Exciplex formation in aromatic copolymers and photoinduced electron transfer from exciplex to acceptor

Abstract

AbstractThe exciplex formation in 9‐vinylphenanthrene‐p‐N,N‐dimethylaminostyrene copolymers, its characteristics, and the electron transfer process in polar solvents were studied. The copolymer exhibited a more intense intramolecular exciplex fluorescence than the low‐molecular‐weight model system, phenanthrene‐N,N‐dimethylaniline, in which the intermolecular exciplex formation occurred. Intensities of the exciplex fluorescence, which were unchanged regardless of the copolymer composition, led us to speculate that the efficient energy migration takes place from an excited phenanthrene unit to an exciplex forming site on the polymer chain. The electron transfer in the copolymer‐p‐dicyanobenzene system was studied in polar media. The formation of p‐dicyanobenzene anion radical was measured by flash photolysis and electron spin resonance (ESR). p‐Dicyanobenzene anion radical was generated by the electron transfer process via exciplex and the direct electron transfer process from the excited phenanthrene unit in the copolymer.