Unveiling the unusual halochromic response and phase behavior of a dihydropyrrolo[3,2-b]pyrrole electrochrome

A carbazole-functionalized pyrrolo[3,2-b]pyrrole (Cbz-DHPP) chromophore was synthesized, exhibiting high-contrast electrochromism, strong blue fluorescence, halochromism, and polymorphism. These findings advance understanding of DHPP structure–property relationships, while introducing new electrochromic colors and the first examples of halochromism and mesomorphic properties in DHPP-based materials, highlighting their potential in optoelectronic applications.