Synthetic And Spectral Studies On Copper(Ii) Chloride And Bromide Complexes With Isomeric Aminobenzonitriles

Syntheses of the coordination compounds formed by the interaction of copper(II) chloride and bromide with 2-, 3- and 4- amino-benzonitriles (ABN) has been described. The compounds isolated have been characterized on the basis of elemental analyses, electrical conductance, magnetic moments, electronic and electron spin resonance studies in the solid and DMF solution states to study the steric effects caused by the nitrile substitution, at different positions, on the nature of copper(II) - nitrogen bond. The spectra of the complexes for a particular halide are closely comparable suggesting that they have the same local symmetry. Analysis of the polycrystalline ESR data indicate rhombic symmetry for the chloro complexes. Axial symmetry is, however, suggested for the bromo complexes. The solution ESR as well as electronic spectral studies show the interaction of solvent (DMF) molecules with copper(II) ion in the axial plane. Various spin-Hamiltonian parameters calculated from the ESR data indicate the presence of unpaired electron in the d(x2-y2) orbital of the copper(II) ion. It is shown that the spin-Hamiltonian parameters are practically unaffected by the steric effects and are almost similar for all the complexes.