(A) new class of conjugated ionic polyacetylene

Abstract

A new type of conjugated ionic polyacetylene was synthesized by metathesis polymerization with transition metal catalyst. The used monomers were 2-ethylhexyl hexyldipropargylammonium salts having tetraphenylborate, bromide and chloride as counteranions, and the catalyst used in cyclopolymerization showed the different catalytic activity in accord to the counteranion. FT-IR, $^1H$ NMR, $^{13}C$ NMR and UV-visible spectroscopies showed that the obtained polymers possessed polyene structure having cyclic recurring units in the polymer backbone. The resulting polymers were highly soluble in organic polar solvent due to their ionic character and they showed the solution behavior of polyelectrolyte. When doped with an acceptor such as iodine, the polymers exhibited a substantial increase ($\sim10^{-3}$S/cm) in electrical conductivity compared to the undoped state ($\sim10^{-10}$S/cm).