Silicon Analogs of Unsaturated Hydrocarbons

The existing fundamental similarities in the chemistry of structurally related carbon and silicon compounds have been demonstrated. Stable silicon analogs of ethylene, silenes or silaethylenes R2C=SiR2 and disilenes R2Si=SiR2, as well as ethyne (acetylene) analogs, disilynes RSi≡SiR, have been considered. A number of unique branched (bulky) organic and organosilicon substituents have been described; the introduction of such substituents to double- or triple-bonded silicon atoms makes it possible to protect the latter from the action of atmospheric oxygen and moisture and prevent secondary dimerization (oligomerization) processes. Examples are given of steric protection for obtaining kinetically stable unsaturated silicon compounds which were characterized by IR, NMR, and UV-Vis spectroscopy and X-ray analysis.