An ESR study on structures of a series of silylnitrenes

Structures of a series of silylnitrenes formed from silyl azides were inves tigated by means of ESR. gamma -Irradiation and photo-illumination of all t he silyl azides resulted in the formation of triplet states even for those having two or three Si-N-3 groups in a molecule. ESR spectra of the silylni trenes exhibited a part of the fine structure at around 820 mT. All the sil yl azides studied gave nearly identical D-values (ca. 1.5 cm(-1)) and much larger than those in phenylnitrenes. The results suggested that electron sp ins are localized in the nitrogen p-orbitals to a large extent and was inte rpreted in terms of a mono-silane linkage of nitrene, -Si-N:, i.e., interru pting spin delocalization. (C) 2001 Elsevier Science B.V. All rights reserv ed.