Singlet-singlet electronic excitation energy transfer in a bichromophore cooled in a supersonic jet

The fluorescence excitation spectra and polarization of the fluorescence of a bichromophore cooled in a supersonic jet are measured. The bichromophore consists of 2,5-diphenyloxazole (PPO) and 1-(5′-phenyl-1′, 3′-oxazole-2′-yl)-4-(5′-phenyl-1′,3′, 4′-oxadiazole-2′-yl)-benzene (POPDP) connected by the methylene bridge -(CH2)-. Based on the analysis of these components and theoretical calculations, it has been proven that the total intramolecular singlet-singlet transfer of the energy of electronic excitation from the energy donor PPO to the acceptor POPDP occurs in a time of 10-12 sec. © 2005 Springer Science+Business Media, Inc.