Tuning Photoluminescent Wavelength of Water-Soluble Oligothiophene/Polymer Complex Film by Proton Bonding

We synthesized a new oligothiophene derivative with pyridine end groups and investigated their optical properties. Upon adding an aqueous polystyrene sulfonic acid solution, it forms homogeneous polymer complex films with protonated structure. Furthermore, reversible color change in photoluminescence in response to a base due to reversible protonation of pyridyl end groups in oligothiophene was demonstrated, which can be applied to acid sensors.