An Electron Spin Resonance investigation of the radical cations from Poly(alkylthio)benzenes

The radical cations of some poly(methylthio)- and poly(isopropylthio)-benzenes have been investigated by ESR spectroscopy. Discrimination between the couplings due to the ayrl and alkyl protons, when the assignment is not straightforward, has been made by hydrogen-deuterium exchange of the acidic aryl protons. Oxidation of the title compounds did not lead in all cases to the corresponding cation radicals and in some instances secondary species were observed arising from the fragmentation of the initially formed radicals. The conformational preference of the alkjylthio and isopropyl groups is discussed.