Synthesis and electro-optical properties of conjugated ionic polymers

A new ionic conjugated polymer, poly(2-ethynyl-N-methylpyridinium iodide) (PEMPI), was synthesized by the direct polymerization of 2-ethynylpyridine and methyl iodide under mild reaction condition. Another similar conjugated polymer with different counter-ion, poly(2-ethynyl-N-methylpyridinium tetraphenylborate) (PEMPTPB) was also prepared by the ion-exchange reaction of poly(2-ethynyl-N-methylpyridinium iodide) using sodium tetraphenylborate. The polymer structures were characterized by various instrumental methods to have conjugated polymer system with pyridyl moieties of different counter-ion. The photoluminescence spectra of these polymers having different counter-anions indicated that there is no different inductive and size effects of counter-anion between iodide and tetraphenylborate anions in this conjugated polymer backbone.