Novel electrically conducting polyheteroaryiene azines

摘要

In the family of electrically conducting polymers, polythiophenes and their functional derivatives are amongst the most intensely investigated because of the ease of functionalization of thiophene-based monomers by conventional organic methodology and the environmental stability of the resulting polymers both in their doped and undoped state [1-3]. Recent attention has been focused on polymers incorporating conjugative spacers such as vinylene (-CH=CH-) [4,5], ethynyl (-C=C-) [6] and butadienylene [7] moieties into the polymer backbone. These materials are interesting from the viewpoint of reduced bandgap energy as well as enhanced conductivity and solvent processibility of the polymers. In this connection, Amari et cd. [8] have investigated Schiff base containing polymers (1), obtained by the reaction of thiophene-2,5-dicarboxaldehyde with hydrazine, which incorporated azine linkages in the polyarylene backbone. These conjugated molecules are analogous to the butadienylene polymers with the important difference of the prescence of N atoms in place of methine moieties. This difference made the poly-azines more air stable though the two structures are isoelectronic. However, the conductivity of the polymers was very low. In an attempt to improve the electrical conductivity, we investigated the effects of the azines group between the thiophene or furan rings in the novel polymers (2) and (3). The resulting polymers exhibited enhanced electrical conductivity which attained 2.2 X 10-2 S/cm for (2) and 6.6 X 10-3 S/cm for (3) upon doping with I2.