Tris(tetraethylammonium) tris(μ3-sulfido)bis[bromocopper(I)][dibromocopper(I)]oxomolybdate(VI) acetone solvate

Abstract

The title compound, (NEt4)3[(MoOS3)(CuBr)2(CuBr2)]·(CH3)2CO, contains a central pseudo-tetrahedral MoOS32− unit with Cu atoms bridging all three S⋯S edges while the Mo=O bond remains terminal. The Mo, 3 Cu and three triply bridging S atoms occupy seven of the vertices of a distorted cube, the vertex opposite Mo being vacant. Two of the Cu atoms carry one terminal halogen atom each and have distorted trigonal planar coordination, while the third carries two and has distorted tetrahedral coordination. One of these two halogen atoms on the third Cu atom has a secondary interaction with one of the other Cu atoms, so it may be considered as semi-bridging. Three of the four halogen sites show disorder as a result of minor substitution of Cl for Br, the semi-bridging halogen atom being purely or essentially Br. This semi-bridging type of halogen is unprecedented in MOS3Cu3Xn cluster anions.