Investigations of g Factors and Local Structures for Cu(en)\(_{3}^{{2 + }}\)Groups in Cu(en)3SO4 and Cu(en)3Cu(CN)3 Polycrystalline Powders

Abstract

From the perturbation formulas for g factors for an orthorhombically compressed octahedral 3d⁹ group, g factors, and local structures for the [Cu(en)₃]²⁺ groups in Cu(en)₃SO₄ and Cu(en)₃Cu(CN)₃ powders are theoretically investigated. The local structure of Cu²⁺ in Cu(en)₃Cu(CN)₃ is evaluated by analyzing the experimental g factors and found to exhibit moderate axial compression ΔZ (≈0.018 Å) and planar bond length variation ΔR (≈0.015 Å) related to an ideal octahedron due to the Jahn–Teller effect. The larger experimental axial anisotropy Δg (= (g_x + g_y)/2 − g_z) of Cu(en)₃SO₄ than Cu(en)₃Cu(CN)₃ is mainly ascribed to the larger ΔZ (≈0.053 Å) in the former. The calculated g factors for both systems show reasonable agreement with experiment by including the charge transfer (CT) contributions to g_z, which have the same sign and much larger magnitude compared to the conventional crystal-field ones and should be included.