Quenching of an intramolecular naphthalene-triethylamine exciplex by tetrabutylammonium perchlorate. Evidence for the formation of an emissive complex

The fluorescence quenching of the intramolecular exciplex formed by 1-(1-naphthyl)-2-N,N-diethylaminoethane (1N2NE) and tetrabutylammonium perchlorate (TBAP), was studied in 1,4-dioxane, tetrahydrofuran (THF) and acetonitrile (ACN). The quenching efficiency depends on the solvent polarity, the order being dioxane > THF > ACN. Using time-resolved fluorescence spectroscopy, the formation of a reversible fluorescent complex between the intramolecular exciplex of 1N2NE and TBAP in THF as solvent was observed. A model for the quenching mechanism of exciplexes by tetralkylammonium salts is discussed. The kinetics parameters for the quenching of 1N2NE by TBAP are also given.