NMR SPECTROSCOPIC AND COMPUTATIONAL INVESTIGATIONS OF SIGMA-INTERACTIONS IN CARBOCATIONS - THE BETA-SILYL EFFECT IN VINYL CATIONS

Authors
SIEHL HU
Citation
Hu. Siehl, NMR SPECTROSCOPIC AND COMPUTATIONAL INVESTIGATIONS OF SIGMA-INTERACTIONS IN CARBOCATIONS - THE BETA-SILYL EFFECT IN VINYL CATIONS, Pure and applied chemistry, 67(5), 1995, pp. 769-775
Citations number
13
Categorie Soggetti
Chemistry
Journal title
Pure and applied chemistry → ACNP
ISSN journal
00334545
Volume
67
Issue
5
Year of publication
1995
Pages
769 - 775
Database
ISI
SICI code
0033-4545(1995)67:5<769:NSACIO>2.0.ZU;2-U
Abstract
The para carbon chemical shift in 1-mesityl substituted vinyl cations and the torsional barrier for the methoxy group rotation in 1-p(anisyl )vinyl cations are used to evaluate the magnitude of the silyl effect. The hyperconjugative stabilization by beta-silicon groups and the acc ompanying geometrical distortions are studied experimentally and compu tationally in dienyl-cations and 1-cyclopropylvinyl cations. A geminal methyl substituent enhances the interaction of a beta-silyl group wit h the vacant p-orbital.