Proton Transfer in the Inter- vs Intramolecular Quenching of Naphthol Fluorescence by Amines

Article abstract of DOI:10.1021/j100178a019

"Charge-transfer" quenching of naphthols by amines can occur via either proton transfer or electron transfer.To gain insight into the quenching mechanism, the room temperature photophysics of 2-naphthol (N2) in the presence of a trialkylamine was compared with that of 2-methoxynaphthalene (N2M) and of an intramolecular equivalent, 1-<(dimethylamino)methyl>-2-naphthol (1DMN2).To maintain structural analogy, dimethylbenzylamine (DMBA) was used as the quencher.Comparison of steady-state and time-resolved fluorescence for both intermolecular and intramolecular cases leads to the conclusion that the major quenching pathway involves proton transfer.