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.