Electro-optical and Electrochemical Properties of Poly(N-Benzoyl-2-ethynylpyridinium tetraphenylborate)

Abstract

A new conjugated ionic polyacetylene with bulky tetraphenylborate as counter ion was prepared by the ion-exchange reaction of poly(N-benzoyl-2-ethynylpyridium chloride) using sodium tetraphenylborate. Poly(N-benzoyl-2-ethynylpyridium chloride) was prepared in high yield by the activated polymerization of 2-ethynylpyridine with benzoyl chloride without any additional initiator or catalyst. Such instrumental methods as NMR, IR, and UV-visible spectroscopies revealed that the present polymer has a conjugated polymer backbone system having N-benzoylpyridinium tetraphenylborate as substituents. This polymer showed characteristic wide UV-visible absorption band and green PL maximum value at 620 nm, which is corresponding photon energy of 2.00 eV. The oxidation of polymer was slightly started at 0.05 V, where the vinylene unit of the conjugated polymer backbone could be oxidized in the scan and the redox process was irreversible. The kinetics of the redox process of polymer was controlled by the diffusion process.

Keywords:

• 2-ethynylpyridine
• benzoyl chloride
• cyclic voltammogram
• photoluminescence
• polyacetylene
• sodium tetraphenylborate