ESR Studies of Nitrogen-centered Free Radicals, N-Aryl-N-phenylthioaminyls

Abstract A variety of substituted N-phenyl-N-phenylthioaminyls (2), Ar–\dotN–S–Ar′, were generated by the photolysis of benzenesulfenanilides (1) in benzene in the presence of di-t-butyl peroxide or by the oxidation of 1 in benzene with lead dioxide. The ESR spectra of the radicals were completely analyzed by labeling some radicals with deuterium and with the aid of a computer simulation technique. The unpaired electron is distributed mainly on the nitrogen atom and the N-phenyl ring. The values of an were plotted against the σ or σ− in the Hammett equation, and it was found that 2, in terms of Walter’s criteria, belong to class S.