EPR spectra and characteristics of metal-ligand bond in complexes of divalent copper with some amino acids

Electron paramagnetic resonance spectra were obtained in low-temperature glasses for a series of copper complexes with amino acids: glycine, - and -alanine, valine, leucine, histidine, serine. The ionicity coefficients ² and ₁ ² of the metal-ligand bond were calculated from the spin Hamiltonian constants and from optical data. The results are compared with the stability of the investigated complexes.