A Polyacetylene via the Uncatalyzed Polymerization of 2-Ethynylpyridine Using 3-(Trimethylsilyl)propargyl Bromide: Synthesis and Characterization

Abstract

A new ionic polyacetylene (PA) was synthesized in high yield via the uncatalyzed polymerization of 2-ethynylpyridine using 3-(trimethylsilyl)propargyl bromide. The activated acetylenic triple bond of N-substituted-2-ethynylpyridinium bromide, formed by the reaction of 2-ethynylpyridine and 3-(trimethylsilyl)propargyl bromide, was susceptible to linear polymerization, followed by an identical propagation step that contains the produced macroanion and quaternized monomeric species. The chemical structure of polymer was characterized by NMR (¹H-, ¹³C-), IR, and UV-visible spectroscopies. This polymer showed characteristic wide UV-visible absorption band and green PL maximum value at 518 nm, which is corresponding photon energy of 2.39 eV. The cyclic voltammogram of polymer revealed that it shows stable electrochemical window in the range of of −1.85 V to 1.55 V.

Keywords:

• Polyacetylene
• 2-ethynylpyridine
• 3-(trimethylsilyl)propargyl bromide
• photoluminescence
• cyclic voltammetry

Acknowledgments

The authors thank Mrs S. E. Chae of Korea Basic Science Institute-Taegu Branch for the measurement of 500-MHz FT-NMR spectra of polymers.

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded from the Ministry of Education, Science and Technology (MEST) of Korea (No. 20110028320, 2012001846).