Synthesis of n-Type π-Conjugated Polymers with Pendant Crown Ether and Their Stability of n-Doping State against Air

Abstract

The n-type π-conjugated polymers with a 1,2,4-triazole ring substituted by a benzo-15-crown-5-ether (benzo15C5) subunit at the 4-position of the 1,2,4-triazole ring were synthesized by organometallic polycondensations. The UV−vis spectra of the polymers exhibited absorption maxima (λmax values) at a longer wavelength than that exhibited by 4-benzo15C5-1,2,4-triazole (model-1), revealing that their π-conjugation system was expanded along the polymer chain. The electric conductivity measurements suggested that model-1 formed inclusion adducts with 1:1 and 2:1 molar ratios with Na+ and K+, respectively. Addition of KClO4 to the DMSO solutions of the polymers with the benzo15C5 subunit caused the formation of the 2:1 inclusion between the 15C5 ring and K+; this inclusion led to a bathochromic shift in λmax of the polymers. In addition, photoluminescence intensity of the polymers decreased after the addition of KClO4 to solution. The polymers with the benzo15C5 subunit underwent an electrochemical reduction (n...