Syntheses, reactions and spectroscopic properties of Mo(W)-Cu-S cluster compounds, and crystal structure of (Et4N)(4)[WS4Cu10Br12]

The synthetic reactions and spectroscopic studies of molybdenum (tungsten)-copper-sulfur cluster compounds, which can be prepared by the stepwise or unit construction reactions through the successive addition of Cut (L = Cl, Br, R(2)dtc) across six edges or four faces of MS4 (M=Mo, W) tetrahedra, are described. A series of Mo(W)-Cu-S cluster compounds, (Et4N)(2)[MoCu2S4(S2CNEt2)(2)] (1) (Et4N)(2)-[MoCu2S3O(S2CNC4H8)(2)] (2), [MoCu2S4(dppe)(2)] (3) (dppe = bis(diphenylphosphine)ethane), (Et4N)(2)[MoCu3S4(S2CNEt2)(3)] (4), (Et4N)(2)[Mo2Cu4S8(S2CNEt2)(2)] (5), (Et4N)(2)[Mo2Cu4S6O2(S2CNC4H8)(2)] (6), [Mo2Cu4S8(dppm)(2)] (7), [Mo2Cu4S6O2(dppm)(2)] (8) (dppm = bis(diphenylphosphine)methane), (Et4N)(4)[MoS4Cu10Br12] (9), (Et4N)(4)[WS4Cu10Br12] (10), have been prepared and characterized by IR and Mo-95 NMR spectra. The polynuclear W-Cu cluster compound (Et4N)(4)[WS4Cu10Br12] (10) is characterized by single crystal X-ray diffraction analysis. The anion structure consists of a central WS4 moiety, an octahedral Cu, and a tetrahedral Cu-4 array. The average W-Cu and W-S distances are 2.726(8) and 2.247(7) Angstrom and the average angles of S-W-S, S-Cu-S and S-Cu-Br are 109.5(3), 104.1(4) and 112.6(3)degrees, respectively.