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

Abstract

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(parallel to), g(perpendicular to), A(parallel to), A(perpendicular to) 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(parallel to) > g(perpendicular to) > g(e) and A(parallel to) > A(perpendicular to) for Cu2+ ions, it can be concluded that Cu2+ ions are located in distorted octahedral sites (D-4h) elongated along the z-axis and that the ground state of the paramagnetic electron is d(x2 - y2) (B-2(1g) state). (C) 2011 Elsevier B.V. All rights reserved.