Electrochemical and spectroelectrochemical behavior of 3,4 ',4 '',4 '''-tetraoctyl-5 '''-chloro-2,2 ': 5 ',2 '': 5 '',2 '''-quaterthiophene - a shortchain model compound for regioregular poly(3-alkylthiophene)
M. Lapkowski et al., Electrochemical and spectroelectrochemical behavior of 3,4 ',4 '',4 '''-tetraoctyl-5 '''-chloro-2,2 ': 5 ',2 '': 5 '',2 '''-quaterthiophene - a shortchain model compound for regioregular poly(3-alkylthiophene), J ELEC CHEM, 501(1-2), 2001, pp. 166-172
Electrochemical and spectroelectrochemical behavior of regioregular monochl
orosubstituted tetra(3-octylthiophene) (QT) has been investigated using UV-
vis-NIR, EPR and Raman spectroscopies. The results obtained prove that QT u
ndergoes dimerization to dichlorosubstituted octa(3-octylthiophene) (OT) an
d dynamic EPR spectroelectrochemical experiments combined with cyclic volta
mmetry can help to determine the mechanism of the process. UV-vis-NIR measu
rements made it possible to find electron spectra of the polaron and bipola
ron formed during the oxidation of OT. The suggested mechanism of oxidation
and electrohydrodimerization of QT into OT is corroborated by FT Raman spe
ctroelectrochemical studies, which show significant changes in the position
and intensities of the Raman bands coinciding with the polaronic and bipol
aronic structures of the oligomers. These changes can he interpreted in ter
ms of formation of a quinoid sequence of bonds in the oxidized oligomers. (
C) 2001 Elsevier Science B.V. All rights reserved.