Redox‐Active and Electrochromic Aromatic Poly(Ether‐Imide)s With Carbazole‐Triphenylamine Chromophores

ABSTRACT A novel bis(ether anhydride) incorporating the carbazolyltriphenylamine (CzTPA) segment, specifically 4,4′‐bis(3,4‐dicarboxyphenoxy)‐4″‐(carbazol‐9‐yl)triphenylamine dianhydride, has been synthesized. Following this, polycondensation with commercially available aromatic diamines led to the formation of a series of electroactive aromatic poly(ether imide)s. All synthesized polymers exhibit excellent solubility in polar organic solvents and can be solution‐cast into smooth, flexible thin films. These poly(ether imides) demonstrate glass transition temperatures ( T g ) ranging from 251°C to 260°C, with no significant thermal degradation observed below 500°C, indicating their impressive thermal stability. Cyclic voltammetry (CV) measurements reveal two oxidation waves at approximately 1.20 and 1.51–1.63 V, respectively. The first redox process is quasi‐reversible, while the second is irreversible. In their neutral state, the cast films appear colorless and transparent, transitioning to pale blue during the first oxidation stage and to light Prussian blue in the second oxidation stage. Furthermore, coupling reactions involving the pendant carbazole units readily occur when the polymers are scanned to 1.8 V during CV measurements. Upon oxidation, the polymer films exhibit moderately high absorption in the near‐infrared region.