Conjugated organic polymer from the uncatalyzed polymerization of 2-ethynylpyridine via the ring-opening of 1,3-propandiol cyclic sulfate

•We synthesized a new conjugated ionic polymer via non-catalyst polymerization.•The conjugated polymer backbone system was confirmed by instrumental analysis data.•The photoluminescence peak is located at 525 nm, corresponding to a photon energy of 2.36 eV.•This material showed the well-defined and stable redox process.

A new ionic conjugated polymer was synthesized via the uncatalyzed polymerization of 2-ethynylpyridine by the ring-opening of 1,3-propandiol cyclic sulfate. The polymerization of 2-ethynylpyridine by using 1,3-propandiol cyclic sulfate proceed well in homogeneous manner even at the mild reaction conditions to give a high yield (83%) of polymer. The polymer structure was characterized by various instrumental methods to have conjugated polymer backbone with the designed substituents. This betaine polymer was soluble in polar orgainc solvents. The photoluminescence spectrum of polymer showed that the PL peak is located at 525 nm corresponding to the photon energy of 2.36 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/s. It was found that the kinetics of the redox process of polymer is almost controlled by the reactant diffusion process from the oxidation current density of polymer versus the scan rates.

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