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Cyclic oxonium salts: 13C magnetic resonance spectroscopy. The correlation of chemical shifts with the calculated charge density

✍ Scribed by J. P. Bégué; D. Bonnet-Delpon

Publisher
John Wiley and Sons
Year
1980
Tongue
English
Weight
659 KB
Volume
14
Category
Article
ISSN
0749-1581

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✦ Synopsis

Abstract

The ^13^C chemical shifts of several bicyclic and monocyclic oxonium salts are reported and, in the case of 5‐membered ring unsaturated oxonium salts, compared with ab initio and CNDO calculated charges. A prime dependence of the ^13^C shielding on the π charge delocalization effects induced by the Y group is established for the Y‐substituted C‐α carbon; a good correlation of δC‐α vs q^π^ is obtained, using π bond‐order terms. However, contradictory information arises from NMR and theoretical calculations for the C‐ω carbon, which is distant from the Y group. The results are discussed.

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