Correlation of N.M.R. Chemical Shifts of N-Methyl Protons of Substituted Dimethylanilines with Hammett Substituent Constants

Abstract

The proton magnetic resonance chemical shifts of N-methyl protons in para-substituted NN-dimethylanilines have been correlated with the Hammett σ− value of the para substituent. The correlation yields σ− values of 1.57 ± 0.09 and 0.85 ± 0.09 for the para nitroso and para 4′-dimethylaminobenzoyl substituents, respectively. The solvent shift of the N-methyl protons between chloroform and benzene solutions also fits a linear correlation with Hammett σ−, and yields σ− = 1.52 ± 0.11 for the para-nitroso substituent. © 1966 CSIRO. All rights reserved.