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本文报道的化合物为黑色准八面体状晶体,属斜方晶系,空间群为Pna2_1,晶胞参数为:a=17.815(1),b=16.629(2),c=12.003(1)A,z=4,ρ_(obs)=1.80g·cm~(-3),ρ_(calc)=1.804g·cm~(-3),晶体结构用重原子法解出,经全矩阵最小二乘方精修,对2584个 I≥3σ(I)的独立衍射的最终偏离因子R为 0.048.结果表明,晶体结构由四乙基胺阳离子和三核钼簇阴离子所组成.簇阴离子是单(μ_3—0)帽三核簇,Mo—Mo间距平均为2.60(2)A.在与μ_3—O原子相对的Mo_3。三角形面的另一方,每两个Mo原子之间各由一个C1原子桥联.这七个原子形成一种缺顶点的畸变类立方烷构型.另外,每个Mo原子还由其他三个原子补充配位成接近八面体构型.这些配位原子是两个乙酰基的氧原子和5个氯原子.乙酰基的两个氧原子分别与相邻两个Mo原子配位.簇阴离子接近于C_m对称性。
The compounds reported in this paper are black quasi- octahedral crystals belonging to the orthorhombic system with space group Pna2_1. The unit cell parameters are a = 17.815 (1), b = 16.629 (2), c = 12.003 (1) A, ρ_ (obs) = 1.80g · cm ~ (3), ρ calc = 1.804g · cm ~ (-3). The crystal structure was solved by heavy atom method and refined by full matrix least squares , And the final deviation factor R for the independent diffraction of 2584 I ≧ 3σ (I) is 0.048.The results show that the crystal structure is composed of tetraethylammonium cation and trinuclear molybdenum cluster anion.The cluster anion is single (μ_3-0) Cap triple-core clusters, the average Mo-Mo spacing is 2.60 (2) A. In the Mo_3 with the μ_3-O atoms. On the other side of the triangular plane, every two Mo atoms are bridged by one C1 atom, and these seven atoms form a kind of distorted quasi-cubic structure with no vertex. In addition, each Mo atom is also composed of three other atoms Complement the coordination octahedral configuration.These atoms are two acetyl oxygen atoms and five chlorine atoms.Oxygen two oxygen atoms respectively with two adjacent Mo atoms coordinate cluster anions close to C_m Symmetry.