Alkoxo- and carboxylato-bridged hexanuclear copper(II) complex: Synthesis, structure and magnetic properties

Reaction of copper(II) nitrate trihydrate with N,N-dimethylethanolamine (dmea) and pivalic acid in methanol led to the hexanuclear copper(II) complex Cu6(η1:μ2-C4H10NO)4(η1:η1:μ2-C5H9O2)4(η1:μ1-C5H9O2)2(μ3-OH)2 (1). The crystal structure of 1 indicates that hexametallic centers are bridged by the μ3-alkoxo, dmea oxygens, and the μ2-dicarboxylato oxygen atoms of pivalate ions. Furthermore, in the asymmetric unit, three types of copper ions have been found labeled as Cu1, Cu2 and Cu3. The Cu2 takes a distorted octahedral shape, whereas Cu1 and Cu3 adopt square pyramidal geometries. The complex 1 shows strong antiferromagnetic interactions through the oxo groups within the dimeric units (J = − 82.6 to − 25.8 cm− 1) and weak antiferromagnetic couplings between the dimers (J = − 10.9 and 0.8 cm− 1).