Sulfate-bridged dimeric trinuclear copper(II)–pyrazolate complex with three different terminal ligands

The reaction of CuSO(4)·5H(2)O, 4-chloro­pyrazole (4-Cl-pzH) and tri­ethyl­amine (Et(3)N) in di­methyl­formamide (DMF) produced crystals of di­aqua­hexa­kis­(μ-4-chloro­pyrazolato-κ(2) N:N′)bis­(N,N-di­methyl­formamide)di-μ(3)-hydroxido-bis­(μ(4)-sulfato-κ(4) O:O′:O′′:O′′)hexa­copper(II) N,N-di­methyl­formamide tetra­solvate dihydrate, [Cu(3)(OH)(SO(4))(C(3)H(2)ClN(2))(3)(C(3)H(7)NO)(H(2)O)](2)·4C(3)H(7)NO·2H(2)O. The centrosymmetric dimeric molecule consists of two trinuclear copper–pyrazolate units bridged by two sulfate ions. The title compound provides the first example of a trinuclear copper–pyrazolate complex with three different terminal ligands on the Cu atoms, and also the first example of such complex with a strongly binding basal sulfate ion. Within each trinuclear unit, the Cu(II) atoms are bridged by μ-pyrazolate groups and a central μ(3)-OH group, and are coordinated by terminal sulfate, H(2)O and DMF ligands, respectively. Moreover, the sulfate O atoms coordinate at the apical position to the Cu atoms of the symmetry-related unit, providing square–pyramidal coordination geometry around each copper cation. The metal complex and solvent mol­ecules are involved in O—H⋯O hydrogen bonds, leading to a two-dimensional network parallel to (10-1).