Synthesis of Novel Silicon-containing Multiple-bond Compounds by Taking Advantage of Steric Protection and Investigation of Their Structures and Reactivities

利用空间保护合成新型含硅多重键化合物及其结构和反应性研究

基本信息

批准号：
07454193
负责人：
TOKITOH Norihiro
金额：
$ 5.12万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

1.The first stable silanethione Tbt(Tip)Si=S(1 : Tbt=2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, Tip=2,4,6-triisopropylphenyl)was successfully synthesized by the desulfurization of the corres-ponding tetrathiasilolane, Tbt(Tip)SiS_4, with triphenylphoshine in hexane. Silanethione 1 was isolated as stable yellow crystals and it showed a characteristic downfield shifted signal at+166.6ppm(in C_6D_6)in the ^<29>Si NMR spectra suggesting the sp^2 character of the central silicon. The X-ray crystallographic structural analysis revealed that the Si-S bond length of 1 is ca. 9% shorter than that of the typical Si-Si single bond compounds and the silathiocarbonyl unit of 1 has a completely trigonal planar geometry as in the case of ketones. Silinethione 1 was found to have an enough space around the central siliconatom to react with small molecules, though the bulky substituents on Si atom of 1 effectively prevent its self-dimerization.2.The synthesis of a stable silaketeneimine, Tbt(Mes)Si=C … More =NAr, was also examined by the reaction of a sterically protected silylene Tbt(Mes)Si : (Mes=mesityl), which was found to be readily available on the thermolysis of the corresponding disilenes Tbt(Mes)Si=Si(Mes)Tbt, with several kinds of isocyanides bearing bulky aromatic substituents. The spectroscopic investigation on the resulting blue or greenish blue pastes revealed that the silylene adducts of isocyanides here obtianed were not the cumulative double-bond species but the novel silylene-isocyanide complexes. This is the first examples of isolated silyene-Lewis base complexes.3.The thermal reaction of an overcrowded silascylopropane derivative in the presence of elemental selenium resulted in the formation of silaneselone Tbt(Dip)Si=Se(Dip=2,6-diisopropyl-phenyl)stable in solution.As an extension of this research project, the double-bond species between germanium and heavier chalcogen atoms kinetically stablilized by taking advantage of the Tbt group, i.e.germanethiones, germaneselones, and germanetellones Tbt(R)Ge=X[X=S,Se, Te ; R=Tip or CH(SiMe_3)_2], were all synthesized and isolated as stable crystalline compounds. These results have been partially published as papers listed in the references. Less

1.通过脱硫法成功合成第一个稳定的硅烷硫酮Tbt(Tip)Si=S(1 : Tbt=2,4,6-三[双(三甲基硅基)甲基]苯基,Tip=2,4,6-三异丙基苯基)相应的四硫硅烷Tbt(Tip)SiS_4 与三苯基膦在己烷中的反应。硅烷硫酮1被分离为稳定的黄色晶体，并且其在^ 29 Si NMR谱中在+166.6ppm(在C_6D_6中)处显示出特征性低场位移信号，表明中心硅的sp^2特征。分析表明1的Si-S键长比典型的Si-Si单键化合物短约9%，并且1的硅硫羰基单元具有完全的结构。与酮的情况一样，硅硫酮 1 具有三角形平面几何结构，尽管 1 的硅原子上的大取代基有效地阻止了其自二聚化，但其中心硅原子周围有足够的空间可以与小分子反应。稳定的硅烯亚胺，Tbt(Mes)Si=C … More =NAr，也通过空间保护的亚硅基 Tbt(Mes)Si 的反应进行了检查： (Mes=异丙叉基)，发现很容易通过热解相应的二硅烯 Tbt(Mes)Si=Si(Mes)Tbt，与几种带有大量芳香族取代基的异氰化物进行光谱研究。绿蓝色糊状物表明，此处获得的异氰化物的亚硅基加合物不是累积双键物质，而是新型亚硅基-异氰化物这是分离的硅烯-路易斯碱配合物的第一个例子。3.在元素硒存在下，过度拥挤的硅环丙烷衍生物的热反应导致形成硅烷酮Tbt(Dip)Si=Se(Dip=2,6)。 -二异丙基苯基）在溶液中稳定。作为该研究项目的延伸，锗和较重原子之间的双键物质利用 Tbt 基团实现动力学稳定的硫族原子，即germanethiones、germaneselones 和 germanetellones Tbt(R)Ge=X[X=S,Se, Te ；R=Tip 或 CH(SiMe_3)_2] 均已合成并这些结果已部分作为参考文献中列出的论文发表。