Magnetic Properties and Crystal Structure of a Cu^IIGd^III Heterodinuclear Schiff Base Complex

Abstract

The crystal structure and the magnetic properties of a heterodinuclear complex, [LCu(Me₂CO)Gd(NO₃)₃]₂ (L=N,N’-bis(2-hydroxy-3-methoxybenzylidene)-1,3-diaminopropane) are reported: [(C₁₉H₂₀N₂O₄)Cu(C₃H₆O)Gd(NO₃)₃]₂, triclinic, space group P1, with a = 12.118.3(9), b = 13.562(3), c = 9.391(3) Å , α = 93.03(3), β = 107.65(2), γ = 73.07(2)°, V = 1406.0(7) ų, Z = 1. The crystal structure consists of two independent binuclear Cu^IIGd^III complexes and two non-coordinating acetone molecules in the asymmetric unit. The central region of the complexs is occupied by Cu^II and Gd^III ions which are bridged by two phenolato oxygen atoms of the ligand. The Cu^II ion is in a square-planar geometry and coordinated by four donor atoms of the ligand (N₂O₂). The Gd^III ion is deca-coordinated. In addition to the two phenolate oxygen atoms, its coordination sphere contains two oxygen atoms of the OMe side arms of L and six oxygen atoms from the three bidentate nitrate ions. The average Cu···Gd separation is 3.375(2) Å . The χT versus T plots, χ being the molar magnetic susceptibility per Cu^IIGd^III unit and T the temperature, has been measured in the 4 - 347 K range. The values of the intrachain interaction parameters have been deduced from the magnetic data: J = 7.4 cm⁻¹, g_Cu = 2.12, g_Gd = 2.06. This indicates a weak ferromagnetic spin exchange interaction between Cu^II and Gd^III ions. The nature of the magnetic super-exchange interaction of the title compound is compared with similar Cu^IIGd^III heterodinuclear complexes.