Switching of the exchange interaction character in the binuclear copper(II) complexes based on the hetaryl derivatives of 1,3-diaminopropanol-2

Resumo

The binuclear copper(II) complex with bis-azomethine, viz., the product of condensation of 1,3-diaminopropanol-2 with 4-hydroxy-3-formylcoumarin (H₃L), of the composition [Cu₂L(μ₂-CH₃COO)] (I) is synthesized and studied. Complex I is characterized by the exchange interaction of the antiferromagnetic type (2J =–112 cm^–1), which is switched to the ferromagnetic one (2J = +106 cm–1) after the recrystallization of the complex from dimethyl sulfoxide (DMSO) to form solvate [Cu₂L(μ₂-CH₃COO)(μ₂-DMSO)] · 0.5DMSO (II). The structure of solvate II is studied by X-ray diffraction analysis (CIF file CCDC no. 982198). The difference in the exchange character is explained by the stabilization by the μ₂-coordinated DMSO molecule of a distorted (roof-shaped type) conformation of the polydentate ligand and the complex as a whole, unlike the symmetric conformation characteristic of the nonsolvated complex. The data obtained are compared with those on similar compounds synthesized earlier and with the quantum chemical modeling results for the exchange interaction in the framework of the DFT-BS approximation.