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

The reaction of CuSO4·5H2O, 4-chloro­pyrazole (4-Cl-pzH) and tri­ethyl­amine (Et3N) in di­methyl­formamide (DMF) produced crystals of di­aqua­hexa­kis­(μ-4-chloro­pyrazolato-κ2N:N′)bis­(N,N-di­methyl­formamide)di-μ3-hydroxido-bis­(μ4-sulfato-κ4O:O′:O′′:O′′)hexa­copper(II) N,N-di­methyl­formamide tetra­solvate dihydrate, [Cu3(OH)(SO4)(C3H2ClN2)3(C3H7NO)(H2O)]2·4C3H7NO·2H2O. 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 CuII atoms are bridged by μ-pyrazolate groups and a central μ3-OH group, and are coordinated by terminal sulfate, H2O 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).