Acidity inversions of alpha-NO2 and alpha-SO2CF3 activated carbon acids as a result of contrasting solvent effects on transfer from water to dimethyl sulfoxide solutions | Health & Environmental Research Online (HERO)

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Citation
Tags

HERO ID

1644382

Reference Type

Journal Article

Title

Acidity inversions of alpha-NO2 and alpha-SO2CF3 activated carbon acids as a result of contrasting solvent effects on transfer from water to dimethyl sulfoxide solutions

Author(s)

Goumont, R; Magnier, E; Kizilian, E; Terrier, F

Year

2003

Is Peer Reviewed?

Yes

Journal

Journal of Organic Chemistry
ISSN: 0022-3263
EISSN: 1520-6904

Volume

Issue

Page Numbers

6566-6570

Language

English

PMID

12919016

DOI

10.1021/jo034244o

Abstract

Measurements of pK(a) values for the ionization of alpha-X-substituted ethyl acetates (1, X = NO(2); 2, X = CN; 3, X = SO(2)CF(3)) in H(2)O[bond]Me(2)SO mixtures and pure Me(2)SO show a unique response of the acidity of the SO(2)CF(3) derivative to the solvent changes, thereby resulting in a remarkable inversion in the acidifying effects of the strongly electron-withdrawing NO(2) and SO(2)CF(3) groups on going from H(2)O to Me(2)SO. Overall, the results obtained provide strong evidence that the powerful electron-withdrawing effect of the SO(2)CF(3) group is by far the result of polarization effects rather than other factors such as negative hyperconjugation.