cyclo-Tetrakis(μ-3-acetyl-4-methyl-1H-pyrazole-5-carboxylato-κ4N2,O3:N1,O5)tetrakis[aquacopper(II)] tetradecahydrate

Abstract

The title compound, [Cu4(C7H6N2O3)4(H2O)4]·14H2O, a tetranuclear [2 × 2] grid-type complex with S4 symmetry, contains four CuII atoms which are bridged by four pyrazolecarboxylate ligand anions and are additionally bonded to a water molecule. Each CuII atom is coordinated by two O atoms of the carboxylate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carboxylic acid and one O atom of a water molecule. The geometry at each CuII atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O—H...O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.