Structure and magnetic properties of dinuclear and trinuclear copper(II) triethanolamine complexes

Abstract

In continuation of our interest in coordination chemistry of copper(II) complexes, novel di- and tri-nuclear Cu(II)-triethanolamine (TEA) complexes have been isolated and characterized by means of X-ray diffraction, IR spectroscopy, EPR measurements and wavefunction-based quantum chemistry calculations. In these complexes, one of the TEA hydroxyl group bridges two adjacent copper atoms. The magnetic coupling constants (J) of both complexes have been evaluated by means of difference dedicated configuration interaction (DDCI) calculations, using a simplified model of the X-ray determined geometry (without the external phenyl or furan groups). As in many other oxo-bridged Cu complexes, the J values are correlated to the value of Cu-O-Cu angle, which determines the Cu and O orbitals overlap driving the ferro and antiferromagnetic coupling between Cu neighbours via super-exchange through the oxygen orbitals. Magnetic susceptibility measurements validate the theoretical findings