Synthesis and Properties of an Ionic Conducting Material: In-Situ Preparation of Poly(2-ethynyl-N-iodopyridinium Iodide) and Its Electro-Optical and Electrochemical Properties

Poly(2-ethynyl-N-iodopyridinium iodide) [PEIPI] was easily prepared via in-situ uncatalyzed polymerization of 2-ethynylpyridine by using iodine. The activated acetylenic bond of 2-ethynyl-N-iodopyridinium iodide formed at the initial reaction time was assumed to be susceptible to linear polymerization, followed by an identical propagation step that contains the produced macroanion and quaternized monomeric species. The polymer structure was characterized by various instrumental methods to have the conjugated polymer backbone system bearing the designed substituents. The electro-optical and electrochemical properties of polymer were studied. The UV-visible spectrum of PEIPI showed a characteristic absorption peak in the visible region up to 800 nm. The PL emission spectrum of PEIPI shows two peaks at 515 and 550 nm. The cyclic voltammetry of PEIPI exhibited irreversible electrochemical behavior between the oxidation and reduction peaks.