Exciplex Photophysics. V. The Kinetics of Fluorescence Quenching of Anthracene by N,N-Dimethylaniline in Cyclohexane.

摘要

The photokinetics of the fluorescence quenching of anthracene by N,N-dimethylaniline has been investigated by fluorescence decay and steady state techniques. It has been found that the transient effects associated with diffusion-controlled reactions must be taken into account. The forward reaction is diffusion controlled and the kinetic behavior of the system is dominated by exciplex dissociation to yield its precursors and by the exciplex radiative transition. Delta G, delta H, and delta S for the excited state equilibrium at 25 C are -4.6 and -12.1 kcal/mol and -25.2 eu, respectively. The kinetic model commonly used for excimers and exciplexes appears to be obeyed with the stipulation that the time dependence of the rate constant for exciplex formation must be taken into account. Correction methods for transient effects are discussed. (Author)