135 51(23) 0.100 24(23) 0.135 02(23) 0.262 41(1) 0.173 34(7) 0.182 83(19)
0.0387(3) C(2) 0.0479(9) 0.048(4) 0.070(3) 0.056(4) 0.090(3) 0.066(5) 0.094(4) 0.053(4) 0.087(3) 0.050(4) 0.073(3) 0.045(4) 0.0495(10) 0.050(4) 0.075(3) 0.057(4) 0.093(3) 0.063(5) 0.096(4) 0.057(4) 0.091(4) 0.054(4) 0.082(3) 0.044(4) 0.0526(10) 0.061(5) 0.084(3) 0.070(5) 0.109(4) 0.082(6) 0.127(5) 0.076(6) 0.124(5) 0.062(5) 0.082(3) 0.054(4) 0.0508(10) 0.059(5) 0.082(3) 0.070(5) 0.119(5) 0.072(5) 0.115(4) 0.074(6) 0.117(4) 0.059(5) 0.084(3) 0.051(4) 0.066(5) 0.063(5) 0.063(5) 0.064(5) 0.067(5) 0.0329(1) 0.0356(8) 0.048(4)
(Az>with Estimated Standard Deviations for X
-0.202 7(3) -0.308 6(3) -0.333 5(3) -0.252 4(3) -0.146 4(3) 0.082 2(3) 0.133 7(3) 0.121 5(3) 0.057 8(3) 0.006 3(3) 0.018 5(3) -0.177 6(3) -0.254 O(3) -0.285 7(3) -0.241 O(3) -0.164 5(3) -0.132 8(3) 0.301 03(12) 0.286 4(3) 0.326 8(3) 0.440 9(3) 0.514 6(3) 0.474 l(3) 0.360 O(3) 0.417 O(4) 0.462 2(4) 0.470 9(4) 0.434 4(4) 0.389 2(4) 0.380 5(4) 0.302 4(3) 0.341 O(3) 0.427 O(3) 0.474 4(3) 0.435 7(3) 0.349 7(3) 0.0457 7(12) -0.045 3(3) -0.041 O(3) 0.052 l(3) 0.140 9(3) 0.136 6(3) 0.043 6(3) 0.198 9(3) 0.284 6(3) 0.320 3(3) 0.270 2(3) 0.184 4(3) 0.148 7(3) -0.190 9(3) -0.300 4(3) -0.312 3(3) -0.214 7(3) -0.105 3(3) -0.093 4(3) 0.501 2(3) 0.414 4(18)
Y
z
u,
-0.061 70(22) 0.173 42(19) 0.066(5) -0.052 89(22) 0.138 24(19) 0.077(6) 0.019 90(22) 0.112 45(19) 0.078(6) 0.083 88(22) 0.121 86(19) 0.065(5) 0.075 05(22) 0.157 06(19) 0.041(3) 0.244 27(19) 0.087 58(17) 0.051(4) 0.257 Ol(19) 0.028 03(17) 0.062(5) 0.198 82(19) -0.025 52(17) 0.063(5) 0.127 85(19) -0.019 52(17) 0.061(5) 0.115 12(19) 0.040 02(17) 0.049(4) 0.173 31(19) 0.093 58(17) 0.038(3) 0.282 24(23) 0.129 23(15) 0.050(4) 0.343 50(23) 0.138 44(15) 0.062(5) 0.366 78(23) 0.202 69(15) 0.071(5) 0.328 77(23) 0.257 74(15) 0.067(5) 0.267 51(23) 0.248 53(15) 0.054(4) 0.244 25(23) 0.184 27(15) 0.039(3) 0.162 80(9) 0.255 43(7) 0.0362(8) 0.311 12(23) 0.321 75(20) 0.051(4) 0.377 Ol(23) 0.364 35(20) 0.067(5) 0.381 51(23) 0.391 53(20) 0.066(5) 0.320 13(23) 0.376 13(20) 0.060(4) 0.254 25(23) 0.333 52(20) 0.051(4) 0.249 74(23) 0.306 34(20) 0.039(3) 0.018 82(25) 0.242 14(15) 0.064(5) -0.049 81(25) 0.266 83(15) 0.087(6) -0.058 ll(25) 0.335 74(15) 0.075(5) 0.002 23(25) 0.379 96(15) 0.059(4) 0.355 27(15) 0.046(4) 0.070 86(25) 0.079 15(25) 0.286 36(15) 0.041(3) 0.117 OO(21) 0.121 05(19) 0.048(4) 0.118 02(21) 0.056 61(19) 0.057(4) 0.173 84(21) 0.043 20(19) 0.075(5) 0.094 23(19) O.b97(7) 0.228 63(21) 0.227 60(21) 0.158 66(19) 0.069(5) 0.171 79(21) 0.172 06(19) 0.042(4) 0.087 94(8) 0.364 43(7) 0.0332(8) -0.068 44(22) 0.376 08(20) 0.051(4) -0.151 41(22) 0.368 51(20) 0.064(5) -0.186 56(22) 0.339 05(20) 0.060(4) -0.138 75(22) 0.317 14(20) 0.060(4) 0.324 70(20) 0.050(4) -0.055 77(22) 0.354 16(20) 0.038(3) -0.020 62(22) 0.474 49(18) 0.041(3) 0.059 37(15) 0.524 77(18) 0.051(4) 0.083 32(15) 0.163 69(15) 0.535 79(18) 0.057(4) 0.496 55(18) 0.057(4) 0.220 09(15) 0.196 13(15) 0.446 27(18) 0.046(4) 0.435 24(18) 0.033(3) 0.115 77(15) 0.094 91(23) 0.350 62(15) 0.049(4) 0.371 31(15) 0.061(5) 0.111 94(23) 0.435 95(15) 0.067(5) 0.145 96(23) 0.162 97(23) 0.479 91(15) 0.063(5) 0.145 94(23) 0.459 22(15) 0.046(4) 0.394 57(15) 0.0383) 0.111 93(23) 0.065 31(21) 0.1663( 14) 0.469 73(24) 0.007 8(10) 0.108(6) 0.530 4(12)
tions were also investigated between l b or [N(PPh3)214. The two crystal structures are isomorphous, and the [Mo(SC6F5)4Cp] (7aI2 and the soluble complex [AuCllattices contain discrete ions [M(PPh3)31+ and [Mo(SMez)], from which the thioether can be displaced: (SC6F5)4Cp]- along with noninteracting, disordered despite visual and spectroscopic evidence for reactions molecules of CHzClz as solvent of crystallization (one molecule per unit cell). The packing arrangement of taking place, no pure products could be isolated from ions in 2a.0.5CHzC12 is depicted in Figure 1, and there these synthetic experiments. Solid State Structural Investigations. Structural are no si ificant non-bonding interionic contacts less analyses by X-ray diffraction were carried out on orangethan 3.5 The anion [Mo(SC$&Cpl-, as illustrated in Figure 2 for 2 a and in Figure 3 for 6, has a upianored crystals of [AU(PP~~)~~[M~(SC~F~)&~I.O.