Excited state intramolecular proton transfer dynamics of semi-rigid polyquinoline in solution and polymer film

Dynamics of the excited state intramolecular proton transfer of a polyquinoline in solution and polymer film has been studied by time-resolved fluorescence. The proton transfer occurs rapidly in both solution and polymer film at 130 and 55 fs, respectively. In solution, however, the dynamics is quite dispersive, as the 130 fs component comprises 30% of the fluorescence decay and the remainder at slower rates. The dynamics is homogeneous in the polymer film. The dynamics are consistent with the stationary fluorescence spectra reported previously. Conformational heterogeneity in the dihedral angle is invoked to account for the dispersive dynamics.