Electro-optical properties of poly(N-alkyl-2-ethynylpyridinium bromide)s

Poly(N-alkyl-2-ethynylpyridinium bromides)s with different alkyl chains were synthesized in high yields by the activated polymerisation of 2-ethynylpyridine with various alkyl bromides in the absence of any additional initiator or catalyst. The polymer structures were characterized by various instrumental methods such as NMR, IR, and UV-visible spectroscopies to confirm the conjugated polymer backbone system having N-alkylpyridinium moieties. The polymers were completely soluble in such organic solvents as DMF, DMSO, and DMAc. The photoluminescence spectra of poly(N-dodecyl-2-ethynylpyridinium bromide) and poly(2-ethynyl-N-octadecylpyridinium bromide) showed that the photoluminescence peaks are located at 600 and 596 nm corresponding to the photon energy of 2.07 and 2.08 eV, respectively.