Uncatalyzed synthesis and characterization of a water-soluble polyacetylene: poly[2-ethynyl-N-(propylsulfonate)pyridinium betaine].

A new ionic conjugated polymer was prepared by the activated polymerization of 2-ethynylpyridine with the ring-opening of 1,3-propanesultone without any additional initiator or catalyst. This polymer was characterized by various instrumental methods to have conjugated polymer backbone system with pendant N-propylsulfonate functional groups. The photoluminescence spectrum of polymer showed that the PL peak is located at 552 nm corresponding to the photon energy of 2.25 eV. The cyclovoltammograms of polymer exhibited the irreversible electrochemical behaviors between the oxidation and reduction peaks. The oxidation current density of polymer versus the scan rates is approximately linear relationship in the range of 30-120 mV/sec. It was found that the kinetics of the redox process is almost controlled by the reactant diffusion process from the oxidation current density of polymer versus the scan rates.