~CH~C~~, 2a.0.5CH2C12, and red crystals of [Cu(PPh3)3l[Mo(SCsF5)4stool" geometry closely related to that observed in CpI.O.5CH2C12,6.0.5CHzC12,both obtained from dichlo[ N ( P P ~ ~ ) ~ I [ M o ( S C ~(7aI2 F ~ ~ and C P I[TlMo(SC~F5kCpl romethane-hexane solutions at -15 to -20 "C. Frac(la1.1 The Mo-S bond lengths in complexes 2a and 6, tional atomic coordinates for 2 a and 6 are given in average 2.421 and 2.420 A, respectively, are essentially Tables 1 and 3,respectively, and selected geometrical the same as in 7a and la although there is a small parameters with standard deviations in Tables 2 and displacement of the S atoms toward the central axis in
3500 Organometallics, Vol. 14, No. 7, 1995
Davidson et al.
Table 2. Derived Geometrical Parameters for Complex 2a Bond Lengths (A) with Standard Deviations 2.4203(17) 2.3673(15) Mo(l)-S(l) Au(l)-P(l) 2.4336(17) 2.3990(15) Mo(l)-S(2) Au(l)-P(2) 2.4080(18) 2.3918(14) Mo(l)-S(3) Au(l)-P(3) 2.4201(17) 1.819(4) Mo(l)-S(4) P(l)-C(6) 2.281(5) 1.816(4) M0(l)-C(79) P(l)-C(12) 2.252(5) 1.817(4) Mo(l)-C(80) P(l)-C(18) Mo(l)-C(81) 2.326(5) P(2)-C(24) 1.805(4) 2.399(5) 1.834(4) Mo(l)-C(82) P(2)-C(30) 2.372(5) 1.813(4) Mo(l)-C(83) P(2)-C(36) S(l)-C(60) 1.770(6) P(3)-C(42) 1.821(4) 1.755(6) 1.816(4) S(2)-C(66) P(3)-C(48) 1.776(7) 1.810(4) S(3)-C(72) P(3)-C(54) 1.768(7) 1.866(21) S(4)-C(78) C1(1)-C(84) Angles (deg) with Standard Deviations P(l)-Au(l)-P(2) 123.83(5) Au(l)-P(3)-C(54) P(l)-Au(l)-P(3) 122.28(5) C(42)-P(3)-C(48) P(2)-Au(l)-P(3) 113.62(5) C(42)-P(3)-C(54) Au(l)-P(l)-C(G) 113.08(13) C(48)-P(3)-C(54) AU(l)-P(l)-C(lZ) 114.30(13) P(3)-C(42)-C(37) A~(l)-P(l)-C(l8) 116.26(13) P(3)-C(42)-C(41) C(6)-P(l)-C(12) 105.58(18) P(3)-C(48)-C(43) C(6)-P(l)-C(18) 103.42(18) P(3)-C(48)-C(47) C(12)-P( 1)-C(18) 102.89(18) P(3)-C(54)-C(49) P(l)-C(6)-C(l) 119.3(3) P(3)-C(54)-C(53) P(l)-C(6)-C(5) 120.6(3) S(l)-Mo(l)-S(2) P(l)-C(12)-C(7) 117.8(3) S(l)-Mo(l)-S(3) P(l)-C(l2)-C(ll) 122.2(3) S(l)-Mo(l)-S(4) P(l)-C(l8)-C(l3) 121.1(3) S(2)-Mo(l)-S(3) P(l)-C(l8)-C(l7) 118.7(3) S(2)-Mo(l)-S(4) A~(l)-P(2)-C(24) 113.00(13) S(3)-Mo(l)-S(4) Au(l)-P(2)-C(30) 111.28(14) Mo(l)-S(l)-C(GO) A~(l)-P(2)-C(36) 116.13(13) S(l)-C(60)-C(55) C(24)-P(2)-C(30) 105.04(19) S(l)-C(60)-C(59) C(24)-P(2)-C(36) 106.52(18) Mo(l)-S(2)-C(66) C(3O)-P(2)-C(36) 103.92(18) S(2)-C(66)-C(61) P(2)-C(24)-C(19) 118.3(3) S(2)-C(66)-C(65) P(2)-C(24)-C(23) 121.6(3) Mo(l)-S(3)-C(72) P(2)-C(3O)-C(25) 121.0(3) S(3)-C(72)-C(67) P(2)-C(3O)-C(29) 118.3(3) S(3)-C(72)-C(71) P(2)-C(36)-C(31) 117.3(3) Mo(l)-S(4)-C(78) P(2)-C(36)-C(35) 122.6(3) S(4)-C(78)-C(73) Au(l)-P(3)-d42) 109.43(13) S(4)-C(78)-C(77) A~(l)-P(3)-C(48) 113.68(12)
117.43(13) 105.42(17) 105.28(17) 104.64(17) 122.4(3) 117.6(3) 122.3(3) 117.46(25) 117.6(3) 122.4(3) 81.30(6) 135.72(6) 81.02(6) 82.33(6) 136.30(6) 83.12(6) 115.08(21) 124.2(4) 121.2(4) 113.98(21) 122.9(4) 123.4(4) 115.21(23) 126.1(5) 118.8(4) 118.24(22) 127.4(5) 118.0(4)
the latter species (mean trans angles S-Mo-S: 136.0' in 2a, 136.1' in 6, 132.0' in la) which is consistent with T1+ coordination to the sulfur atoms in la. A structurally related anion has previously been characterized in the bis(l,2-dithiolene) complex, [PPhd[Mo{S2C2(CN)2)2Cpl7with a mean Mo-S bond length of 2.407 A and a mean trans S-Mo-S angle of 135.5', indicative of a species in which the unsaturated chelating sulfur ligands act as dinegative dithiolate ligands. The three triphenylphosphine ligands of 2a are trigonally disposed about the Au atom in the cation [Au(PPh&]+, and the Au atom is displaced from the P3 plane by 0.072 A, see Figure 2. There is a degree of asymmetry, as indicated by P-Au-P angles of 123.83(5Y, 122.28(5Y, and 113.62(5)", giving an average P-Au-P angle of 119.9'. These angles and the average Au-P bond length of 2.386 A are comparable with those reported for the trigonal cation in the structurally characterized ionic thiaborane species [Au(PPh3)31[BgHlzSI: P-Au-P angles 124.1(2),121.5(2),and 112.3(2)O {average 119.3O); mean Au-P bond length 2.382(5) A.7 The cation [Cu(PPhs)al+of 6 contains Cu(1) in (6) (a) Locke, J.; McCleverty, J. A. Inorg. Chem. 1966,5, 1157. (b) Churchill, M. R.; Cooke, J. J. Chem. SOC.A 1970, 2046. (We thank a reviewer for drawing our attention to this work.)
