Reactivity of metal(0) dithiocarbamato carbonyl complex [M(CO) 4(S 2CNEt 2)] − (M = Mo, W): a new synthesis and structure of a mixed-metal MoWS complex [Et 4N] 2[(OC) 4MoS 2WS 2

Abstract

The reaction of molybdenum(0) dithiocarbamato carbonyl complex [Et 4N][Mo(CO) 4(S 2CNEt 2)] with tetraethylammonium tetrathiotungstate [Et 4N] 2[WS 4] in acetonitrile or methanol affords the dinuclear mixed-metal MoWS complex, [Et 4N] 2 − [(OC) 4MoS 2WS 2] ( 1). 1 was characterized by routine elemental analysis and spectroscopy and its structure was studied by X-ray crystallography. 1 crystallizes in the orthogonal, space group Pbcm with a = 18.453(2), b = 12.004(2), c = 13.494(3) Å; V = 2988.9 Å 3; Z = 4; D c = 1.73 g/cm 3; R 1 = 0.032 and R 2 = 0.041 for 1971 independent reflections ( I > 3σ( I)). The structure of the anion of 1 is composed of an octahedron around the molybdenum atom and a tetrahedron with the tungsten atom in the center sharing an edge whcih is the line between the two bridged sulfur atoms. The Mo···W bond distance is 3.0330(8) Å and the bimetallic center MoS 2W is planar with the MoSW angles of 78.74(6)° and 78.42(7)°. The longer average bond distances of MoCO and WS indicate the existence of a Mo → WS 4 electron delocalization in 1 which is similar to the charge transfer in the linear FeMoS cluster compounds. The new route to synthesize 1 is also discussed.