Optical and vibrational studies on single walled carbon nanotubes/short oligo‐para‐methoxy‐toluene composite

Abstract

In a solution state, an oligophenylene prepared by electrochemical oxidation of para-methoxy-toluene exhibited luminescence in the violet-to-blue region. However, in a solid state, a clear red shift was observed as a signature of a supramolecular p-stacking interaction between oligomer chains. In a de-doped state, by chemical reduction, a fine structure in the form of two peaks was observed and luminescence intensity was strongly improved. When mixed with single walled carbon nanotubes (SWNTs), a quenching in the luminescence intensity accompanied by a slight blue shift of the PL peak of the nanocomposite was observed. This implies the shortening of the oligomer's effective p-conjugation length caused by the added amount of SWNTs. A charge transfer in the photo-excited state was also noted. The interaction taking place between the two materials was supported by optical infrared absorption and Raman scattering measurements and then a functionalizing mechanism was proposed.

Electrosynthesis and characterization of oligophenylene deriving from 4-(methoxyphenyl)acetonitrile

“…This result reveals a strong p-staking supramolecular interaction between oligomer's chains in the film state as described previously for other polyphenylènes [31].…”