Viologen embedded polyaromatic hydrocarbons (VPAH 2+ ): synthesis, computational, photophysical, and electrochemical characterizations of 3,8-diazaphenanthrenyl viologens

Abstract Several new dicationic viologen sensitizers are synthesized and characterized both photo- and electro-chemically. Benzo-annulation of methyl viologen increases its fluorescence lifetime by a factor of 6.6. Similar lifetime increases were observed for methylated derivatives, that have the added advantage of enhanced solubilities. These electron transfer sensitizers can oxidize organic substrates with oxidation potentials of approximately 2.4 eV and lower.