Kinetics of luminescence spectra of rigid dye solutions due to directed electronic energy transfer

Abstract

The nanosecond shift in flourescence spectra of 3-amino-phtalimide and 4-amino-N-methylphtalimide molecules in pure monomer rigid solutions with high concentrations is found. A decrease of fluorescence duration in the blue region of the emission spectrum and an increase in the red one was observed under similar conditions. The above characteristics were found to be dependent on the wavelength of fluorescence excitation λ ex. The results are proved to be due to the directed non-radiative transfer of electronic excitation between the orientationally broadened electronic states of dye molecules. The experimental results were obtained using a nanosecond laser spectrofluorimeter incorporating a tunable dye laser and an analog minicomputer.