silyl azides resulted in the formation of triplet states even for those having two or three Si–N3 groups in a molecule. ESR spectra of the silylnitrenes exhibited a part of the fine structure at around 820 mT. All the silyl azides studied gave nearly identical D-values (ca. ) and much larger than those in phenylnitrenes. The results suggested that electron spins are localized in the nitrogen p-orbitals