NMR of terminal oxygen. Part 11. 17O NMR spectra of disilyl ketone and related compounds: a case of strong deshielding by electronic excitation energy

Abstract

The important deshielding effect on the 17O signal of the disilyl ketone 1(Δδ ca. 400 ppm, compared with normal ketones such as 3) and of the monosilylketones 2, is proportional to the λ values of the UV–VIS absorption spectra; in agreement with the r-term of the Karplus–Pople eqn. (1), it is four times larger than the analogous effect on the 13C signals of the carbonyl carbon.