an essentially trigonal planar coordination geometry with Cu located 0.061 A out of the P3 plane, see Figure 3. As in the cation [Au(PPh3)31+of 2a, there is some asymmetry in the disposition of triphenylphosphine ligands around Cu with P-Cu-P angles of 121.24(7)', 123.44(8)', and 115.11(7)' (mean 119.9') and an average Cu-P bond length of 2.295 A. Examples of simple tri-coordinated Cu(1) complexes are relatively rare. Phosphine halide complexes [CuX(PPh3)31have distorted tetrahedral coordination geometries? and even in compounds [Cu(PPh3)31[BF4I9 and [C~(PPh3)31[C1041'~ the formal cations [Cu(PPh3)3l+ interact, albeit weakly, with the poorly r'bonded anions, OC103- and FBF3-, respectively, to generate four-coordinate Cu(1) centers. These distorted four-coordinate complexes show average Cu-P distances in the range 2.30-2.35 A and P-Cu-P angles in the range 110-116'.10 However, distorted trigonalplanar geometry is observed in anionic trihalogenocuprates [C&I2-,l1 and, more significantly in the context of this work, [Cu(PPh3)3][V(CO)6]contains discrete trigonal cations [Cu(PPh3)31f and octahedral anions [v(co)61-.'2The geometrical parameters of the cation in [Cu(PPhs)sl[V(CO)6]are closely related to those in 6, which has a mean Cu-P distance of 2.295 A and mean P-Cu-P angle of 120.0°.12 Both yellow and light green crystals of [Au(PEt3)31[W(SC6F5)4Cp](3b)show indistiguishable properties in solution so that any structural difference is a solid state phenomenon. It is possible that an interaction between the Au(1) cation and the tetrathiolate anion in one of these forms, e.g., via the sulfur atoms, could account for the observed difference. The less bulky PEt3 groups of the Au(1) cation in complex 3b could conceivably permit such a cation-anion interaction which is precluded by the more sterically demanding PPh3 ligands of complex 2a. However, the IR spectra of both crystalline forms of 3b are virtually identical, e.g., strong CsF5 vibrations at 1506 and 1463 cm-l or at 1505 and 1461 cm-l for the yellow or green forms, respectively. Moreover, the UV/vis spectra for both solids in Nujol mulls are very similar, with one broad absorption band in the ca. 435 nm (yellow form) or ca. 440 visible region, ,A nm (green form). These data suggest that any differences in structure between the two solid state forms are relatively minor. Preliminary results from an X-ray structural investigation of a crystal of the green form indicates that it contains discrete [Au(PEt3)3]+cations and [W(SC6F5)4Cp]- anions with a structure analogous to that of complex 2a. The PEt3 groups were, however, too disordered to permit satisfactory refinement of this structure. NMR Spectroscopic Studies in Solution. NMR data for all new compounds are reported in the Experimental Section and are consistent with the ionic con(7) Guggenberger, L. J. J. Organomet. Chem. 1974,81, 271. (8) Barron, P. F.; Dyason, J. C.; Healy, P. C.; Engelhardt, L. M.; Pakawatchai, C.; Patrick, V. A.; White, A. H. J. Chem. SOC.,Dalton Trans. 1987, 1099. (9) Gaughan, A. P.; Dori, Z.; Ibers, J. A. Inorg. Chem. 1974, 13, 1657. (10)Dyason, J. C.; Engelhardt, L. M.; Healy, P. C.; Klich, H. L.; White, A. H. Aust. J . Chem. 1986, 39, 2003. (llIBowmaker, G. A,; Clark, G. R.; Rogers, D. A,; Camus, A.; Marsich, N. J. Chem. SOC.,Dalton Trans. 1984, 37. (12)Doyle, G.; Eriksen, K. A.; Engen, D. V. Organometallics 1985, 4 , 2201.
