簇合物配基置换反应的研究——Mo3S4(μ-dtp)(η2-dtp)2(η1-dtp)(bpy)的合成与晶体结构

应用X-射线单晶衍射方法, 测定2,2-联吡啶(bpy)和簇合物MO_3S_4(μ-dtp)(dtp)_3(H_2O)(Ⅰ)反应产物褰峁埂ａ果? 产物为Mo_3S_4(μ-dtp)(η~2-dtp)_2(η~1-dtp)(bpy)(Ⅱ), 即联吡啶置换了簇合物(Ⅰ)中的端基(H_2O)和端基(dtp)中的一啮。簇合物(Ⅱ)晶体属三斜晶系。晶胞参数为:a=1.3638(3); b=1.3983(3); c=1.4699(2) nm, a=95.57(2)°, β=91.87(2)°, γ=117.40(2)°; V=2.4676 nm; Z=2; D_C=1.767 g·cm~(-3)。晶体的空间群为P1。最终偏离因子R=0.069, R_w=0.076。本文结合过去对簇合物(Ⅰ)进行的四种不同类型的置换反应的研究, 进行了必要的讨论。并指出本文中的反应是松散本位促进的配基置换反应。

RESEARCH ON SUBSTITUTION REACTION OF LIGANDS IN Mo3S4(dtp)4(H2O)——SYNTHESIS AND CRYSTAL OF Mo3S4(μ-dtp)(η2-dtp)2(η1-dtp)(bpy)

From the reaction of Mo_2S_4(μ-dtp)(dtp)_3(H_2O) (I) (dtp = diethyldithiophosphanato) with 2,2'-bipyridine, the product Mo_3S_4(μ-dtp)(η~2-dtp)_2(η~1-dtp)(bpy)(Ⅱ) has been isolated, and characterized by X-ray crystallography. Crystal: (Ⅱ) belongs to triclinic system in space group Pi with crystallographic parameters as following., a=1.3638(3), b=1.3983(3), c=1.4699(2) nm, α=95.57°, β=91.87°, γ=117.40°; V=2.467(2) nm, Z=2, Dc=1.767 g.cm~(-3), final R=0.069, R_w= 0.076. The results of the structure determination show that the coordinated H_2O ligand and one of sulphur atoms of dtp on the Mo(3) atom of cluser(Ⅰ) have been substituted by 2,2′-bipyridine ligand. It has been pointed out that the ligand substitution reaction reported here is closely correlated with the existence of loosely-coordinated site in cluster (Ⅰ). In addition, the other types of substitution reactions of ligands are also discussed.