Temporal dependences of dipole moments of prodan molecules

The fluorescence spectra of 6-propyl-2-dimethylaminonaphtalene (prodan), 1-(phenylamino)naphthalene (1-PAN), and 3-aminophthalimide are measured in glycerol with a picosecond resolution. The instantaneous fluorescence spectra and the correlation functions of the time-dependent Stokes shift of the fluorescence spectra of the two latter probes are used to find the time dependence of the dielectric response function of glycerol, which is necessary for calculating the charge transfer kinetics in prodan molecules. Based on the solvatochromism theory and using the experimental dependences of the time-dependent shift of the fluorescence bands for prodan molecules, which are characterized by efficient charge transfer in the excited electronic state, the kinetics of the electric dipole moment of the first singlet state is calculated.