[Au(PPhd~~Mo(SC~~~(~-CsHsll and [Cu(PPhd~[Mo(SC~~~~-CgH5)1 Organometallics, Vol. 14, No. 7,1995 3501
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Table 3. Fractional Coordinates of Atoms and U,,Values (&) with Estimated Standard Deviations for Complex 6 atom X Y z U, atom X Y 2 u, 0.076 86(6) 0.002 53(18) 0.195 7(4) 0.198 8(4) 0.271 4(5) 0.354 2(5) 0.267 6(5) 0.347 5(5) 0.183 8(5) 0.175 3(5) 0.107 3(4) 0.023 6(4) 0.109 3(7) 0.250 03(18) 0.436 8(4) 0.436 2(4) 0.517 7(4) 0.597 9(4) 0.522 6(4) 0.601 1(4) 0.443 2(4) 0.447 3(4) 0.361 5(4) 0.286 7(4) 0.353 5(6) 0.131 20(17) -0.020 O(4) 0.031 l(4) -0.104 2(4) -0.136 l(4) -0.154 l(4) -0.240 9(4) -0.122 O(4) -0.169 2(4) -0.036 9(4) -0.006 O(4) 0.017 2(6) -0.114 06(17) -0.266 4(8) -0.232 5(5) -0.352 3(5) -0.397 O(5) -0.390 O(5) -0.473 8(5) -0.349 l(5) -0.381 3(5) -0.259 6(4) -0.227 2(4) -0.218 3(7) 0.083 O(7) 0.191 8(7) 0.172 l(7) 0.051 3(7) -0.003 8(7) 0.097 74(7) -0.037 95(16) 0.008 4(4)
0.561 6U4) 0.665 03(13) 0.713 2(3) 0.639 1(3) 0.769 O(3) 0.747 9(3) 0.847 2(3) 0.901 5(3) 0.867 l(3) 0.943 2(3) 0.811 72(25) 0.834 81(25) 0.731 9(5) 0.649 77(12) 0.571 5(3) 0.529 6(3) 0.555 4(3) 0.502 4(3) 0.597 4(3) 0.580 7(3) 0.652 4(3) 0.692 8(3) 0.666 6(3) 0.723 1(3) 0.626 3(5) 0.547 37(13) 0.439 35(25) 0.382 20(25) 0.416 9(3) 0.340 l(3) 0.472 8(3) 0.452 O(3) 0.551 5(3) 0.606 2(3) 0.572 8(3) 0.650 l(3) 0.517 8(5) 0.561 39(13) 0.677 4(6) 0.687 8 3 ) 0.727 O(3) 0.779 9(3) 0.719 8(3) 0.765 5(3) 0.661 8(3) 0.658 7(3) 0.616 9(3) 0.558 7(3) 0.620 2(5) 0.496 4(3) 0.489 3(3) 0.447 6(3) 0.429 O(3) 0.459 l(3) 0.137 83(5) 0.156 97(11) 0.114 74(25)
0.209 26(3) 0.144 34(11) 0.075 48(23) 0.047 08(23) 0.057 O(3) 0.016 2(3) 0.080 9(3) 0.065 8(3) 0.123 6(3) 0.146 l(3) 0.140 39(23) 0.179 82(23) 0.118 2(4) 0.222 02(10) 0.276 49(24) 0.216 74(24) 0.325 3(3) 0.312 5(3) 0.386 41(25) 0.435 30(25) 0.399 54(25) 0.460 12(25) 0.350 46(22) 0.364 07(22) 0.286 O(4) 0.327 07(10) 0.379 86(21) 0.344 04(21) 0.420 57(24) 0.422 59(24) 0.460 33(24) 0.497 66(24) 0.456 89(22) 0.497 31(22) 0.417 43(21) 0.417 55(21) 0.375 9(4) 0.251 74(11) 0.256 2(5) 0.322 3(3) 0.233 7(3) 0.276 9(3) 0.168 2(3) 0.145 4(3) 0.126 3(3) 0.060 3(3) 0.149 l(3) 0.106 O(3) 0.214 7(4) 0.098 OO(24) 0.134 lO(24) 0.191 92(24) 0.191 55(24) 0.133 51(24) 0.263 77(4) 0.178 18(9) 0.043 20(24)
0.0380(4) 0.0526(13) 0.057(6) 0.086(4) 0.073(7) 0.112(5) 0.081(8) 0.130(6) 0.076(7) 0.119(6) 0.054(6) 0.076(4) 0.046(5) 0.0499(13) 0.055(6) 0.086(4) 0.056(6) 0.093(4) 0.064(6) O.lOO(5) 0.059(6) O.lOO(5) 0.053(6) 0.079(4) 0.046(5) 0.0470(12) 0.049(5) 0.068(3) 0.057(6) 0.093(4) 0.064(6) 0.098(5) 0.058(6) 0.087(4) 0.053(6) 0.076(4) 0.042(5) 0.0513(13) 0.061(6) 0.088(4) 0.082(8) 0.125(6) 0.086(8) 0.115(5) 0.077(7) 0.121(6) 0.065(7) 0.091(5) 0.048(5) 0.064(6) 0.066(7) 0.062(6) 0.063(6) 0.062(6) 0.0338(5) 0.0357(11) 0.050(5)
stitutions proposed above. 'H NMR spectra show a singlet resonance for cyclopentadienyl H atoms and contain resonances assignable to H atoms of phosphine ligands and of solvated CH2Cl2, when present. 31P{1H} NMR spectra of species 2-5 comprise one singlet resonance shified to high frequency from the resonance of the free ligand and assignable to equivalent phosphine ligands coordinated to Au(1); observed coordination shifis are PPh3 43,PEt3 56-58, dppe 39, and dppp 14.5 ppm. At ambient temperature the 19FNMR spectra of all compounds in a range of solvents show simple spectra of four equivalent pentafluorophenyl groups in which ortho F atoms and, separately, meta F atoms are magnetically equivalent, as illustrated in Figure 4a for
