ランタノイド金属を含む低配位金属錯体から成る単一イオン磁石への計算化学的研究

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Our proposed research theme is modeling of spin-Hamiltonian parameters (zero-field splitting (D) and g-tensors) of transition metal (TM) and lanthanide (Ln) metal complexes using computational tools to understand their single-molecule magnetic (SMM) behavior. In this regard, nearly thirty model complexes such as two-, and three-coordinate divalent metal complexes of Fe, Co, and Ni, and Ln(III) complexes using bulky ligands have been optimized using Density Functional Theory (DFT) methods with B3LYP functional by GAUSSIAN 16 program. These optimization studies were very important to test the proposed theoretical protocols and, in some cases, lead to revision of our presented strategies earlier. Among the optimized molecules, I performed the ab initio CASSCF calculations on four molecules. For two Zn(II)-Ln(III) complexes, I have theoretically proven how a diamagnetic Zn(II) ion can help to enhance the energy barrier of lanthanide ions. For two Co(II) complexes, I have attempted to understand their origin of magnetic anisotropy in order to realize their SMM behavior. These results are discussed briefly here.(i) Zn(II)-Ln(III) complexes (Ln = Dy (1) and Tb (2)): Experimental measurement reveals SMM behavior for Dy complex and no SMM behavior for Tb complex.(ii) Co(II) (mononuclear (3) and dinuclear (4)) complexes: CASSCF calculations were performed to rationalize origin of magnetic anisotropy by computing g- and D-tensors for complexes 3 and 4 and to compute the magnetic exchange between the Co ions in 4, DFT calculations were performed.