6-Propionyl-2-(N,N-dimethylamino)naphthalene (PRODAN) Revisited

Abstract
The photophysics of 6-propionyl-2-( N,N-dimethylamino)naphthalene (PRODAN) in liquid water are reported. Our results demonstrate that the often mentioned extra blue-edge shoulder seen for PRODAN in liquid water is a result of PRODAN—PRODAN intermolecular interactions in a supersaturated PRODAN solution and not a consequence of impurities in the commercial PRODAN preparations. In all cases where the aqueous PRODAN solution is not supersaturated, there is no detectable blue-edge emission shoulder.