Abstract

A (thienylene–dialkoxyphenylene) copolymer has been prepared by using an organometallic condensation reaction between a bis(stannyl)thiophene reagent and a substituted dibromobenzene derivative in the presence of a palladium catalyst. The grafting of 2-butoxyethoxy substituents gave the polymer a good solubility in most organic solvents. Moreover, owing to the presence of polar dialkoxy chains along the conjugated skeleton, a material with excellent glass adhesion properties was obtained. It allows the formation of homogeneous thin films coatings. The material is highly fluorescent (Φ_sol = 0.9, λ_sol = 520 nm). The polymer was ordered by coating on an oriented Teflon deposit on a glass support and exhibited polarized fluorescence. On the other hand, the material presented a stable reversible blue–red electrochromism associated with a redox transfer at a low potential value (0.5 V vs. SCE). Moreover, the electrochromic properties of this material are preserved even in an aqueous electrolytic medium (LiClO₄–H₂O). The copolymer with enhanced optical properties compares quite favorably to polythiophene and has good potential for the elaboration of optical devices; for example it seems to be a good candidate for the preparation of electroluminescent diodes with polarized emission.