Unsymmetrical synthesis of benzimidazole-fused naphthalene imides with panchromatic absorption and redox activity

Abstract: We report a concise synthesis of unsymmetrical benzimidazole-fused naphthalene imide (BfNI) and anhydride (BfNA) derivatives featuring broad UV-Vis-NIR absorption, stable redox activity, and enhanced solubility. Incorporation of triarylamine donors induces strong intramolecular charge transfer and narrows the optical bandgap. This modular design bypasses multistep protection-deprotection and complex pi-assembly, offering a versatile platform for tunable optoelectronic materials.