论文部分内容阅读
本文所研究的晶体系金黄色菱片状。空间群为单斜晶系的P2_1/n。晶体结构主要用重原子法解出,经全矩阵最小二乘方精修,对4387个I≥2σ(I)的独立衍射的最终R因子值为0.047。结果表明,晶体结构由单氧帽中性三核钼簇合物分子所组成。Mo—Mo间距平均为2.626(4),Mo—O间距平均为2.036(2)。每两个钼原子之间还有一个S_2~(2-)基团作二重桥,其中一个S原子基本上处在三个钼原子构成的平面上,另一个处在平面外与μ_3-O原子相对的另一边。此外,每个钼原子还由一个[S_2P(OEt)_2]~-基团中的两个S原子补充配位,使得钼原子的局部配位氛接近于五角双锥。另外,在这三个平面外的S原子的顶部还有一个碘原子对这三个S原子起三重桥联作用,使得簇廓中的部份原子形成扭曲的类立方烷结构。
The crystal studied in this paper is golden yellow diamond flake. The space group is monoclinic P2_1 / n. The crystal structure was solved mainly by heavy atom method. The final R factor of 4387 independent diffraction with I≥2σ (I) was 0.047 after the whole matrix least squares refinement. The results show that the crystal structure consists of mono-oxygen cap trinuclear molybdenum cluster molecules. The average Mo-Mo spacing was 2.626 (4), and the average Mo-O spacing was 2.036 (2). There is also a S_2 ~ (2-) group as a double bridge between every two molybdenum atoms, one of which is basically on the plane of three molybdenum atoms and the other is out of plane with μ_3-O The opposite side of the atom. In addition, each molybdenum atom is further coordinated by two S atoms in a [S 2 P (OEt) _2] ~ - group, such that the local coordination atmosphere of molybdenum atoms is close to the pentagonal bipyramid. In addition, there is an iodine atom at the top of these three out-of-plane S atoms that makes a triple-bridging effect on these three S atoms, resulting in the formation of a twisted quasi-cubic structure of some of the atoms in the cluster.