Time-resolved fluorescence of p-dimethylaminobenzonitrile in mixed solvents

Abstract

The time-resolved fluorescence decay of p-dimethylaminobenzonitrile (DMABN) in mixed non-polar–polar solvents has been studied. The data cannot be described by an equilibrium between two excited-state species, even when transient terms in the reaction rate constant are considered. The data are analysed in terms of a distribution of DMABN–solvent complexes decaying with a corresponding distribution of rates. The origin of this behaviour, and its implications for understanding the solvation dynamics of DMABN–polar solvent systems, are considered.