SYNTHESIS OF FUNCTIONAL UNSATURATED SILICON COMPOUNDS

通过cis-NaS-HC=CH-SNa与相应的二氯硅烷反应，合成了几种1，3-二硫杂-2-硅杂环戊二烯-4-烯（二硫杂环戊二烯）衍生物。在CH_2Cl_2溶液中，该化合物与四氰基乙烯形成电荷转移络合物。紫外-可见吸收光谱表明，2，2-二（三甲基硅基）二硫杂环戊烯的电离势小于2，2-二甲基二硫杂环戊烯的电离势。这是由于σ（SiR）-π相互作用导致了较高的HOMO能级.从头计算结果支持了实验结果，首次分离到的稳定的4-硅三富烯衍生物1，2-二叔丁基-4，4-双（叔丁基二甲基硅基）-4-硅三富烯与二叔丁基环丙烯酮在70℃反应，得到了1-硅双环[3.2.0]庚三烯的淡黄色晶体（熔点122℃）。通过2-芳基-2-锂-1，3-二噻烷与相应的氯代硅烷反应，合成了一系列2-硅烷基和2-二硅烷基取代的2-芳基-1，3-二噻烷衍生物。2-苯基-2-（五甲基二硅烷基）-1，3-二噻烷的光解导致中间体1，1-二甲基-2-苯基-2-（三甲基硅烷基）-2-硅乙烯的形成。

Several 1,3-dithia-2-silacyclopent-4-ene (dithia-silole) derivatives were prepared by the reactions of cis-NaS-HC=CH-SNa with the corresponding dichlorosilanes. The compounds formed charge-transfer (CT) complexes with tetracyanoethylene in CH_2Cl_2. The UV-Vis spectra of the CT complexes indicated that the ionization potential of 2,2-bis (trimethylsilyl) dithiasilole was smaller than that of 2,2-dimethyldithiasilole. The results were explained by the σ(SiR)-πinteractions resulting in a higher HOMO level. Ab initio MO calculations supported the experimental results.The reaction of 1,2-di-t-butyl-4,4-bis (t-butyldimethylsilyl)-4-silatriafulvene, which we have isolated as the first stable 4-silatriafulvene derivative, with di-t-butylcyclopropenone at 70℃ gave 1-silabicyclo [3.2.0] heptatriene unusually as pale yellow crystals (mp 122℃) in quantitative yield. The highly strained structure of the product was determined by X-ray crystallography.A series of 2-silyl- and 2-disilanyl-substituted 2-aryl-1,3-dithiane derivatives were prepared by the reactions of 2-aryl-2-lithio-1,3-dithianes with the corresponding chlorosilanes. Photolysis of 2-phenyl-2-(pentamethyldisilanyl)-1,3-dithiane resulted in the intermediary formation of 1,1-dimethyl-2-phenyl-2-(trimethylsilyl)-2-silaethene.