Model calculations on hydrocarbon radiolysis. Part 2.—Excited states in solutions of aromatics in alkanes

Abstract

Model calculations are presented for spurs containing up to five ion pairs; reaction dynamics are treated by the independent pairs approximation. The effect of encounters on the spin wavefunction are treated explicitly; it is assumed that the overall spin state of the spur remains singlet during its 10 ns lifetime. The dependence of solute fluorescence and triplet yields on spur size and solute concentration are calculated and compared with measurements made with vacuum ultraviolet excitation. Spur size distributions are used to estimate G values for fast electron excitation. Predictions are also made of the development of magnetic field effects on recombination luminescence of long-lived ion pairs. The results suggest that excited-state quenching by radicals and radical ions is a major process in spurs.