0.057 9(4) 0.122 O(4) 0.136 5(4) 0.087 O(4) 0.022 9(4) -0.252 4(5) -0.334 O(5) -0.307 O(5) -0.198 3(5) -0.116 7(5) -0.143 7(5) -0.161 3(5) -0.238 8(5) -0.284 3(5) -0.252 4(5) -0.174 9(5) -0.129 4(5) 0.045 81(15) -0.192 5(4) -0.302 l(4) -0.313 2(4) -0.214 7(4) -0.105 2(4) -0.094 O(4) 0.183 3(4) 0.268 7(4) 0.318 5(4) 0.283 O(4) 0.197 7(4) 0.147 8(4) -0.045 3(4) -0.041 O(4) 0.051 7(4) 0.140 1(4) 0.135 8(4) 0.043 1(4) 0.294 22(16) 0.279 3(3) 0.319 4(3) 0.433 4(3) 0.507 4(3) 0.467 4(3) 0.353 4(3) 0.300 2(4) 0.340 7(4) 0.425 7(4) 0.470 2(4) 0.429 7(4) 0.344 7(4) 0.410 9(5) 0.456 2(5) 0.467 3(5) 0.433 O(5) 0.387 7(5) 0.376 6(5) 0.503 3(5) 0.577 8(23)
0.128 78(25) -0.016 97(24) 0.060(6) 0.199 43(25) -0.022 34(24) 0.066(6) 0.256 OO(25) 0.032 46(24) 0.062(6) 0.241 96(25) 0.092 64(24) 0.050(5) 0.171 33(25) 0.098 Ol(24) 0.039(4) 0.128 O(3) 0.066(6) 0.083 5(3) 0.020 O(3) 0.118 8(3) 0.085(8) 0.141 8(3) -0.053 4(3) 0.076(7) -0.063 3(3) 0.174 1(3) 0.062(6) 0.183 3(3) 0.000 2(3) 0.049(5) 0.160 3(3) 0.041(5) 0.073 6(3) 0.252 95(20) 0.056(6) 0.264 3(3) 0.262 05(20) 0.070(7) 0.324 6(3) 0.206 60(20) 0.070(7) 0.361 8(3) 0.142 04(20) 0.064(6) 0.338 7(3) 0.132 94(20) 0.043(5) 0.278 4(3) 0.188 39(20) 0.039(4) 0.241 2(3) 0.361 53(9) 0.0330(10) 0.086 77(11) 0.349 13(19) 0.046(5) 0.091 8(3) 0.370 19(19) 0.059(6) 0.108 4(3) 0.434 63(19) 0.063(6) 0.144 l(3) 0.478 02(19) 0.060(6) 0.163 2(3) 0.456 95(19) 0.047(5) 0.146 6(3) 0.392 50(19) 0.037(4) 0,110 9(3) 0.444 87(23) 0.044(5) 0.194 41(23) 0.495 93(23) 0.058(6) 0.218 34(23) 0.535 54(23) 0.058(6) 0.162 33(23) 0.524 11(23) 0.054(5) 0.082 39(23) 0.473 05(23) 0.041(5) 0.058 46(23) 0.433 43(23) 0.031(4) 0.114 48(23) 0.375 lO(25) 0.049(5) -0.068 7(3) 0.368 07(25) 0.065(6) -0.151 2(3) 0.338 08(25) 0.065(6) -0.186 3(3) 0.315 13(25) 0.060(6) -0.139 O(3) 0.322 17(25) 0.048(5) -0.056 5(3) 0.352 16(25) 0.035(4) -0.021 3(3) 0.255 57(9) 0.0365(11) 0.157 17(12) 0.319 7(3) 0.053(5) 0.306 l(3) 0.361 O(3) 0.067(7) 0.373 l(3) 0.067(7) 0.378 6(3) 0.389 2(3) 0.062(6) 0.317 l(3) 0.375 9(3) 0.049(5) 0.334 6(3) 0.250 1(3) 0.037(4) 0.306 5(3) 0.244 6(3) 0.120 53(25) 0.043(5) 0.111 9(3) 0.056 23(25) 0.058(6) 0.113 1(3) 0.043 42(25) 0.083(8) 0.169 8(3) 0.094 89(25) 0.092(8) 0.225 3(3) 0.159 20(25) 0.073(7) 0.224 l(3) 0.172 OO(25) 0.043(5) 0.167 3(3) 0.241 96(19) 0.064(6) 0.014 4(3) 0.266 71(19) 0.079(7) -0.053 8(3) 0.336 06(19) 0.073(7) -0.061 3(3) 0.380 67(19) 0.057(6) -0.000 7(3) 0.355 92(19) 0.045(5) 0.067 5(3) 0.286 57(19) 0.036(4) 0.075 O(3) 0.1895(20) 0.065 O(3) 0.468 3(3) 0.467 5(16) -0.010 l(13) 0.1200(0)
compound 3b. At low temperatures both the ortho and meta signals split into two equal-intensity resonances (e.g., see Figure 4) and the spectra correspond to stereochemically rigid C6F5 systems in which all five F atoms are inequivalent, as expected from the solid state structures. This fluxionality, previously observed in related deri~atives,l-~ involves concerted rotation of the C6F5 rings (or rotatiordinversion of C6F5S ligands) with pairwise interchange of ortho and meta F atoms. From the coalescence teaperatures of ortho and/or meta 19Fresonances values of AG* for this process can be calculated,13(Table 5). Values of AG* are temperature (13)Kost, D.; Carlson, E. H.; Raban, M. J. Chem. SOC.,Chem. Commun. 1971, 656.
Davidson et al.
