Abstract: Poly[3-(ferrocenyl-ethyl formate)triethoxy]thiophene was prepared by chemical polymerization with iron(Ⅲ) chloride as an oxidant. The resulting polymer is soluble in ordinary solvents, such as chloroform, tetrahydrofuran, acetone, xylene, etc.. The polymer structure was further confirmed by NMR and IR. The optical and electrochemical properties were examined by UV-Vis and PL spectroscopies and cyclic voltammetry. It exhibits a maximum of absorption at 553 nm and a maximum emission at 654 nm in chloroform solution, the doped polymers show two broad absorption peaks at 502 and 860 nm, which are characteristic of the presence of bipolarons. In addition, cyclic voltammetric measurements reveal that the ferrocene substituents remain a high redox activity and stability. Moreover, this resulting polythiophene derivative containing tetraethoxy units show a great selectivity and sensitivity towards sodium cation.

Key words: Polythiophenes, Ferrocene, Electroactivity, Noncovalent interaction, Ionic complexing