Differential Förster Resonance Energy Transfer from the Excimers of Poly(N-vinylcarbazole) to Coumarin 153

Abstract

Photophysics of the nonconjugated vinyl polymer poly(N-vinylcarbazole) (PNVC) has been explored in the presence of coumarin 153 (C153) exploiting steady state and time-resolved fluorometric techniques. Dual emission from the two distinct excimers of PNVC adds importance to the study and makes it interesting. The study substantiates the occurrence of Förster resonance energy transfer (FRET) from PNVC to C153. The differential involvement of the two excimers in the energy transfer process has been established. Considering the fact that FRET is a long distance dipole induced phenomenon, this differential effect has been rationalized from a difference in the dipole moments of the two excimers. Determination of the quenching constants reveals an order of magnitude more quenching of the high energy excimer than the low energy one in the presence of the quencher C153.