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

我们提出的研究主题是利用计算工具对过渡金属（TM）和镧系金属（Ln）配合物的自旋哈密顿参数（零场分裂(D)和g张量）进行建模，以了解它们的单分子磁性（SMM）行为。在此基础上，利用密度泛函理论（DFT）方法，利用高斯16程序对近30种模型配合物进行了优化，包括Fe、Co、Ni的二坐标和三坐标二价金属配合物，以及使用大体积配体的Ln（III）配合物。这些优化研究对于测试提出的理论协议非常重要，并且在某些情况下，可以提前修改我们提出的策略。在优化的分子中，我对4个分子进行了从头算CASSCF计算。对于两个Zn(II)-Ln（III）配合物，我已经从理论上证明了抗磁性Zn（II）离子如何有助于增强镧系离子的能量垒。对于两种Co（II）配合物，我试图了解它们磁各向异性的起源，以实现它们的SMM行为。这里对这些结果作简要讨论。(i) Zn(II)-Ln（III）配合物(Ln = Dy(1)和Tb(2))：实验测量表明，Dy配合物具有SMM行为，而Tb配合物无SMM行为。（ii） Co(ii)(单核（3)和双核(4)）配合物：通过计算配合物3和4的g张量和d张量，进行CASSCF计算来合理化磁各向异性的起源，并进行DFT计算来计算4中Co离子之间的磁交换。

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.