D-Orbital orientation in a dimer cobalt complex: Link to magnetic properties?

Abstract

The experimental charge-density distribution of the dinuclear cobalt(II) complex [Co 2(sym-hmp) 2](BPh 4) 2·2H 2O·2C 3H 6O was determined at 100 K. When decreasing the temperature, the magnetic susceptibility of this complex deviates from Curie law because of anti-ferromagnetic exchange interactions, but the susceptibility increases sharply at low temperature (< 20 K). To explain this magnetic behaviour a tilt angle between the Co-atom environments was previously theoretically predicted. The structure and experimental charge density determined in this study show a tilt angle. The calculated value, based on the 100 K experimental d-orbital model, is in agreement with the theoretical one. © 2011 International Union of Crystallography Printed in Singapore all rights reserved.