RESEARCH ON TRINUCLEAR MOLYBDENUM CLUSTER COMPOUNDS——CRYSTAL AND MOLECULAR STRUCTURE OF （C5H7S2）3Mo3（μ3-S）（μ2-S2）3Cl7

摘要

＜正＞ The space group of the title crystal is Pnam. The unit cell parameters are: a=17.226（4）, b=14.306（7）, c=15.074（4）; z=4, Dobs=2.03g·cm-3, Dcalc=2.063g·cm-3. The crystal structure was solved by the heavy atom method and refined by the full-matrix least-squares until the final conventional discrepancy factor was reduced to 0.068. The results of the investigation show that the crystal consists of trinuclear Mo cluster anions [Mo3（μ3-S）（μ2-S2）3Cl7]3- together with planar （C5H7S2）+ monocations, surrounding the cluster anions. In the cluster anion three Mo atoms, forming a nearly equilateral triangle （2.755（1）, 2.755（1）, 2.743（1））, are bound by a μ3-S bridging atom, while each pair of Mo atoms is bridged further by a μ2-S2 ligand. Besides, each Mo atom is coordinated to two terminal Cl atoms, so that the coordination sphere of each Mo atom approaches closely a pentagonal bipyramid. In addition, a single Gl atom, not at all involved in the coordination spheres of the three Mo atom