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

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 A) and planar bond length variation ΔR (≈0.015 A) related to an ideal octahedron due to the Jahn–Teller effect. The larger experimental axial anisotropy Δg (= (gx + gy)/2 − gz) of Cu(en)3SO4 than Cu(en)3Cu(CN)3 is mainly ascribed to the larger ΔZ (≈0.053 A) in the former. The calculated g factors for both systems show reasonable agreement with experiment by including the charge transfer (CT) contributions to gz, which have the same sign and much larger magnitude compared to the conventional crystal-field ones and should be included.