Elaboration and characterization of donor–acceptor polymer through electropolymerization of fullerene substituted N-alkylcarbazole

An intrinsic ambipolar molecule, containing carbazole (electron donor) and fullerene (electron acceptor) moieties bonded to each other by a hexyl group, has been synthesized and characterized. Cyclic voltametry revealed the presence of electroactive fullerene moieties during electroreduction. The fluorescence quenching of the Cbz-C60 donor–acceptor monomer has been studied and compared to a mixture of N-hexylcarbazole and C60. For the mixture, the photoluminescence quenching was studied with the Stern–Volmer equation and a quite high value of the Stern–Volmer constant KSV of 6.6 × 104 M−1 at wavelength excitation of 290 nm is obtained. Upon electrochemical oxidation, an electroactive conducting polymer film is formed onto the electrode via 3–6 coupling reactions of carbazole units leading to a double cable structure. Finally, relative energy levels values of the HOMO and LUMO of the donor polymeric backbone and the one of the acceptor pendant moieties were evaluated and the results are compatible with an electron transfer from carbazole to C60 unit.

► The synthesis of an intrinsic ambipolar molecule, containing carbazole and fullerene units bonded by a hexyl group, was realized.
► A polycarbazole-C60 double cable structure was electrosynthezized in thin film.
► HOMO and LUMO energy levels of the donor and acceptor moieties were evaluated.
► Electron transfer from carbazole to C60 unit was evaluated by the Stern–Volmer constant.