Synthesis and Properties of 5,8-bis(3,4-Ethylenedioxythiophenyl) Acenaphthenequinox-Based Copolymers Containing Phenylene Ethynylene Unit

A new monomer 5,8-bis(5′-bromo-3,4-ethylenedioxythiophenyl)-acenaphthenequinoxaline was synthesized and its conjugated copolymer, poly(2,5-didodecyloxy-1,4-diethynylphenylenealt5,8bis(3,4ethylenedioxythiophenyl)-acenaphthenequinox) (PI) and poly(2,5-diheptyloxy1,4-diethynyl-phenylene-alt-5,8-bis(3,4-ethylenedioxythiophenyl)-acenaphthenequinox) (PII) were obtained by Sonogashira reaction with 1,4-diethynyl-2,5-dialkoxybenze. Both monomer and polymers were characterized by 1H-NMR and FT-IR spectroscopy. Results show that these two polymers have similar optical properties with UV-Vis absorption peak at 490 nm, and PL emission peak at 613 nm. Copolymers have good thermal stability and were electrochemically active. They give reversible two redox peaks in the potential region of -1.0—2.0 V with a color change of the polymer film from red to deep blue.