EPR STUDIES OF COPPER(II) COMPLEXES OF α-AMINO ACIDS IN HOST CRYSTALS OF THE CORRESPONDING POLYCRYSTALLINE ZINC(II) COMPLEXES: METAL-LIGAND BONDS AND MOLECULAR STRUCTURE

The coordinative bonds in the copper(II) complexes of twelve α-amino acids have been studied. Molecular orbital coefficients have been calculated according to D4th symmetry, using the EPR spectral data on the corresponding polycrystalline copper(II)-doped zinc(II) complexes in conjunction with the electronic transition energies obtained by Gaussian analysis of the reflectance spectra of the pure copper (II) compounds. Multiple linear regression analysis has been carried out between the MO coefficients and various structural data. It has been established that (a) with increasing covalency of the in-plane Δ bond, the covalency of the in-plane bond decreases, and (b) the greater the deviation from elongated octahedral towards square-pyramidal geometry, the more covalent the out-of-plane bond becomes.