Bis(tetraethylammonium) bis(dimethylformamide)tetrakis(μ-N,2-dioxidobenzene-1-carboximidato)pentacopper(II)

Abstract

The title compound, (C8H20N)2[Cu5(C7H4NO3)4(C3H7NO)2], abbreviated as (TEA)2[CuII(12-MCCuII N(shi)-4](DMF)2 [where TEA is tetra­ethyl­ammonium, shi3− is salicyl­hydroximate (or N,2-dioxidobenzene-1-carboximidate) and DMF is N,N-dimethyl­formamide], contains five CuII ions. Four of the CuII ions are members of a metallacrown ring (MC), while the fifth CuII is bound in a central cavity. Two of the ring CuII ions are five-coordinate with distorted square-pyramidal geometry. The coordination sphere is composed of two shi3− ligands and one DMF mol­ecule. The other two ring CuII ions and the central CuII ion are four-coordinate with square-planar geometry. The coordination spheres of these ions are only composed of shi3− ligands. The charge of the [CuII(12-MCCuII N(shi)-4]2− unit is balanced by two uncoordinated TEA+ countercations. The structure shows severe static disorder with the metallacrown, the tetra­ethyl­ammonium cations and the DMF solvent mol­ecule all disordered over each of two mutually exclusive sites, with occupancy rates for the major moieties of 0.6215 (6) for the metallacrown, 0.759 (3) for the tetra­ethyl­ammonium ion and 0.537 (6) for the DMF mol­ecules. The metallacrown unit is located on a crystallographic inversion center and disordered about a non-crystallographic twofold axis. The DMF mol­ecule and the tetra­ethyl­ammonium ion are disordered about a non-crystallographic twofold axis and pseudo-inversion center, respectively.