Bis(tetra-ethyl-ammonium) bis-(dimethyl-formamide)-tetra-kis-(μ-N,2-dioxido-benzene-1-carboximidato)penta-copper(II).

The title compound, (C(8)H(20)N)(2)[Cu(5)(C(7)H(4)NO(3))(4)(C(3)H(7)NO)(2)], abbreviated as (TEA)(2)Cu(II)(12-MC(Cu(II) ) (N(shi))-4(2) [where TEA is tetra-ethyl-ammonium, shi(3-) is salicyl-hydroximate (or N,2-dioxidobenzene-1-carboximidate) and DMF is N,N-dimethyl-formamide], contains five Cu(II) ions. Four of the Cu(II) ions are members of a metallacrown ring (MC), while the fifth Cu(II) is bound in a central cavity. Two of the ring Cu(II) ions are five-coordinate with distorted square-pyramidal geometry. The coordination sphere is composed of two shi(3-) ligands and one DMF mol-ecule. The other two ring Cu(II) ions and the central Cu(II) ion are four-coordinate with square-planar geometry. The coordination spheres of these ions are only composed of shi(3-) ligands. The charge of the Cu(II)(12-MC(Cu(II) ) (N(shi))-4 unit is balanced by two uncoordinated TEA(+) countercations. The structure shows severe static disorder with the metallacrown, the tetra-ethyl-ammonium cations and the DMF solvent mol-ecule 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 tetra-ethyl-ammonium ion and 0.537 (6) for the DMF mol-ecules. The metallacrown unit is located on a crystallographic inversion center and disordered about a non-crystallographic twofold axis. The DMF mol-ecule and the tetra-ethyl-ammonium ion are disordered about a non-crystallographic twofold axis and pseudo-inversion center, respectively.