ESR <i>g</i>-ANISOTROPY INVERSION OBSERVED FOR Cu(II)-CROWN ETHER COMPLEX IN SOLUTION

Abstract

Abstract CuCl2 solubilized by Benzo-15-crown-5 in dry CHCl3 showed the anomalous g-anisotropy inversion (g|| &amp;lt;g⊥) in the ESR spectrum. The spin Hamiltonian parameters determined were g||=1.995, g⊥=2.294 and |A|||=129.8×10−4 cm−1. Based on the ESR parameters, the bonding parameters of Cu(II) were calculated with application of the Swalen’s method. A weak bonding in the xy-plane of the paramagnetic site was assumed between the metal and the ligands, and a perturbation on the Cu(II) positive hole appears mainly due to the crystal field working along the z-axis, and the unpaired electron was suggested to occupy the dz2 orbital at the ground state.