Photochemistry of Matrix-Isolated Di-tert-butyldiazidosilane. Observation of Di-tert-butylsilylene and N,N'-Di-tert-butylsilanediimine

摘要

The major product from 254-nm irradiation of matrix-isolated di-tert-butyldiazidosilane (3) is di-tert-butylsilylene (4), a highly reactive ground-state singlet species with lambda max 480 nm, which undergoes a subsequent photochemical C-H insertion to give the stable 1-tert-butyl-2,2-dimethyl-1-silacyclopropane (5). The photochemical formation of 4 proceeds in at least two steps. A small amount (<5%) of a photochemical precursor to 4 is observed, with lambda max 300 nm and an IR band at 2150/cm, tentatively assigned as di-tert-butyldiazosilane (7). The irradiation of 3 also yields N,N'-di-tert-butylsilanediimine (6) as a minor (11%) product, with lambda max 240 and 385 nm. This process also involves at least two steps, and a very small yield of an intermediate (lamda max 725 nm) of an unknown structure was detected. Keywords: Silanes, Reprints, Imines. (MJM)