ALTERNATING BLOCK-COPOLYMERS INCORPORATING 3-ALKYL-SUBSTITUTED THIOPHENE AND ANILINE REPEAT UNITS - NOVEL ELECTRICALLY CONDUCTIVE AND FLUORESCENT POLYMERS

A series of alternating block copolymers incorporating Li-alkyl-substi tuted thiophene and aniline repeat units (PATBAs): poly{4-[2-(3-methyl ) thienyl]benzenamine} (PMTBA), poly{4-[2-(3-butyl)thienyl]benzenamine } (PBTBA), poly{4-[2-(3-octyl)thienyl]benzenamine} (POTBA) and poly{4- [2-(3-dodecyl)thienyl]benzenamine} (PDTBA) were synthesized via chemic al oxidative polymerization using ferric chloride as oxidant. The resu lting polymers were characterized by FT-IR, W-Vis, fluorescence spectr oscopy, elemental analysis, thermogravimetry and electrical conductivi ty measurements. It was shown that coupling during polymerization occu rred through the a-position of the thienylene ring and the amino moiet y. Upon doping with iodine the polymers attained electrical conductivi ty ranging from 10(-4) to over 10(-3) S cm(-1). The fluorescence quant um efficiency of the polymers in solution was found to decrease with i ncreasing pendant alkyl-chain length. Scanning electron microscopy (SE M) revealed a globular morphology similar to poly[4-(2-thienyl) benzen amine] and polythiophene. (C) 1998 Elsevier Science S.A. All rights re served.