Transient photophysics of phenothiazine–thiophene/furan copolymers in solvents

The steady-state and transient photophysics of a series of newly synthesized phenothiazine-based conjugated polymers and copolymers with thiophene and furan moieties in solvents were investigated. Positive solvatochromism in emission spectra was observed in polar solvents due to excited-state intramolecular charge-transfer. The picosecond time-resolved spectra using streak camera revealed fast chain twisting motion at ∼10 ps, verified by solvent viscosity dependency. A non-radiative de-activate pathway is assigned to the non-planar conformation at excited state. This reveals a possible way for intramolecular energy loss in new polymer design for applications.