Studies of EPR and ENDOR spectra of14N and15N label bis(2-hydroxyacetophenyl ketoxime)-63Cu(II) and-65Cu(II) complexes in disordered system

The EPR spectra of isotopic label bis(2-hydroxyacetophenyl ketoxime)-Cu(II) [N?Cu-HAP] complexes, such as¹⁴N?⁶³Cu-HAP,¹⁵N?⁶³Cu-HAP and¹⁴N?⁶⁵Cu-HAP in frozen THF solution below 77 K, and their ENDOR spectra in frozen DMSO/EtOH (5∶1) solution below 20 K were studied. The exact values of the components ofg-tensor, of hyperfine tensors of copper isotopes, and of superhyperfine interaction tensors of copper with nuclei of nitrogen isotopes and¹H nuclei, and of the¹⁴N nuclear quadrupolar moment coupling tensor were obtained. The bond parameters α, β, δ, γ and the corresponding energy levels of N?Cu-HAP complexes were calculated by using EPR and ENDOR data. It was shown that the unpaired, electron is delocalized not only to the nearest N atom but also to the H atom, of ligands, which is more far from the Cu ion.