REACTIONS OF MONOCYCLOPENTADIENYL PENTAFLUOROBENZENETHIOLATO COMPLEXES OF MOLYBDENUM AND TUNGSTEN WITH GROUP-11 METAL DERIVATIVES - CRYSTALAND MOLECULAR-STRUCTURES OF [AU(PPH(3))(3)][MO(SC6F5)(4)(ETA(5)-C5H5)] AND [CU(PPH(3))(3)][MO(SC6F5)(4)(ETA(5)-C5H5)]

Displacement of coordinated Tl(I) as TlCl from [TlM(SC6F5)(4)Cp] (M = Mo, W; Cp = mu(5)C(5)H(5)) by gold complexes [AuCl(PR(3))] (R = Ph, Et ) in dichloromethane or acetone solution affords ionic products [Au(PR (3))(3)][M(SC6F5)(4)Cp], isolable in higher yields from reactions carr ied out in the presence of three molar equiv of free phosphine, PR(3). Ligand exchange between [Au(PPh(3))(3)][M(SC6F5)(4)Cp] and diphosphin es produces derivatives [Au(Ph(2)P(CH2)(n)PPh(2))(2)][M(SC6F5)(4)Cp] { n = 2 dppe (4); n = 3 dppp (5); M = Mo, W). A related reaction of [CuC l(PPh(3))(3)] and [TlMo(SC6F5)(4)Cp] forms the copper derivative [Cu(P Ph(3))(3)][Mo(SC6F5)(4)Cp] as the major product. Attempts to isolate d erivatives with group 11 metal cations coordinated by anions [M(SC6F5) (4)Cp](-) have been unsuccessful. Molecular structures of crystalline bimetallic species [M'(PR(3))(3)][Mo(SC6F5)(4)Cp]. 0.5CH(2)Cl(2) {M' = Au (2a), Cu (6)} have been determined by X-ray diffraction and are es sentially isomorphous. Both contain approximately trigonal-planar [M'( PPh(3))(3)](+) cations with P-Au-P angles of 123.83(5)degrees, 122.28( 5)degrees, and 113.62(5)degrees and an average Au-P distance 2.386(2) Angstrom or P-Cu-P angles 121.24(7)degrees, 123.44(8)degrees and 115.1 1(7)degrees and an average Cu-P bond length 2.295(2) Angstrom, respect ively. The discrete anions [Mo(SC6F5)(4)Cp](-) 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) Angstrom, respectively. Spectroscopic studies of complexes 4 and 5 support ionic constitutions with four-coordinate d [Au((Ph(2)P(CH2)(n)PPh(2))2](+) cations. Variable temperature F-19 N MR studies of anions [M(SC6F5)4Cp](-) of gold derivatives give barrier s to fluxional rotation/inversion of SC6F5 groups, Delta G(double dagg er) ca. 40-41 kJ mol(-1) (208-228 K), M = Mo, or Delta G(double dagger ) ca. 43-44 kJ mol(-1) (223-245 K), M = W, comparable with Delta G(dou ble dagger) values for salts [N(PPh(3))(2)][M(SC6F5)(4)Cp], which are essentially independent of solvent (CD2Cl2, (CD3)(2)CO, or C6D5CD3), i n Contrast to barriers for coordinated species [TlM(SC6F5)(4)Cp].