13C NMR Study of ortho-, meta- and para-Substituted Phenylhiphenylamines: Substituent Effect Correlations

Article abstract of DOI:10.1002/mrc.1270150318

The 13C chemical shifts of 11 substituted triphenylamines have been determined and the assignment of these resonances made using intensities, 1H and 19F couplings and predictions from bond additivity relationships. 13C chemical shifts at carbons bearing the substituent and at carbons ortho to the substituent correlated reasonably well with the Q parameter.A multiple regression analysis of chemical shifts with the field and resonance parameters of Swain and Lupton and the Q parameter produced significantly better correlations than those obtained when Q was omitted for these positions. 13C chemical shift correlations for carbons meta and para to the substituent were not significantly better than when Q was omitted.Significant correlations were obtained between field and resonance parameters and 13C chemical shifts of C-o and C-p, and C-i, C-o, C-m and C-p of the non-substituent bearing phenyl rings in ortho- and para-substituted phenyldiphenylamines, respectively.