3502 Organometallics, Vol. 14,No. 7, 1995 Table 4. Derived Geometrical Parameters for Complex 6 Bond Lengths (A) with 2.2890(20) Cu(l)-P(l) 2.2945(20) Cu(l)-P(2) Cu(l)-P(3) 2.3019(21) 1.817(5) P(l)-C(6) P(l)-C(12) 1.827(6) 1.816(5) P(l)-C(18) 1.821(5) P(2)-C(24) 1.815(5) P(2)-C(30) 1.823(5) P(2)-C(36) 1.814(5) P(3)-C(42) 1.819(5) P(3)-C(48) 1.837(5) P(3)-C(54) 1.78(3) Cl(l)-C(84)
Standard Deviations 2.4036(23) Mo(l)-S(l) Mo(l)-S(2) 2.4363(21) Mo(l)-S(3) 2.4210(22) 2.4182(22) Mo(l)-S(4) Mo(l)-C(79) 2.410(6) 2.375(6) Mo(l)-C(80) Mo(l)-C(81) 2.275(6) 2.249(6) Mo(l)-C(82) 2.335(6) Mo(l)-C(83) 1.771(8) S(l)-C(60) 1.768(8) S(2)-C(66) 1.769(8) S(3)-C(72) S(4)-C(78) 1.753(8)
Angles(deg) with Standard Deviations P(l)-Cu(l)-P(2) 121.24(7) Cu(l)-P(3)-C(54) 112.40(18) P(l)-Cu(l)-P(3) 123.44(8) C(42)-P(3)-C(48) 105.29(23) P(2)-Cu(l)-P(3) 115.11(7) C(42)-P(3)-C(54) 104.83(24) Cu(l)-P(l)-C(G) 113.89(17) C(48)-P(3)-C(54) 103.49123) C~(l)-P(l)-C(l2) 113.24(19) P(3)-C(42)-C(37) 117.9(4) C~(l)-P(l)-C(l8) 118.01(18) P(3)-C(42)-C(41) 122.1(4) C(6)-P(l)-C(12) 104.97(24) P(3)-C(48)-C(43) 117.0(4) C(6)-P(l)-C(18) 102.51(23) P(3)-C(48)-C(47) 122.8(4) C(l2)-P(l)-C(l8) 102.64(24) P(3)-C(54)-C(49) 120.8(4) P(l)-C(6)-C(l) 122.5(4) P(3)-C(54)-C(53) 118.4(4) P(l)-C(6)-C(5) 117.5(4) S(l)-Mo(l)-S(2) 82.49(7) P(l)-C(12)-C(7) 121.2(4) S(l)-Mo(l)-S(3) 135.99(8) P(l)-C(l2)-C(ll) 118.6(4) S(l)-Mo(l)-S(4) 83.06(8) P(l)-C(l8)-C(l3) 118.3(4) S(2)-Mo(l)-S(3) 81.24(7) P(l)-C(l8)-C(l7) 121.4(4) S(2)-Mo(l)-S(4) 136.18(8) C~(l)-P(2)-C(24) 118.50(17) S(3)-Mo(l)-S(4) 81.08(7) Cu(l)-P(2)-C(30) 113.44(16) Mo(l)-S(l)-C(GO) 114.9(3) CU(l)-P(2)-C(36) 110.06(17) S( 1)-C(60)-C(55) 126.2(5) C(24)-P(2)-C(30) 103.65(22) S(l)-C(60)-C(59) 118.6(5) C(24)-P(2)-C(36) 105.02(22) Mo(l)-S(2)-C(66) 114.2(3) C(3O)-P(2)-C(36) 105.01(22) S(2)-C(66)-C(61) 123.8(5) P(2)-C(24)-C(19) 117.4(3) S(2)-C(66)-C(65) 121.8(5) P(2)-C(24)-C(23) 122.6(3) Mo(l)-S(3)-C(72) 115.6(3) P(2)-C(3O)-C(25) 117.4(3) S(3)-C(72)-C(67) 123.7(5) P(2)-C(3O)-C(29) 122.4(3) S(3)-C(72)-C(71) 121.2(5) P(2)-C(36)-C(31) 122.7(4) Mo(l)-S(4)-C(78) 118.4(3) P(2)-C(36)-C(35) 117.3(4) S(4)-C(78)-C(73) 117.5(6) Cu(l)-P(3)-C(42) 112.14(18) S(4)-C(78)-C(77) 128.0(6) C~(l)-P(3)-C(48) 117.54(18)
dependent but only show small variations, virtually within experimental error, over the limited temperature ranges of coalescence points for comparable solventl substrate systems studied here. In CDzClz solution, ionic molybdenum or tungsten species 3 and 5, and the related salts [N(PPh3)21[M(SC&'5)4Cp] ( 7 ) , have AG* values for CsF5 motion, which vary only with the metal M (M = Mo, ca. 41 kJ mol-'; M = W ca. 43-44 kJ mol-'), and show no dependence on countercation. Derivatives (1) which coordinate Tl+ under these conditions1I2show significantly higher AG* values (M = Mo, 45.8 kJ mol-'; M = w,46.7kJ mol-'). Barriers t o C6F5 rotation of all the ionic derivatives are essentially independent of solvent, beingca. 40-41 or 43-44 kJ mol-' for Mo or W species, respectively, in CD2C12, (CD3)zCO or C&CD3 (see Table 5). In contrast, the thallium species (1) have significantly reduced barriers in acetone solution, with AGS values marginally below those of the simple ionic systems, and this is consistent with the previously noted dissociation of TI+ in this solvent; it,is possible that the dissociating Tl+ ion may also assist in the rotation of C6F5 groups. The singlet 31P{1H}NMR resonance, 6 21.6 ppm, for complexes 4 in CDzClz is virtually identical to that reported for the four-coordinate complex [Au(dppe)zl-
SbFs in solution (20.8ppm in CDC13).14 Also, complexes 5 give a singlet 31P(1H}NMR resonance (-2.0 ppm) which is unchanged for 5b on cooling to -80 "C, showing no evidence for uncoordinated phosphine functions a t this temperature when any exchange process between free and complexed phosphorus groups should be slow on the NMR time scale. Therefore, it may be concluded that compounds 4 and 5 contain four-coordinate cations [Au(diphosphine)z]+of bidentate dppe or dppp, respectively, with five- or six-membered chelate rings, and this is supported by the complex 'H resonances of the methylene H atoms of the phosphine ligands. Reports of chelated Au(1) complexes have mainly been confined to bidentate ligands with rigid backbones as in cations [Au{o-phenylenebis(dimethylarsine)}~l*,15 and flexible, bidentate ligands such as dppe tend to preserve linear coordination of Au(1) by formation of annular binuclear ~omp1exes.l~ However, bis-chelation of Au(1) by dppe has been established in crystalline [Au(dppe)slSbFgMe2C014and [A~(dppe)~]C1*2H20'~ which contain approximately tetrahedral or flattened tetrahedral cations. The 19F NMR spectrum of red compound (6) in CD2Cl2 at -80 "C is dominated ('88%) by five broadened resonances of equivalent, rigid C6F5 groups which are most probably assignable to the dissolved ionic derivative, [Cu(PPh3)31[Mo(SCsFs)4CpI,present in the solid state. At higher temperatures the resonances of meta and ortho F atoms pass through coalescence points, ca. -60 and -45 "C, respectively, to produce a spectrum of three broadened resonances from fluxional C6F5 groups at room temperature. However, even at low temperatures, small resonances due to other pentafluorophenyl species are present in these spectra and these bands increase in intensity a t higher temperatures. It appears that ionic [Cu(PPh&l[Mo(SCsF5)4Cplis somewhat unstable in solution and may be in equilibrium with decomposition products. It is likely that the three-coordinate cation [Cu(PPh3)31+could undergo ligand redistribution reactions causing consequent interactions with the anion [Mo(SC6F5)4Cpl-.
