DFT and MM description of the structure and magnetic properties of manganese complexes with X-phenylcyanamido bridging ligand

摘要

Magnetic properties of the complexes [Mn(3-Clpcyd)(H2O)-(phen)2]~+, [{Mn(3-Fpcyd)(MeOH)(phen)}2 (μ-3-Fpcyd)2], [{Mn(3-Fpcyd)(EtOH)(phen)}2(μ-3-Fpcyd)2], [{Mn(3-Clpcyd)(MeOH)(phen)2(μ-3-Clpcyd)2], and [{Mn (4-Clpcyd)(EtOH)(phen)}2(μ-4-Clpcyd)2] (where Xpcyd = halogeno-phenylcyanamido; phen = 1,10-phenanthroline) have been explored by means of density functional theory (DFT). Exchange coupling constants were calculated from the energy differences between the high-spin and broken-symmetry states. Very good agreement between theoretical and experimental data was achieved. The g-tensor calculations were performed employing the coupled perturbed Kohn-Sham equations. Molecular mechanics calculations have been performed to elucidate structural features in the five complexes. Finally, the reliability of the molecular mechanics results was confirmed by comparing the magnetic couplings calculated on optimized structures with experimental data.