Solvent effects on the photochemical behavior of 1-(n-pyridyl)-2-(pentamethyldisilanyl)ethynes (n=2,3, or 4), aza analogs of 1-phenyl-2-(pentamethyldisilanyl)ethyne

Photolysis of 1-(n-pyridyl)-2-(pentamethyldisilanyl)ethynes (n=2,3, or 4) 1, 9, or 20, respectively, aza analogs of 1-phenyl-2-(pentamethyldisilanyl)ethyne, was performed in both non-polar and polar solvents. In benzene, they provide silacyclopropene and 1-sila-1,2-propadiene intermediates but afford only silacyclopropene intermediate in methanol.