Photolysis of organopolysilanes. The synthesis and reactions of stable silacyclopropenes

Abstract Two stable silacyclopropenes, 1,1-dimesityl-2,3-bis(trimethylsilyl)-1-silacyclopropene and 1,1-dimesityl-2-phenyl-3-trimethylsilyl-1-silacyclopropene, have been prepared by photolysis of 1,1-dimesityl-1-trimethylsilylethynyltrimethyldisilane and 1,1-dimesityl-1-phenylethynyldisilane, respectively. It has been found that these silacyclopropenes are not affected by atmospheric oxygen, moisture and alcohols at room temperature. 1-Mesityl-1-methyl-2-phenyl-3-trimethylsilyl-1-silacyclopropene prepared by the photolyisis of 1-mesityl-1-phenylethynyltetramethyldisilane is rather stable toward atmospheric oxygen, but reacts readily with methanol in benzene to give a ring-opening methoxysilane. Photochemical and thermal behavior of these silacyclopropenes has been investigated.