Theoretical investigation of EPR and molecular orbital coefficient parameters for [Cu(hsm)2(sac)2] complex

In this study, the molecular orbital coefficients and the spin Hamiltonian parameters of bis(histamine-saccharinate) copper(II) complex, [Cu(hsm)2(sac)2], are calculated theoretically. Two d–d transition spectra and four EPR parameters g ∥ , g ⊥ , A ∥ , A ⊥ for the Cu(II) complex are calculated by using crystal-field theory. The calculated values are in good agreement with the experimental values. The g and A parameters have indicated that the paramagnetic centre is axially symmetric. Having the relations of g ∥ > g ⊥ > g e and A ∥ > A ⊥ for Cu2+ ions, it can be concluded that Cu2+ ions are located in distorted octahedral sites (D4h) elongated along the z-axis and that the ground state of the paramagnetic electron is d x 2 - y 2 (2B1g state).