Spectroelectrochemistry of poly(ethylenedithiathiophene)--the sulfur analogue of poly(ethylenedioxythiophene).
Poly(3,4-ethylenedithiathiophene) (PEDTT) is a polythiophene-like conjugated polymer in which each thiophene ring is functionalized with an ethylenedithia bridge. As such, PEDTT is the sulfur analogue of the well-known poly(3,4-ethylenedioxythiophene) (PEDOT). Substituent effects, namely the presence of sulfur atoms in PEDTT replacing the oxygen atoms of PEDOT, do not provide a simple explanation for the different electronic properties of the two polymers in the neutral state. This paper reports the spectroscopic properties of PEDTT, studied by in situ techniques such as IR-, Vis-, and electron spin resonance (ESR) spectroelectrochemistry. The differences observed upon electrochemical oxidation of PEDTT and PEDOT (e.g., the different infrared active vibrational band patterns in IR spectroelectrochemistry as well as the different nature of the charged states) are even more marked than those observed in the neutral state. These results, with AM1 calculations, indicate conformational effects as a possible explanation for the different electronic and spectroscopic properties of PEDTT and PEDOT.
Linz Institute for Organic Solar Cells, Physical Chemistry, Johannes Kepler University Linz, 4040 Linz, Austria.
Antonio
A
Cravino
Helmut
H
Neugebauer
Andreas
A
Petr
Peter J
PJ
Skabara
Howard J
HJ
Spencer
Joseph J W
JJ
McDouall
Lothar
L
Dunsch
N Serdar
NS
Sariciftci