Photoluminescence and electroluminescence characteristics of new disubstituted polyacetylenes

Three di-substituted acetylenes in the tolane structure, 4-(trans-4-pentylc yclohexyl)-3',4'-difluorotolane (1M), 4-(trans-4-heptylcyclohexyl)-4'-fluor otolane (2M), and 4-(4-pentylphenyl)-4'-fluorotolane (3M), were polymerized in the presence of TaCl5-based catalyst. The weight-average molecular weig hts Mw of the polymers were high than 4 x 10(5). Photoluminescence (PL) and electroluminescence (EL) of the three polymers made as single-layer device on indium-tin oxide glass (ITO), ITO/polymer/Al, have been comprehensively studied. By changing the structural conditions of polymer, such as introdu cing the fluorine atom or a long carbon chain to the end group of polymer s ide chains, the luminescence is clearly enhanced.