ESR STUDY OF SOME CU(II)-4-SUBSTITUTED-2-THIAZOLYLHYDRAZONE COMPLEXES

The Cu(II) complexes with 2-N-acetyl-salicylidene-hydrazino-4-chlor-me thyl thiazole (L-I) and 2-N-acetyl salicylidene-hydrazino-4-thiazolyl acetic ester (L-II) were prepared and investigated by ESR measurements . The powder ESR spectrum at room temperature of CuLIICl is quasi-isot ropic (g = = 2.113), while for CuLIICl is characteristic of monomeric species with axial symmetry (g(parallel to) = 2.234, g(perpendicular t o) = 2.073). The isotropic ESR spectra of the CuLCl compounds in DMSO solution suggest the presence of pseudo-tetrahedral monomeric species. The anisotropic spectra were obtained for adsorbed CuLCl DMSO solutio ns on NaY zeolite. The parallel hyperfine structure shows the coexiste nce of two magnetic nonequivalent monomeric species. The estimation of some LCAO-MO coefficients using Kivelson and Neiman's approximation r eveals a dominant ionic character for copper-ligand bonds.