Preparation and Electrochemical Behavior of Quinoxaline-Bridged Diphenylamines

N-Phenylindroquinoxalines (PhIQs), which have a bridged diphenylamine structure, were synthesized and their physical and chemical properties were investigated. Syntheses of the materials were carried out by dehydration condensation between 4,5-disubstituted-1,2-phenylenediamine derivatives and N-phenylisatin. PhIQs showed fluorescent solvatochromism. PhIQs contain a diphenylamine moiety, but exhibit n-type properties due to the introduction of an electronegative quinoxaline unit. Introduction of substituents at the 2- and 3-positions of PhIQ can regulate the reduction-oxidation potentials of the compound. The first reduction potential and fluorescent lambda(max) vs. Hammett's sigma(p) value has a good linear correlation.

Automated summary

N-Phenylindroquinoxalines (PhIQs) with bridged diphenylamine structure were synthesized and studied, showing fluorescent solvatochromism and controllable reduction-oxidation potentials of the compound.