title: Correlations between structure and far-infrared active modes in polythiophenes.
abstract: We have investigated the experimental X-ray and far-infrared responses of three polythiophenes synthesized from a thiophene, alpha-bithiophene, and alpha-quaterthiophene monomer. The X-ray data show that the crystallinity of the different polythiophene samples depends on the synthesis conditions. An excellent correlation between the crystallinity of polythiophenes and their far-infrared signatures is demonstrated. In addition, the assignment of the far-infrared phonon modes in polythiophenes is given by using both an experimental filiation procedure and first-principles calculations. In particular, the ring libration inside the polymeric chain, directly involved in the electron-phonon coupling, is assigned.
authors.affiliation: Laboratoire de Physique du Solide, Facultes Universitaires Notre-Dame de la Paix, Namur, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Hermet
authors.forename: J-L
authors.initials: JL
authors.lastname: Bantignies
authors.forename: R
authors.initials: R
authors.lastname: Almairac
authors.forename: J-L
authors.initials: JL
authors.lastname: Sauvajol
authors.forename: F
authors.initials: F
authors.lastname: Serein
authors.forename: J-P
authors.initials: JP
authors.lastname: Lère-Porte