Conclusions Complexes [TlM(SC$5)4Cp] (M = Mo, W) react with Au(I) species in the presence of phosphine ligands, PR3 (R = Ph, Et), to form ionic derivatives [Au(PR&I[M(SCsF5)4Cpl as the only identifiable new products from reaction systems with molar ratios of reactants Au(I):PR3 varying from 1:l to 1:4. It therefore appears that the anions [M(SC6F5)&p]- do not compete effectively in the coordination to Au(1) in comparison with monodentate phosphine ligands or with bidentate phosphines (dppe, dppp) which readily form compounds [AU(P~~P(CH~),PP~~)~I[M(SC~F~)~CPI. It should be noted that phosphine ligands do interact with thallium derivatives (1)and decoordination of Tl(1)from the organometallic anions is observed under some conditions: dissociation of phosphine complexed T1+ ions (14)Berners-Price, S. J.; Mazid, M. A.; Sadler, P. J. J . Chem. Soc., Dalton Trans. 1984, 969 (15)Uson, R.; Laguna, A,; Vicente, J.; Garcia, J.; Jones, P. G.; Sheldrick, G. M. J . Chem. SOC.,Dalton Trans. 1981, 655. (16)Bates, P. A.; Waters, J. M. Inorg. Chim. Acta 1984, 81, 151
P
a
Figure 1. Packing diagram for complex 2a depicting the unit cell contents. The disordered CH2C12 molecule has been
omitted for clarity.
Figure 2. Molecular structure of complex 2a (ORTEP 30% probability elipsoids). Labels for the F and H atoms are taken from the carbon atom to which they are bonded.
is favored in polar solvents, such as acetone, and by more basic phosphine ligands, such as PEt3 and PMe2Ph.1,2 Attempts to characterize complexes of [M(SC6F5)4Cp]with Au(1) or other coinage metals in the absence of phosphine ligands were unsuccessful, and it is possible that, in contrast to their facile coordination to T1+, the complex anions are unexpectedly poor ligands towards these metals. Our failure to isolate complexes of the type [AuM(SC6F5)4Cp]may be a result of unfavorable geometry of the cavity and the four planar S-donor sites since Au(1) does form complexes with other sulfur ligands under similar reaction conditions to those employed here. The fact that anions [M(SCsF&Cp](M = Mo, W) more readily form isolable, ionic solids with lattices containing relatively uncommon trigonal tricoordinate complexes [Au(PR&]+ or [Cu(PPh&]+ as
countercations could be the result of favorable crystal packing of these ions.
Experimental Section All reactions and operations were conducted under an atmosphere of dry, oxygen-free nitrogen gas, using Schlenk techniques, with solvents purified as described previously.l12 The starting materials [AuCl(PR3)] (R = PPh3, PEt3) and [AuC1(SMe2)1,17[CUC~(PP~&],~~ [TlM(SC&'5)4Cp],1'2 [MCl3(C0)2~ Cp], (M = Mo, W),19and M'(SCeF5) ( M = Au, Ag, C U )were prepared by literature methods. Compounds HAuC14, C6F5SH, PPh,PEt3, Ph2P(C&)&P ' h2 (dppe),Ph2P(CHMPh2(dppp), [N(PPh3)2lC1, and Tl(02CMe) were obtained commercially (Strem or Aldrich) and used as supplied. IR spectra were recorded on a Perkin Elmer 580 or FT-1600 spectrometer,and W h i s spectra were recorded on a Shimadzu W-240 spectrometer. ' H, 19F,and 31P{'H} NMR spectra were recorded
3504 Organometallics, Vol. 14,No.
7,1995
Davidson et al.
Figure 3. Molecular structure of complex 6 (ORTEP 30% probability elipsoids). Labels for t h e F and H atoms a r e t a k e n from the carbon atom t o which they are bonded.
