Use of Cu2+ as a metal ion probe for the EPR study of metal complexation sites in the double sulfite (Cu2SO3)-S-1 center dot(CdSO3)-S-II center dot 2H(2)O

摘要

An evaluation was made of the presence of paramagnetic ions in the host lattice of (Cu2SO3)-S-I. (CdS3)-S-II.2H(2)O by the electron paramagnetic resonance (EPR) technique, using copper(H) ions as paramagnetic probes. The existing M-1 and M-II complexation sites in the double sufite structure were successfully differentiated. The results indicate that the (Cu2SO3)-S-I (CdSO3)-S-II.2H(2)O structure was doped with Cu-II ions in the two metal ion substitutional positions. The low g(parallel to)/A(parallel to) ratio for the Cu-II probe in the distorted octahedral site resulted from the interaction of copper ions with oxygen donor atoms in a distorted tetragonal environment, with elongation of the molecule in the z direction. The very low value of the A(33) hyperfine coupling constant was explained considering the admixture of the d(x)(-y)(2)(2) and d(2)(2) orbitals and the almost trigonal pyramidal structure of the other site.