N′-Dialkyl-pyrazinium and -quinoxalinium radicalcations have been isolated as stable iodide or tetraphenylborate salts. E.s.r. spectroscopy of these materials reveals delocalization of seven π electrons in the 1,4-diazine ring, but no intermolecular spin-pairing in the solid state, results which are supported by structural data for the pyrazinium radicalcation salt. The thermodynamic stability and chemical