Synthesis and characterization of poly{1,2-bis(2-seleninyl)ethene}, a novel electrically conductive polymer with diminished band gap

A novel electrically conducting polymer containing selenophene and ethenyl spacer, poly{1,2-bis(2-seleninyl)ethene} (PDSE), has been generated by chemical and electrochemical polymerization. This polymer exhibits a significantly lower band gap (1.61 eV) than polyselenophene and possesses partial solubility in common organic solvents. The electrochemical and optical properties have been thoroughly investigated by cyclic voltammetry and UV-vis spectroscopy. This polymer can be reversibly reduced and oxidized (both n- and p-doped) between -2.0 V and +0.8 V (vs SCE). Chemically doped polymers using chemical reagents such as iodine and ferric chloride afforded materials with a maximum conductivity of 0.27 S cm(-1). Scanning electron micrographs of (ClO4-) doped polymers deposited on indium tin oxide coated glass electrode depict a globular morphology. X-ray photoelectron spectroscopic studies of PDSE were conducted using undoped polyselenophene synthesized from a nickel-catalyzed Grignard cross-coupling reaction as a calibration standard for the Se 3d environment.