Persistent Chiral Diradicals via SUMO–LUMO Inversion: Modular Synthesis, Electronic Structures, and Redox‐Switching Properties

ABSTRACT Integrating chirality into organic open‐shell architectures holds immense promise for molecular spintronics and advanced optoelectronics. However, achieving simultaneous chemical persistence, configurational stability, and practical synthetic accessibility remains a formidable challenge. Here, we report a modular strategy for persistent singlet chiral diradicals based on a C 2 ‐symmetric bibenzo[ g ]quinoline scaffold. Enantiopure π‐extended precursors were efficiently synthesized via a one‐pot multicomponent Povarov cyclization from commercially available BINAM, bypassing chiral HPLC resolution. Upon reduction, the monoradical intermediates exhibit a rare singly unoccupied molecular orbital SUMO–LUMO inversion (SLI) electronic configuration. Strategic N‐protonation and steric shielding at high spin‐density sites dramatically enhance stability while preserving the SLI character, enabling unambiguous assignment of a singlet ground state of the reduced chiral diradicals. The resulting diradicals can serve as robust chiral redox switches, enabling highly reversible, fatigue‐free electrochemical cycles between the closed‐shell dication and neutral diradical states with full retention of the embedded chiroptical information. This work demonstrates successful implementation of the SLI pathway for persistent chiral diradicals and provides a practical platform for the rational design of configurationally stable, redox‐tunable open‐shell materials with tailored electronic and chiroptical properties.