New triphenylamine-based poly(amine-imide)s with carbazole-substituents for electrochromic applications

A series of new poly(amide-imide)s (PAIs) with carbazole-substituted triphenylamine units were prepared by direct polymerization from the new diimide-diacid and various aromatic diamines. The PAI-7a film possesses excellent stability of electrochromic characteristics for the radical cations generated, changing color from original pale yellowish neutral form to the green and then to dark blue oxidized forms. Furthermore, the anodically coloring of PAI-7a shows high coloration efficiency (CE = 205 cm2/C), high contrast of optical transmittance change (ΔT = 80% at 776 nm) and long-term redox reversibility.