Time-resolved fluorescence excitation spectroscopy of styrenes

Abstract

The time-dependent photophysical processes occurring in low pressures of styrene and trans-1-phenylprop-1-ene vapours have been investigated as a function of excitation wavelength using synchrotron radiation from the Orsay Storage Ring (ACO). Earlier observations made with an Argon Ion laser have been confirmed and it has been found that the fluorescence lifetimes of the observed dual emissions show a strong dependence on excitation wavelength. Quantum yield measurements have enabled trends in the sum of the nonradiative processes from S1 and S2 to be followed for the two styrenes studied. The results have been interpreted in terms of the population of a twisted excited state on excitation t..