P. Buvat, P. Hourquebie
May 5, 1997
Citations
0
Influential Citations
38
Citations
Journal
Macromolecules
Abstract
Regiorandom and regioregular head to tail coupled poly(3-butylthiophenes), poly(3-octylthiophenes) and poly(3-dodecylthiophenes) have been synthesized by direct oxidation of 3-n-alkylthiophenes using FeCl3 as oxidant and by regiospecific dehalogenation of 2-bromo-3-n-alkylthiophenes. NMR characterizations indicated 70% of head to tail couplings in the polymers synthesized by FeCl3 route, and more than 99% for regioselective polymerizations. The results of both the solution and the solid state UV−vis spectroscopic studies showed that all the regioregular poly(3-alkylthiophenes) had a lower π−π* transition energy, characteristic of a longer conjugation length. A series of visible−near-IR spectra of chloroform solution of FeCl3-doped regioregular P3ATs is reported and shows an increase of the maximum absorption energy of doped P3ATs as a function of alkyl side chain; i.e., longer conjugation lengths are observed in the P3AT possessing the longer alkyl side chain. Moreover, the effect of solvent on electronic...