Yan Xiuli, Meng Lingpeng, Sun Zheng, Li Xiaoyan
College of Chemistry and Material Science, Hebei Normal University, Road East of 2nd Ring South, Shijiazhuang, 050024, China.
Key Laboratory of Inorganic Nano-Materials of Hebei Province, Shijiazhuang, 050024, China.
J Mol Model. 2016 Feb;22(2):48. doi: 10.1007/s00894-016-2912-5. Epub 2016 Jan 29.
The nature of M-M bonding and aromaticity of [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh) was investigated using atoms in molecules (AIM) theory, electron localization function (ELF), natural bond orbital (NBO) and molecular orbital analysis. These analyses led to the following main conclusions: in [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh), the Nb-Nb, Ru-Ru, and Rh-Rh bonds belong to "metallic" bonds, whereas Mo-Mo and Tc-Tc drifted toward the "dative" side; all these bonds are partially covalent in character. The Nb-Nb, Mo-Mo, and Tc-Tc bonds are stronger than Ru-Ru and Rh-Rh bonds. The M-M bonds in [M2(NHCHNH)3]2(μ-S)2 are stronger than those in [M2(NHCHNH)3]2(μ-O)2 for M = Nb, Mo, Tc, and Ru. The NICS(1)ZZ values show that all of the studied molecules, except [Ru2(NHCHNH)3]2(μ-O)2, are aromaticity molecules. O-bridged compounds have more aromaticity than S-bridged compounds. Graphical Abstract Left Molecular graph, and right electron localization function (ELF) isosurface of [M2(NHCHNH)3]2(μ-E)2(E = O, S; M = Nb, Mo, Tc, Ru, Rh).
利用分子中的原子（AIM）理论、电子定域函数（ELF）、自然键轨道（NBO）和分子轨道分析，研究了[M2(NHCHNH)3]2(μ-E)2（E = O，S；M = Nb，Mo，Tc，Ru，Rh）的M-M键性质和芳香性。这些分析得出以下主要结论：在[M2(NHCHNH)3]2(μ-E)2（E = O，S；M = Nb，Mo，Tc，Ru，Rh）中，Nb-Nb、Ru-Ru和Rh-Rh键属于“金属”键，而Mo-Mo和Tc-Tc键则向“配位”键一侧偏移；所有这些键都具有部分共价性质。Nb-Nb、Mo-Mo和Tc-Tc键比Ru-Ru和Rh-Rh键更强。对于M = Nb、Mo、Tc和Ru，[M2(NHCHNH)3]2(μ-S)2中的M-M键比[M2(NHCHNH)3]2(μ-O)2中的M-M键更强。NICS(1)ZZ值表明，除[Ru2(NHCHNH)3]2(μ-O)2外，所有研究的分子都是芳香性分子。O桥连化合物比S桥连化合物具有更多的芳香性。图形摘要 左为[M2(NHCHNH)3]2(μ-E)2（E = O，S；M = Nb，Mo，Tc，Ru，Rh）的分子图，右为电子定域函数（ELF）等值面。
