Ungur Liviu, Pallitsch Katharina, AlOthman Zeid A, Al-Kahtani Abdullah A S, Arion Vladimir B, Chibotaru Liviu F
Department of Chemistry, National University of Singapore, Block S8 Level 3, 3 Science Drive 3, 117543, Singapore.
University of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria.
Dalton Trans. 2021 Sep 21;50(36):12537-12546. doi: 10.1039/d1dt01558c.
The magnetism of a recently synthesized -[OsCl(κN-Hind)] complex (5d-system), where Hind = 2-indazole, was studied experimentally and theoretically. Relativistic CASSCF/CASPT2 calculations for this and model [OsCl] complexes were employed to understand the nature of the low-lying multiplets. It is found that despite strong metal-ligand covalency they are basically characterized by the total angular pseudo-momentum originating from the spin-orbit coupling of the ground-state spin = 1 with the orbital pseudo-momentum = 1 of the Os ion. The strong spin-orbit interaction also preserves the dominant = 0 character of the non-magnetic ground state in the -[OsCl(κN-Hind)] complex despite significant deviation of the ligand environment of Os from octahedral symmetry. At the same time the spin-orbit admixture of all multiplets arising from the t strong-field electronic configuration is indispensable for the correct description of magnetic properties of Os complexes. Moreover, based on calculations, we argue that the charge-transfer states play an important role in the magnetism of the present and probably other 5d complexes, a situation never encountered for 3d and 4f compounds.
对最近合成的-[OsCl(κN-Hind)]配合物（5d体系，其中Hind = 2-吲唑）的磁性进行了实验和理论研究。对该配合物及模型[OsCl]配合物采用相对论CASSCF/CASPT2计算来理解低激发多重态的性质。结果发现，尽管金属-配体共价性很强，但它们基本上由源自基态自旋S = 1与Os离子轨道赝动量L = 1的自旋-轨道耦合的总角赝动量J来表征。尽管Os的配体环境与八面体对称性有显著偏差，但强自旋-轨道相互作用仍保持了-[OsCl(κN-Hind)]配合物中非磁性基态的主要J = 0特征。同时，由t强场电子构型产生的所有多重态的自旋-轨道混合对于正确描述Os配合物的磁性是不可或缺的。此外，基于计算，我们认为电荷转移态在当前以及可能其他5d配合物的磁性中起重要作用，这是3d和4f化合物从未遇到过的情况。
