COPOLYMERIZATION OF 2-ETHYNYLPYRIDINE WITH PHENYL-SUBSTITUTED AND HALOGEN-SUBSTITUTED ACETYLENES

2-Ethynylpyridine with phenylacetylene and with halogen-substituted acetylenes was copolymerized using tungsten and molybdenum chlorides with some cocatalysts and tungsten and molybdenum hexacarbonyls. Thermal polymerizations were also run. IR, NMR and UV-Vis spectroscopies and X-ray diffraction were used for characterization of the copolymers. The electrical properties were also measured. The net atomic charges and dipole contributions of 2-ethynylpyridine, phenylacetylene and halophenylacetylenes using molecular orbital theory were calculated. The nitrogen atom increases the electron density of the beta ethynyl carbon which favours the reaction with the positively charged beta carbon of 1-bromo-2-phenylacetylene to produce mostly copolymer. It was found that the type of catalyst does influence the yield of reaction but has no influence on the structure of the copolymers. The copolymers were amorphous and of semiconducting character.