Molecule‐Engineered Triarylamine Polymers: Tailoring Multifunctional Optoelectrochemical and Energy‐Saving Applications

Electrochromic materials could modulate optical properties via applied voltage and are integral to smart windows, displays, and energy‐efficient devices. This study presents molecule‐engineered triarylamine‐based non‐conjugated polyamide (A‐NCP) for multifunctional optoelectrochemical and energy‐saving applications. Four polyamides are synthesized, and all exhibited excellent electrochromic behaviors and properties. Among them, the terephthalamide‐bridge triarylamine polyamide reveals a significant bathochromic shift of nearly 300 nm compared to the conventional phenyl π‐bridge in the cation radical form, extending intervalence charge‐transfer (IV‐CT) absorption into the NIR‐II region (1246 nm) and demonstrating broadband absorption across visible to NIR‐II wavelengths, high optical contrast ratios, and rapid response times. Notably, it enables monitoring residual capacity via absorption changes via blue, orange, NIR‐I, and NIR‐II light sources in electrochromic supercapacitors. Beyond light‐absorption monitoring, light‐emission monitoring could also be achieved by integrating electrofluorochromism with supercapacitors, enabling whole‐day monitoring capabilities. Furthermore, broadband NIR absorption effectively suppresses heat penetration and mitigates water temperature which increases from 11.2 °C to only 3.2 °C at room temperature and atmospheric pressure. These findings position these molecule‐engineered terephthalamide‐bridge triarylamine derivatives as promising materials for up‐and‐coming next‐generation multifunctional optoelectrochemical and energy‐saving applications.