Electrochemical oxidation-induced polymerization of 5,10,15,20-tetrakis[3-(N-ethylcarbazoyl)]porphyrin. Formation and characterization of a novel electroactive porphyrin thin film

The formation and characterization of novel polymer modified Pt and ITO electrodes obtained by electropolymerization is depicted. The presences of porphyrin, a powerful optical and redox active center, together with carbazole, a well-known hole-transporting material, confer to the polymer electric and optical activity, with potential application in the development of organic optoelectronic devices. 5,10,15,20-Tetrakis[3-(N-ethylcarbazoyl)]porphyrin form conductive, stable and reproducible electropolymer films. Combined electrochemical and spectroscopic studies show that the electropolymerization mechanism involves the dimerization of carbazole units. During coupling of carbazole radicals, protons are released to the media and porphyrin film is protonated, generating the porphyrin dication. The observation of the characteristic porphyrin electronic spectrum after reduction of the film indicates that the tetrapyrrolic macrocycle remains unaltered in the electrogenerated polymer. The formation of a broad band that extends into the near-IR region upon polymer oxidation is in agreement with the presence of a conducting polymer with good charge transport capability.

► We show the formation and characterization of a novel porphyrin polymer.
► Its electropolymerization mechanism involves the dimerization of carbazole units.
► The electrogenerated polymer film shows the characteristic porphyrin bands.
► We detect a broad band that extends into the near-IR region upon polymer oxidation.