SYNTHESIS AND CHARACTERIZATION OF COPPER(I) AND SILVER(I) TELLUROLATES AND SELENOLATES - THE X-RAY CRYSTAL-STRUCTURES OF (CU[SEC(SIME3)3]PCY3)2 AND THE HOMOLEPTIC SILVER SELENOLATE AG4[SEC(SIME3)3]4

Homoleptic copper(I) and silver(I) selenolates of empirical formula M [SeC(SiMe3)3] (M = Cu, Ag) were prepared by reaction of (DME)LiSeC(SiM e3)3 (DME = 1,2-dimethoxyethane) with CuCl or AgNO3 in DME. At -20-deg rees-C, Ag4[SeC(SiMe3)3]4 crystallized from concentrated hexane soluti on as a hexane solvate in the monoclinic space group P2(1)/c with a = 17.848(4) angstrom, b = 20.017(3) angstrom, c = 23.997(3) angstrom, be ta = 92.90(2)degrees, V = 8563(4) angstrom3, d(calcd) = 1.47 g cm-3, a nd Z = 4. Reaction of CuCl with (DME)LiSeC(SiMe3)3 in benzene afforded the salt [Li(DME)2]-{Cu[SeC(SiMe3)3]2}. Related reactions between CuB F4(PCy3)2 or AgBr(PCy3)2 and (THF)2LiTeC(SiMe3)3 or (DME)LiSeC(SiMe3)3 in either toluene or diethyl ether gave the tricyclohexylphosphine co mplexes M(ER)(PCy3) (E = Se, Te; R = C(SiMe3)3). Cu[SeC(SiMe3)3](PCy3) is dimeric in the solid state; it crystallized from hexane at -20-deg rees-C in the space group P2(1)2(1)2(1) with a = 12.039(2) angstrom, b = 14.800(2) angstrom, c = 37.615(6) angstrom, V = 6702(3) angstrom3, d(calcd) = 1.30 g cm-3, and Z = 4.