Energy transfer in organic systems V. Lifetime studies of anthracene-perylene transfer in benzene solutions

The fluorescence response functions of oxygen-free benzene solutions containing 3 x 10 3 >1 anthracene and concentrations of up to 1.2 x M perylene were observed using the phase and modulation fluorometer. The response functions of the directly excited anthracene and perylene fluorescence are simple exponential decay functions, while that of the perylene fluorescence, indirectly excited by energy transfer from anthracene, is the difference of the two exponential decay functions. Stern-Volmer kinetics are applicable because of the statistical 'mixing' of the molecules by diffusion, which increases the effective critical dipole-dipole transfer radius from 31 A to 43 b.