Elucidation of the magnetism of [Co(2)PdCl(2)(dpa)(4)]: origin of a large temperature domain of TIP behavior.
The recently synthesized heterotrimetallic complex [Co(2)PdCl(2)(dpa)(4)] shows an unusual temperature-independent paramagnetism (TIP), extending over the whole experimental temperature range (0-300 K; Rohmer et al. Angew. Chem., Int. Ed. 2007, 46, 3533). We explain this behavior from a microscopic approach, using ligand-field theory and Anderson's kinetic exchange theory, treating the nonmagnetic Pd(II) as a ligand. The orbital degeneracy of the Co(II) ions is taken into account in the construction of the model Hamiltonian. The extension of the TIP behavior, compared to that of mononuclear Co(II) compounds, over the whole temperature domain, is explained by the quenching of magnetic moments in thermally populated levels by a strong antiferromagnetic exchange interaction.
Van den Heuvel
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Division of Quantum Chemistry and Physical Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium. willem.vandenheuvel@chem.kuleuven.be
Chibotaru
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