Synthesis and photophysical properties of soluble low‐bandgap thienothiophene polymers with various alkyl side‐chain lengths |
| |
| Authors: | Woo Jin Bae Christopher Scilla Volodimyr V Duzhko Won Ho Jo E Bryan Coughlin |
| |
| Institution: | 1. Department of Polymer Science and Engineering, University of Massachusetts Amherst, Conte Center for Polymer Research, 120 Governors Drive, Amherst, Massachusetts 01003;2. Department of Materials Science and Engineering, Seoul National University, Seoul 151‐742, Republic of Korea;3. Energy Frontier Research Center PHaSE, University of Massachusetts, Amherst, Massachusetts 01003 |
| |
| Abstract: | We report the facile synthesis and characterization of a class of thienothiophene polymers with various lengths of alkyl side chains. A series of 2‐alkylthieno3,4‐b]thiophene monomers (Ttx) have been synthesized in a two‐step protocol in an overall yield of 28–37%. Poly(2‐alkylthieno3,4‐b]thiophenes) (PTtx, alkyl: pentyl, hexyl, heptyl, octyl, and tridecyl) were synthesized by oxidative polymerization with FeCl3 or via Grignard metathesis (GRIM) polymerization methods. The polymers are readily soluble in common organic solvents. The polymers synthesized by GRIM polymerization method (PTtx‐G) have narrower molecular weight distribution (?) with lower molecular weight (Mn) than those synthesized by oxidative polymerization (PTtx‐O). The band structures of the polymers with various lengths of alkyl side chains were investigated by UV–vis spectroscopy, cyclic voltammetry, and ultraviolet photoelectron spectroscopy. These low‐bandgap polymers are good candidates for organic transistors, organic light‐emitting diodes, and organic photovoltaic cells. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 |
| |
| Keywords: | conjugated polymers electrochemistry grignard metathesis polymerization low bandgap oxidative polymerization thienothiophene ultraviolet photoelectron spectroscopy UV‐Vis spectroscopy |
|
|
