钼簇合物反应性能的研究: {Mo3S4[S2P(OEt)2]4H2O}的加硫反应以及产物{Mo3(μ3-S)(μ-S2)3[S2P(OEt2]3I}的晶体结构

由贫硫化合物{Mo_3S_4S_2P(OEt)_2]_4·H_2O}通过加硫获得了富硫化合物{Mo_3S_7S_2P(OEt)_2]_3·I}(CH_8C_6H_5).化合物属三斜晶系,空间群PI,晶胞参数为a=10.350(1)A,b=13.931(4)A,c=16.369(3)A,α=103.69(2),β=86.62(1),γ=111.99(2)°,V=2183A~3;z=2,D_c=1.817g·cm~(-3).最终结构偏离因子R为0.042. 簇分子{Mo_3(μ_3-S)(μ-S_2)_3S_2P(OEt)_2]3·I}属{Mo_3(μ3一Y)(μ-S_2)_3S_2P(OEt)_2]_3·X}(Y=O,S;X=Cl,I)系列构型.{Mo_3}基本上是一个正三角形,Mo—Mo键长分别为2.721(1),2.724(1),2.725(1)A,Mo的配位多面体为七个硫原子组成的畸变五角双锥,有一个I原子联结着三个(S_2)~(2-)桥基的三个不与Mo共平面的S原子,I—S距离平均为3.169A,比相应的Van der Waals距离(～4.00A)明显地短,显示一定程度的成键作用,簇分子的这一构型是一种较为稳定的结构类型.

Studies on the reactivities of molybdenum clusters: The sulfur-addition reaction of {Mo3S4[S2P(OEt02]4.H2O} and the crystal structure of the product {Mo3(\m\3-S)(\m\-S2)3[S2P(OEt)2]3.I}

The S-deficient compound {Mo3S4S2P(OEt)2]3.H2O} was converted through the S addition reaction into S-rich compound {Mo3S7S2P(OEt)2]3.I}(CH3C6H5) (I). I forms crystals in space group P1 with Z = 2, a 10.350(1), b 13.931(4), c = 16.396(3) ? a 103.69(2), b 86.62(1), g 11.99(2)? d.(calcd.) = 1.817 g cm-3, R = 0.042. The formulation of I is of the general type {Mo3(m3-Z)(m-S2)3S2P(OEt)2]3.X} (Z = O, S; X = Cl, I). There exists an essentially equilateral triangle of Mo atoms with the Mo-Mo bond lengths being 2.721(1), 2.724(1), 2.725(1) ? resp. Moreover, each Mo atom is coordinated with 7 S atoms forming a distorted pentagonal bipyramid. On the top of 3 S atoms out of Mo plane there is an iodine atom connecting these S atoms with an average distance of 3.169 ? which is obviously shorter than the corresponding Van der Waals contact (~4.00 ?, showing a bonding interaction. The configuration of trinuclear Mo cluster is therefore stable.