Solvent sensitivity of  ortho  substituent effect on  13 C NMR chemical shift of the carboxyl carbon ( δ  co ) in benzoic acid | Zendy

Sen Gupta Susanta K. | Zendy; Shrivastava Ruchi | Zendy

Premium

Solvent sensitivity of ortho substituent effect on 13 C NMR chemical shift of the carboxyl carbon ( δ co ) in benzoic acid

Author(s) -

Sen Gupta Susanta K.,

Shrivastava Ruchi

Publication year - 2011

Publication title -

magnetic resonance in chemistry

Language(s) - English

Resource type - Journals

SCImago Journal Rank - 0.483

H-Index - 72

eISSN - 1097-458X

pISSN - 0749-1581

DOI - 10.1002/mrc.2802

Subject(s) - chemistry , substituent , steric effects , solvent , solvent effects , benzoic acid , chemical shift , carbon 13 nmr , solvent polarity , organic chemistry , dipole , medicinal chemistry , computational chemistry

A reverse ortho effect is observed for the 13 C NMR chemical shifts of the carboxyl carbon ( δ co ) in benzoic acids measured in aprotic solvents of varying polarity. The ortho effect on δ co is best described by a combination of the reverse field and steric accelerating effects of the substituent in an 80: 20 pattern in apolar aprotic solvents and a 60: 40 pattern in dipolar aprotic ones. Interestingly, no good enough correlation was found between δ co and log k 1 of the acids measured in similar solvents. A critical analysis of the results clearly indicates the use of an apolar aprotic solvent and not a dipolar aprotic one as the solvent of choice for investigating intrinsic substituent effects on δ c in an aromatic system. Copyright © 2011 John Wiley & Sons, Ltd.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here

Accelerating Research