A second tetragonal polymorph of bis(tetra-n-butylammonium) tetrakis[chloro(μ3-sulfido)copper(I)]molybdate(VI)

Abstract

The title compound, bis­(tetra-n-butyl­ammonium) tetra­chloro­tetra-μ3-sulfidotetracopper(I)molybdenum(VI), (C16H36N)2[MoS4(CuCl)4], has been obtained in a second polymorphic form. The anion, in which four of the six S⋯S edges of the central MoS4 tetrahedron are bridged by CuCl neutral molecular units to give a planar pentanuclear MoCu4 framework, is disordered on a crystallographic fourfold rotation axis, requiring equal occupancy of two sets of four positions for the S atoms. There is additional disorder as a result of 8.2 (2)% substitution of Cl by Br, arising from tetra-n-butyl­ammonium bromide used in the synthesis. Copper has distorted trigonal planar coordination, involving two μ3-S atoms and a terminal halogen atom. The two independent cations lie on positions of symmetry \overline 4.