Novel polyindole film prepared via the Meisenheimer complex of indole with trinitrofluorenone

The first electropolymerization of a Meisenheimer σ-complex of indole with 2,4,7-trinitro-9-fluorenone (TNF) has been reported. Linear sweep voltammetry and FT-IR analyses revealed that the electropolymerization is accompanied by the elimination of the TNF moiety from the complex, followed by the linking among the resulting indole units. The generated polyindole film is different from the conventional polyindole film in that the polymer chain consists of indole units linked to the chain via the various positions. In accordance with this unique structure, the former film is characterized by a multi-step redox behavior, flat absorption feature of UV–vis light, higher work function, and lower electric conductivity when compared to the conventional polyindole film.