Preparation and electrical properties of poly(3‐thienylacetylene)

Abstract

Abstract3‐Thienylacetylene (1) was prepared by reaction of 3‐(2,2‐dichloro‐1‐fluorovinyl)thiophene with butyllithium in a 1 : 2 mole ratio, and subsequent hydrolysis. Polymerization of 1 with WCl6 and tetraphenyltin gave poly(1), poly[1‐(3‐thienyl)vinylene], which contained a small amount of benzene‐insoluble product. On heating poly(1) no weight loss was observed up to 240°C. At 500°C the weight loss was 18%. In differential scanning calorimetry, an exothermic peak appeared at 245°C. A pressed pellet, doped with iodine, exhibits conductivity of about 10−3 S/cm. The absorption spectrum of poly(1) shows a shoulder at 225 nm, a maximum absorption at 360 nm and tailing up to about 660 nm. In a solution of poly(1) and I2, a new absorption appeared in the near‐infrared region, but failed to develop enough to suggest high conductivity of poly(1) doped with iodine. The electrochemical doping of poly(1) and electrochemical polymerization of 1 gave no conducting products.