DINUCLEAR GOLD(II) COMPLEXES CONTAINING 2 DIFFERENT BRIDGING LIGANDS - CRYSTAL-STRUCTURE OF [AU-2(MU-(CH2)(2)PPH(2))(MU-S2CN(CH(2)PH)(2))BR-2]

The oxidative addition of halogens to [Au-2{mu-(CH2)(2)PPh(2)}{mu-(PPh(2))(2)Y}]ClO4 (Y = CH2 or NH) or [Au-2{mu-(CH2)(2)PPh(2)}(mu-S(2)CNR(2))] (R = Me, Et or CH(2)Ph) leads to the gold(II) derivatives [Au-2{mu-(CH2)(2)PPh(2)}{mu-(PPh(2))(2)Y}X(2)]ClO4 or [Au-2{mu-(CH2)(2)PPh(2)}(mu-S(2)CNR(2))X(2)] (X = Cl, Br, or I), respectively. The reaction of [Au-2{mu-(CH2)(2)PPh(2)}(mu-S(2)CNR(2))X(2)] with Ag(OClO3)(PPh(3)) or Ag(C6F5) gives the mixed-valence gold(I)-gold(III) complexes [Au-2{(CH2)(2)PPh(2)}(S(2)CNR(2))(PPh(3))(2)](ClO4)(2) (R = Me, CH(2)Ph) or [Au-2{(CH2)(2)PPh(2)}(S(2)CNMe(2))(C6F5)(2)], respectively. The structure of [Au-2{mu-(CH2)(2)PPh(2)}{mu-S2CN(CH(2)Ph)(2)}Br-2] has been determined by a single-crystal X-ray diffraction study. It crystallizes in the space group P (1) over bar with a = 11.937(3) Angstrom, b = 12.105(2) Angstrom c 12.568(2) Angstrom, alpha = 80.04(2)degrees, beta = 81.77(2)degrees, gamma = 71.58(2)degrees, and Z = 2. The two gold atoms are part of an eight-membered ring with a twisted conformation; both exhibit a square-planar geometry with a short gold-gold bond of 2.5653(10) Angstrom.