Electrochemical Polymerization and Properties of Poly(triphenylene), an Excellent Blue-Green-Light Emitter

Abstract

Semiconducting polytriphenylene (PTP), a bright blue-green-light emitter, with good electrochemical behavior, excellent thermal stability, and the electrical conductivity of 10−3 S cm−1 was synthesized successfully by direct anodic oxidation of triphenylene (TP) in different media. The oxidation potential onset of TP in boron trifluoride diethyl etherate containing 3% concentrated sulfuric acid (SA) was reduced to 0.94 V, compared with other electrolyte media. The possible structure of the obtained PTP was investigated by ultraviolet−visible spectroscopy, Fourier transform infrared spectroscopy, and 1D and 2D NMR techniques, respectively. The results showed that the PTP was grown via the coupling of the monomer mainly at the meta position of the benzene ring in TP. Fluorescence spectra indicated that the electrochemically polymerized PTP was an excellent blue-green-light-emitting material with fluorescence quantum yield as high as 0.43. In addition, the morphology and thermal stability of the polymers were also explored by means of scanning electron microscopy and thermal analyzer. The average molecular weight (19 980 g mol−1) and its polydispersity of dedoped PTP were determined by gel permeation chromatography.