Resonance Raman studies of para-substituted NN-dimethylaniline free radical cations

Abstract

A series of para-substituted NN-dimethylaniline free radical cations have been formed as reaction intermediates in the chemical oxidation of their neutral parent compounds. The free radical cations all possess intense visible absorptions which have facilitated the excitation of their resonance Raman spectra. The parent-to-radical Raman wavenumber shifts have been interpreted in terms of the structure and bonding changes that occur upon radical formation. The changes observed do not correlate well with the Hammett (σ_p) values for the para-substituents.