Syntheses, Structures and Magnetic Properties of Novel Oxamido‐Bridged Tetranuclear Complexes [Cu3M] (M = Cu, Mn)

Abstract

AbstractThree oxamido‐bridged tetranuclear complexes with the formulae [(LCu)Cu(LCuSCN)2]·H2O (1), [(LCu)Mn(LCuSCN)2]·1.38CH3OH (2) and {(LCu)Mn[LCuN(CN)2]2}·0.75DMF·0.25H2O (3) (where H2L = 2,3‐dioxo‐5,6:15,16‐dibenzo‐1,4,8,13‐tetraazacylotetradeca‐7,13‐diene) have been prepared and characterised. Their structures were deduced using X‐ray crystallography. All three complexes crystallise in the triclinic system, space group P$\bar 1$ . The three copper ions of the complex ligands and the central metal ions (Cu, Mn) remain in the plane and form a scalene triangle. Three copper ions occupy the vertexes and the M(Cu, Mn) ions are located at the centre. Magnetic susceptibility measurements in the 5−300 K temperature range have been carried out for this series of complexes. The experimental data have been fitted according to the Heisenberg Hamiltonian and led to J values equal to −61.80 cm−1, −14.54 cm−1 and −12.10 cm−1 for complex 1, 2 and 3, respectively. Their interaction parameters have been compared with each other. The deviation of the copper ions from the oxamide‐bridge plane results in the J value of complex 1 being different from those of other oxamide‐bridged copper complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)