resumo
This article reports a thorough spectroscopic characterization and the complete microstructural unravelling of a novel soluble poly(thienylene methylene) recently obtained by a straightforward process based on the methanesulfonic acid-catalyzed self-condensation of 2-acetoxymethyl-3,4-dimethylthiophene. These macromolecules were found to generate both in situ (in the acidic reaction medium) and ex situ (by the addition of appropriate dopants) conjugated sequences consisting of alternating aromatic-and quinoid-like thiophene rings, that is, conjugated thienylene methine sequences. The effect of different types of dopants on the electronic features of these polymers was assessed by the extent of bathochromic shifts they induced in the macromolecule UV-vis spectra. Doped films obtained by solution casting were characterized by dielectric spectroscopy to evaluate their electronic conductivity. The observed low values of conductivity were explained on microscopic basis evidencing the presence of polymer branching. All the structures arising from side reactions responsible for branching were determined by an exhaustive NMR study, which led to the formulation of the corresponding mechanisms. Remarkably, all these polymers, irrespective of their specific structural features and molecular weights, retained complete solubility in common solvents. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 5227-5238, 2011
palavras-chave
ACID-CATALYZED POLYCONDENSATION; DIELECTRIC RESPONSE ANALYSIS; HOPPING CHARGE-TRANSPORT; FIELD-EFFECT TRANSISTORS; POLY(HETEROARYLENE METHINES); MECHANISMS; LINKING; RANGE
categoria
Polymer Science
autores
Stagnaro, P; Panizza, M; Gandini, A; Prevosto, D; Lucchesi, M
nossos autores
Alessandro Gandini
InvestigadorGrupos
agradecimentos
The authors thank F. Sancassan of the University of Genova, A. Boccia of CNR-ISMAC for their support to the NMR experiments, and E. Tamburello of the University of Pisa for helping in experimental work. This work was partially financed by the NANOPACK FIRB-MIUR project RBNE03R78E of the Italian Ministry of Research.