Reaction of [mo(SC86)4Cp]with [AuCl(PPhdl. Complex l a (100 mg, 0.09 mmol), [AuCl(PPh3)1(44mg, 0.09 mmol) and PPh3 (68 mg, 0.26 mmol) were stirred in dichloromethane (40 cm3)at room temperature for 15 min giving a dark cloudy solution. The mixture was filtered, hexane (10 cm3)was added to the filtrate, and the resulting solution was concentrated in vacuo to give red crystals of [AU(PP~~)~][MO(SC$~)&~M.~CH~C12 (2a) (72 mg, 41%). Anal. Found: C, 50.5; H, 2.8; S, 6.2. Calcd for C~3.5H51C1F20P3S&~Mo: C, 50.5; H, 2.6; S, 6.5. IR (CH2C12), C6F5 vibrations: 1507 (s) and 1478 (s) cm-'. NMR: lH {(CD3)2CO, 19 "C}, 6 7.2-7.6 (m, 45H, C6H5), 5.25 (s, 5H, C5H5) and 5.23 (s, lH, CHzC12) ppm; 19F{(CD3)2C0,19 "C}, 6 -130.6 (br, d, J = 20.3 Hz, 8 o-F), -160.6 (t, J = 20.6 Hz, 4 p-F) and -166.2 (m, 8 m-F); {(CD3)2CO,-90 "C}, -127.8 (dd, J = 28.9, 6.8 Hz, 4 0-F), -132.7 (dd, J = 27.9, 6.2 Hz, 4 0-F), -158.6 (t, J = 21.9 Hz, 4 p-F), -164.1 (4,J = 23.0 Hz, 4 J = 23.6 Hz, 4 m-F); 31P((CD3)2C0,20 m-F), and -165.0 (4, "C) 6 37.7 (br s) ppm. Reaction of ["lMo(SC85)4Cp)with [AuCl(PEts)l. Complex l a (100 mg, 0.09 mmol), [AuCl(PEt3)1(30mg, 0.09 mmol) and PEt3 (34 mg, 0.29 mmol) were stirred in dichloromethane (40 cm3)under nitrogen a t room temperature for 30 min giving a n orange cloudy solution. The mixture was filtered, hexane (10 cm3) was added, and the resulting solution was concentrated in vacuo to give red crystals of [Au(PEt3)3][Mo(SCsF5)4Cp] (3a) (70 mg, 54%). Anal. Found: C, 37.0; H, 3.0. Calcd for C47H&4P3F20MoAu: C, 37.4; H, 3.3. IR (CH2C12): C6F5 vibrations at 1508 (s) and 1477 cm-'. NMR: 'H (CDC13, 20 "C) 6 5.29 (s, 5H, C5H5), 2.1-1.8 (br m, 18H, CHd, and 1.41.0 (br m, 27H, CH3); 19F(CD2C12, 18 "C) 6 -131.3 (br d, J = 20.8 Hz, 8 o-F), -160.1 (m, 4 p-F), and -165.9 (m, 8 m-F); (CD2C12, -80 "C), -129.3 (dd, J = 29,2,6.4 Hz, ~ o - F )-133.1 , (dd, J = 27.7, 6.0 Hz, 4 0-F), -157.5 (t,J = 22.4 Hz, 4 p-F), -163.2 (-t, J = 24.5 Hz, 4 m-F), and -164.6 (-4,J = 23.7 Hz, 4 m-F); 31P(CD2C12, 18 "C) 6 35.9 (9); (CDzC12, -80 "C), .As .no -1'3s .A0 -111s ./so .,b .A0 .llM .I:P vr" 39.6 (8);19F{(CD3)2C0,20 "C} 6 -130.6 (dd, J = 26.0, 6.0 Hz, -160.9 (m, 4p-F), and -166.4 (m, 8 m-F); 31P((CD3)2Figure 4. 19FNMR spectra of [ A u ( P P ~ ~ ) ~ I [ W ( S C ~ F ~ ) & 8~ o-F), I CO, 20 "C) 6 35.6 (br s) ppm. in CDZC12: (a) 20 "C; (b) -20 "C; (c) -30 "C; (d) -47 "C; (e) Reaction of [mw(SCa6)4Cp]with [AuCl(PPhdl. Com-80 "C. plex lb (100 mg, 0.08 mmol), [AuCUPPhd] (45 mg, 0.09 mmol) a t variable temperatures on a Bruker WP 200 SY instrument and PPh3 (78 mg, 0.30 mmol) were stirred in dichloromethane operating a t 200.13, 188.31, and 80.32 MHz, respectively, (40 cm3)under nitrogen a t room temperature for 15 min giving using SiMe4, CC13F, and 85%aqueous H3P04 a s references (6 a cloudy solution. The mixture was filtered, hexane (10 cm3) 0.0 ppm). Elemental analyses were carried out a t UMIST, was added, and the resulting solution was concentrated in Manchester, U.K. vacuo to give yellow crystals of [AU(PP~~)~I[W(SC~F~)~C~] 2b (17) See: Puddephatt, R. J. The Chemist0 of Gold; Elsevier: (100 mg, 62%). Anal. Found: C, 49.2; H, 2.0; S, 6.3. Calcd Amsterdam, 1978. Puddephatt, R. J.; Treurnicht, I. J. Organomet. for C ~ ~ H ~ O F ~ O P ~ S C, Q ~49.1; U W H, : 2.5; S, 6.3. IR (CHzC12): Chem. 1967,319,129. C6F5 vibrations a t 1508 (s) and 1479 (s) cm-'. NMR: 'H (18)Riechle, W.T.Inorg. Chim. Acta 1971,5 , 325. (19)Green, M. L. H.; Lindsell, W. E. J. Chem. Soc., A 1967,686. ((CD&CO, 20 "C) 6 7.2-7.6 (m, 45H, C6H5) and 5.17 (s, 5H,
[ A u ( P P ~ ~ ) ~ ~ [ M o ( S Cand ~ ~[ C ) FU ~ ( P) P~~~~ /) ~ ~ [ M O ( S C ~ F S ) ~Organometallics, ( ~ ~ ~ - C ~ H ~ ) ]Vol. 14, No. 7, 1995 3505
Table 6. Coalescence Temperatures (T,)and Derived AG* values from ortho and meta lgF NMR Resonances of CsFa Groups of PentafluorobenzenethiolatoComplexes in Acetone or Dichloromethane Solutions acetoned6
Tc (K) 203 208 224
[AU(PP~~)~I[W(SC~F~)~C~I(~~) meta-lgF ortho-lgF meta-lgF ortho-lgF
[Au(PEt3)a][W(SCsF5)4Cp](3bY
a
Estimated error
