Electronic quenching of pyrene 1B1u by olefins in the vapour phase

Abstract

The rate of quenching of electronically excited singlet pyrene by olefins has been investigated in the vapour phase over the temperature range 420–570 K. Rate constants and activation energies have been determined and correlations with ionization potentials of the quenchers suggest an exciplex intermediate. A model previously proposed for concentration quenching of pyrene has been applied to investigate the temperature and pressure dependence of the rate constant and of the Arrhenius pre-exponential factor. The model is compared with that suggested by Parmenter and co-workers.