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本文所研究的晶体属单斜晶系,空间群为P2_1/C。晶体结构由重原子法及差值Fourier合成解出,最小二乘方修正,对3261个I≥3σ(I)独立衍射的最终R因子为0.040。晶体结构由两套四乙基胺阳离子及三核钼原子簇阴离子组成。在簇阴离子中,三个钼原子呈等腰三角形分布。Mo—Mo间距为2.601(1),2.608(1)及2.642(1),表明金属原子间较强的成键作用。一个μ_3-O原子及一个μ_3-Cl原子分别处在三角形的上下与钼原子形成三角双锥簇核。每两个钼原子之间还各由一个与钼三角形共面的μ_2-Cl原子桥联。此外,每个钼原子还有两个端基Cl原子作为补充配位,从而使每个钼原子的配位成为稍为畸变的八面体。
The crystal studied in this paper is monoclinic with space group P2_1 / C. The crystal structure was solved by heavy atom method and difference Fourier synthesis. The least square correction was performed, and the final R factor of 3261 independent diffraction with I≥3σ (I) was 0.040. The crystal structure consists of two sets of tetraethylammonium cations and tri-nuclear molybdenum cluster anions. In cluster anions, the three molybdenum atoms are distributed in an isosceles triangle. The Mo-Mo spacing is 2.601 (1), 2.608 (1) and 2.642 (1), indicating a strong bond between metal atoms. A μ_3-O atom and a μ_3-Cl atom respectively form a triangular double-cone cluster nucleus at the upper and lower sides of the triangle with the molybdenum atom. Each two molybdenum atoms also by a molybdenum triangular coplanar μ_2-Cl atoms bridge. In addition, there are two terminal Cl atoms per molybdenum atom as complementary ligands, so that the coordination of each molybdenum atom becomes a slightly distorted octahedron.