Synthesis and Characterization of ionic or ionisable octithiophenenes

Oligothiophenes (OTs) are materials with a precisely defined chain and conjugation length and they are usually more soluble than polymers and stable in various redox states. OTs are important molecules for applications in electronic devices, such as Field Effect Transistors (FETs), Organic Light-Emitting Diodes (OLEDs), photovoltaic cells, and sensors.2 Derivatisation of PTs with ionic or ionisable groups in the side chains provides internal charge compensation (or self-doping) generated during redox processes,3 as well as imparts water solubility. Thanks to these hydrophilic properties, ionic OTs could be able to interact with different ionic and biological molecules. This characteristic makes them interesting for applications as chemo- and bio-sensors. These applications require water-compatible materials, in the form of conjugated (and sometimes luminescent) polyelectrolytes, able to detect biomolecules through their impact on the conditions, for photoinduced charge or excitation transfer.4