Synthesis and characterization of a bipyridine-containing electroluminescent polymer with well-defined conjugation length

Poly[5-(1,8-octanedioxy-1,4-phenylene-1,2-ethenylene)-5′-(1,4-phenyle ne-1,2-ethenylene)-2,2′-bipyridinylene] constituted of alternating conjugated rigid block containing bipyridine moiety and nonconjugated flexible alkyl chain was synthesized by the Wittig reaction. The rigid block was linked to flexible alkyl chain spacer by ester group. The chemical structure of the resulting polymer was characterized by FT-IR, ¹H NMR, Gel permeation chromatography, and elemental analysis. The polymer showed high thermal stability and good solubility in common organic solvents. The polymer emitted bright green light centered at 496 nm with an optical band gap of 2.65 eV. The electrochemical behavior indicated that the polymer is an n-type electroluminescent material.