Solution-Processable Novel Near-Infrared Electrochromic Aromatic Polyamides Based on Electroactive Tetraphenyl-p-Phenylenediamine Moieties

A series of solution-processable near-infrared (NIR) electrochromic aromatic polyamides with N,N,N′,N′-tetraphenyl-p-phenylenediamine (TPPA) units in the backbone were prepared from the phosphorylation polyamidation reactions of a newly synthesized diamine monomer, N,N′-bis(4-aminophenyl)-N,N′-di(4-methoxylphenyl)-1,4-phenylenediamine, with various aromatic dicarboxylic acids. These polymers were readily soluble in many organic solvents and showed useful levels of thermal stability associated with high glass-transition temperatures (236−246 °C) and high char yields (higher than 58% at 800 °C in nitrogen). The polymer films showed reversible electrochemical oxidation with high contrast ratio both in the visible range and NIR region, which also exhibited high coloration efficiency (CE), low switching time, and the highest stability for long-term electrochromic operation to date. At the first oxidation stage, the polyamide Ib thin film revealed high coloration efficiency in visible (CE = 388 cm2/C) and NIR (...