Synthesis, characterization and crystal structures of binuclear cluster compounds [Me4N]2[TS4(AgCN)] (T = Mo, W)

Red-brown and orange-yellow crystals of [Me4N]2[MoS4(AgCN)] and [Me4N]2[WS4(AgCN)], respectively, have been obtained from the reactions of tetramethyl ammonium thiomolybdate and tungstate, [Me4N]2[TS4] (T = Mo, W), with AgCN in acetonitrile at room temperature. The complex anions have been characterized by infrared and mass spectroscopy. The crystal structures were determined from single crystal diffractometer data. The two compounds are isostructural, with space group P21. The lattice parameters are: a = 6.287(2)Ä, b = 7.3740(7)Ä, c = 20.602(8)Ä, beta = 92.59(2)° (molybdenum complex), and a = 6.313(4)Ä, b = 7.384(4)Ä, c = 20.592(1)Ä, beta = 92.60(2)° (tungsten complex). The crystal structures are characterized by a pseudo-hexagonal packing of stacks of the binuclear complex anions, [TS4(AgCN)]2-. The influence of the packing on the silver coordination is discussed.