Jg. Radziszewski et al., TWISTED SI=N BONDS - MATRIX-ISOLATION OF BRIDGEHEAD SILANIMINES, Journal of the American Chemical Society, 115(18), 1993, pp. 8401-8408
We report the IR and UV-vis spectra of three bridgehead silanimines, 1
-sila-2-azabicyclo[3.2.2]non-1(2)-ene, 1-sila-2-azabicyclo[3.2.1]oct-1
(2)-ene, and 1-sila-2-azabicyclo[2.2.2]oct-1(2)-ene, prepared in matri
x isolation by UV irradiation of bridgehead silyl azide precursors and
characterized by chemical trapping with trimethoxymethylsilane with a
nd without prior selective photodestruction with light of suitable wav
elengths. The IR spectra of the N-14 and N-15 species and the n --> pi
transition in their UV-vis spectra arc in good agreement with ab ini
tio computations. It is concluded that pi bonding plays a crucial role
in determining the properties of silanimines.