钼的原子簇化合物研究——一些两核和三核钼原子簇化合物的合成与晶体结构分析

本文总结了作者们研究一系列两核和三核钼原子簇化合物的结果。这些化合物是三核原子簇: (C_5H_7S_2)_3[Mo_3(μ_3-S)_2(μ_2-Cl)_3Cl_6] (Ⅰ); (C_5H_7S_2)_3[Mo_3(μ_3-S)(μ_2-S_2)_3Cl_7] (Ⅱ); Mo_3(μ_3-S)(μ_2-S_2)_3[S_2P(OEt)_2)_3Cl (Ⅲ); (Et_4N)_2[Mo_3(μ_3-O)(μ_2-Cl)_3(Oac)_2Cl_5] (Ⅳ); (C_5H_7S_2)[Mo_3(μ_3-O)(μ_2-Cl)_3(Oac)_3Cl_3] (Ⅴ); 和两核原子簇: (C_5H_7S_2)_3[Mo_2Cl_9] (Ⅵ); M0_2S_4[S_2P(OEt)_2]_2 (Ⅶ)。 本文的第一部分简要地介绍了这些化合物的合成方法。第二部分扼要地给出了这些化合物的晶体与分子结构。簇合物Ⅰ是离子型结构,簇阴离子是双(S)帽三核原子簇,每个Mo原子周围为八面体六配位,Mo—Mo间距为2.617。簇阴离子Ⅱ和簇分子Ⅲ均是单(S)帽三核簇,Mo原子周围为畸变五角双锥构型,Mo—Mo键长分别为2.751和2.725。簇阴离子Ⅳ和Ⅴ均是单(O)帽三核簇,Mo原子周围的配位为畸变八面体,Mo—Mo键长分别为2.597和2.577。化合物Ⅵ是三(μ_2—Cl)桥两核原子簇,其构型为两个共面八面体,Mo—Mo间距为2.707。化合物Ⅶ为双(S)桥两核原子簇,Mo原子周围为四角锥配位,Mo—Mo键长为2.828。 本文的第三部分用简化分子轨道方法分析了三种主要类型的三核钼原子簇中Mo_3体系的M—M键?

Research on Molybdenum Clusters——Synthesis and Crystal Structure Analysisof Some Binuclear and Trinuclear Molybdenum Cluster Compounds

This paper reports the research authors carried out on a series of trinu-clear molybdenum clusters and dinuclear ones as wellIn the first part of this paper a brief comment is given to the synthetic methods of these clusters. The second part describes their crystal and molecular structures. The structure of Cluster Ⅰ is ionic, in which the anion is a sulfido bicapped trinuclear cluster with an average distance between Mo atoms of 2.617A. Each Mo atom has an octahedral coordination. Cluster anion Ⅱ and cluster molecule Ⅲ are both sulfido monocapped trinuclear with mean bond lengths between Mo atoms of 2.751 and 2.725A respectively.The coordination of each Mo atom may be regarded as a distorted pentagonal bipyramid. Clusters Ⅳ and Ⅴ are oxo monocapped trinuclear with average Mo-Mo bond lengths of 2.597 and 2.577A respectively. Compound Ⅵ is a tris(μ2 - chloro)-bridged dinuclear cluster, having a configuration of two confacial octahedra with an Mo-Mp bond length of 2.707A. Compound Ⅶ is a bis (μ2 - sulfiddo) -bridged dinuclear cluster with an Mo-Mo bond length of 2.828A. The coordination of each Mo atom is a tetragonal pyramid. The third part analyzes the characteristics of the M-M bonds in the three main Mo3 systems of the trinuclear clusters. The bond orders obtained coincide satisfactorily with corresponding observed bond lengths.