Crystal Structure and Magnetic Property of Cubane Tetranuclear Copper(II) Complex with Ferromagnetic Coupling

Abstract

The magnetic susceptibility measurement down to the liquid helium temperature and the single-crystal X-ray analysis of alkoxo-oxygen bridged tetranuclear copper(II) complex [CuL]₄ have been performed, where H₂L is a tridentate ligand derived from condensation of 3-ethoxymethylene-2,4-pentanedione and 2-aminoethanol. The magnetic data demonstrated that the four unpaired electrons of the four copper(II) ions are ferromagnetically coupled, the ground spin state of the cubane molecule being S=2. The structural analysis has confirmed several structural features, i.e., the distorted Cu₄O₄ cubane structure, the square pyramidal coordination geometry, nearly perpendicular arrengement between adjacent basal coordination planes, and inequivalent Cu–O bond distances.