ABSTRACT
This chapter describes excited-state proton-transfer reactions of aromatic compounds from the following viewpoints: Proton-induced quenching mechanism, Effect of electronic structures on proton transfer reactions, Environmental effects on excited-state proton transfer reactions and Application of excited-state proton transfer reactions. Proton transfer reactions in the excited state of aromatic compounds are elementary processes in both chemistry and biochemistry. A. Weller has pointed out the competition between the rates of proton transfer and the deactivation in the excited state. Proton-induced quenching often plays an important role in acid-base equilibrium in the excited state of aromatic molecules. Substituent effects on proton transfer to water of protonated aniline derivatives have been investigated by picosecond time-resolved fluorescence measurements. Since acid-base reactions are among the most common and elementary chemical reactions, the molecular mechanism of proton-transfer to solvent is of great importance for the understanding of reaction dynamics in solution.
