Abstract: A better resolution of ESR spectra of labelled ⁶³Cu-¹⁴N-HAP,⁶⁵Cu-¹⁴N-HAP, ⁶³Cu-¹⁵N-HAP, ⁶⁵Cu-¹⁵N-HAP and Cu-¹⁵N-HAP complexes in tetrahydrofuran (THF) solution, measured at 77K, was analyzed. From the spectra, we have got not only hyperfine splitting of the ⁶³Cu and ⁶⁵Cu; but also very nice superhyperfine splitting arising from ¹⁴N and ¹⁵N nuclei. The g_x,g_y,g_z;A_x⁶⁵,A_y⁶⁵,A_z⁶⁵; A_⊥¹⁵,A_⊥¹⁵,A_⊥¹⁴,A_⊥¹⁴ etc. tensor parameters were determined rather reasonably. The bonding parameters were calculated by using measured spectral parameters, and its electronic structure and the bonding character of these complexes are discussed, and better satisfactory results were obtained.

Key words: Isotopes, Bis ((2)-Hydroxylphenyl Ketoxime), Copper (II) complexes, ESR