TRANSFER OF ELECTRONIC EXCITATION-ENERGY IN POLYSTYRENE FILMS DOPED WITH AN INTRAMOLECULAR PROTON-TRANSFER COMPOUND

The transfer of excitation energy from solvent to solute in polystyren e films doped with 2-(2'-hydroxyphenyl)benzothiazole (HBT) which under goes intramolecular proton transfer in excited electronic state has be en studied by employing steady state and time-resolved fluorescence me asurements. The degree of Forster overlap between donor and acceptor m olecule in this system is estimated to be moderate. Energy transfer ef ficiency increases with solute concentration at low concentration rang e and levels off at high concentration, It is observed that the excime r form of polystyrene is largely involved in energy transfer process. Photostability of HBT in polystyrene to UV light is also investigated to get insight into the long wavelength absorption band of HBT which w as observed upon electron radiation.