Zheng Hong, Dang Haiping, Zhao Yaoxiao, Gu Yong-Xin, Li Mengyang, Li Qiao-Zhi, Zhao Xiang
Institute for Chemical Physics & Department of Chemistry, School of Science, State Key Laboratory of Electrical Insulation and Power Equipment, Center of Nanomaterials for Renewable Energy, and MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi'an Jiaotong University, Xi'an 710049, China.
Inorg Chem. 2020 Jul 20;59(14):10113-10122. doi: 10.1021/acs.inorgchem.0c01241. Epub 2020 Jul 1.
Recent experimental works recovered multiformity of lutetium-involved dimetallofullerenes. On the basis of density functional theory (DFT) combined with statistical thermodynamic analyses, the relative stabilities of LuC dimetallofullerene were clarified. Besides the experimentally acknowledged Lu@(51591)-C and Lu@(51575)-C, another four isomers metallofullerenes, Lu@(51580)-C, LuC@(39715)-C, LuC@(39717)-C, and LuC@(39718)-C, are first proposed as thermodynamically stable structures. Interestingly, the geometric relationships among the pristine cages of stable LuC isomers through Stone-Wales transformation or C lose/insertion reveal important clues of the fullerene formation mechanism. The ionic interaction in the stable LuC isomers is revealed, and their valence states are Lu@C or (LuC)@C. In the Lu@C isomers, the results of frontier molecular orbital and natural bond orbital analyses suggest that a Lu-Lu single bond is formed, which is mainly composed of the 6s and 6p orbitals of the Lu atoms. Further analyses of the M@C (M = Sc, Y, La, and Yb) structures disclose the importance of the electron configuration of metal element toward the formation of a single metal-metal bond in C. Moreover, the covalent interaction between the Lu moiety and the C cages is disclosed, which is a supplement to the ionic model.
近期的实验工作揭示了含镥双金属富勒烯的多样性。基于密度泛函理论（DFT）并结合统计热力学分析，阐明了LuC双金属富勒烯的相对稳定性。除了实验上已确认的Lu@(51591)-C和Lu@(51575)-C之外，首次提出另外四种异构体金属富勒烯，即Lu@(51580)-C、LuC@(39715)-C、LuC@(39717)-C和LuC@(39718)-C，为热力学稳定结构。有趣的是，通过斯通-威尔士变换或C原子的丢失/插入，稳定的LuC异构体的原始笼之间的几何关系揭示了富勒烯形成机制的重要线索。揭示了稳定的LuC异构体中的离子相互作用，其价态为Lu@C或(LuC)@C。在Lu@C异构体中，前线分子轨道和自然键轨道分析结果表明形成了Lu-Lu单键，该单键主要由Lu原子的6s和6p轨道组成。对M@C（M = Sc、Y、La和Yb）结构的进一步分析揭示了金属元素的电子构型对在C中形成单个金属-金属键的重要性。此外，还揭示了Lu部分与C笼之间的共价相互作用，这是对离子模型的补充。
