Synthesis and Characterization of a Regioregular Side-Chain Semifluorinated Polythiophene

The synthesis of a new side-chain semifluorinated thiophene monomer obtained by the reaction of 3-thiophene ethanol with 4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononan-1-ol is reported. The side-chain semifluorinated monomer is polymerized using Kumada catalyst-transfer polycondensation to obtain the regioregular side-chain semifluorinated thiophene polymer P3sfT with a sufficiently high molar mass of about 26 000 g mol(-1) and narrow dispersity D of 1.11. The bulk structure is analyzed by X-ray scattering and shows pi-pi stacking as well as the strong formation of layer structures caused by the self-organization of the semifluorinated side chains. The structure is even more pronounced than in P3HT which is due to the extension of the side chains by fluorinated methylene groups. Thin films are prepared from solution in octafluorotoluene and examined for their layer structure using XRR and 2D-GIWAXS. The same structure as in solid state is found, again indicating high self-organization of the semifluorinated side chains. Due to the high self-assembly, the polymer shows potential as semiconductor in organic electronics. Measurements of electronic properties are currently in progress.