Mono and Tetranuclear Gold(I) Complexes of Tris(1-benzylimidazole-2-yl)-phosphine

The reaction of tris(1-benzylimidazole-2-yl)phosphine, (Bzim)(3)P, 1. with Ph3AsAuCl in 1:1 stoichiometric ratio produced (Bzim)(3)PAuCl, 2. The reaction of (Bzim)(3)PAuCl with NaAuCl4 in 1: 1 stoichiometry in dichloromethane gives an orange-yellow crystalline tetranuclear gold(l) cluster [{mu-N,N'-(Bzim)(3)PAuCl}(2)Au-2][AuCl2][AuCl4], 3. Complex 4, [{mu-N,N'-(BZim)(3)PAuCl}(2)Au-2][AuCl2](2) is formed when the reaction stoichiometry of (Bzim)(3)PAuCl and AuCl4- is 2:1. The crystal structure of 3 shows the formation of a 12-membered macrocycle with Au center dot center dot center dot Au distances of similar to 3.0 angstrom. The structures of (Bzim)(3)PAuCl and 3 show Au center dot center dot center dot H-C interactions ranging from 2.57 to 2.95 angstrom. Complex 2 crystallizes in the monoclinic space group P2(1)/n (Z=4), a = 9.1927(5), b = 13.528(2), C = 22,995(2) angstrom, and beta = 94.537(5)degrees: Complex 3 crystallizes in the monoclinic space group P2(1)/c (Z = 4), a = 13.785(4), b = 21.426(6), c = 25.203(8) angstrom, and beta = 96.51(6)degrees.