Reviving optically-deficient CsPbCl₃: Ce³⁺/chiral-ligand synergy enables visible-light-driven radical cascades

Perovskite nanocrystals (NCs) have attracted attention as a potential platform for light-driven chemical conversion, owing to their favorable photoelectric properties, structural tunability, abundant surface active sites, and possible chiral synergy. However, their wide bandgap and high carrier recombination result in insufficient photoactivity. Additionally, the sensitivity of the ionic lattice and facile ligand desorption lead to structural instability, presenting a dual challenge for practical applications. In this study, we synthesized the Ce³⁺ doped CsPbCl₃ stabilized by a pair of chiral S/R-Nap ligands bearing double quaternary ammonium salt functional groups (designated as S/R-Nap-CsPb_0.85Ce_0.15Cl₃). These NCs exhibit stable visible-light responsiveness and function as efficient electron transfer relays to suppress carrier recombination, owing to the presence of Ce⁴⁺/Ce³⁺ redox shuttles. Moreover, the robust quaternary ammonium groups within the chiral S/R-Nap ligands form a bidentate Pb²⁺/Ce³⁺ interfacial structure in S/R-Nap-CsPb_0.85Ce_0.15Cl₃. This structural configuration induces local lattice distortion, thereby generating a measurable circular dichroism signal. Simultaneously, energy transfer between the S/R-Nap chiral ligands and CsPb_0.85Ce_0.15Cl₃ NCs, coupled with electron spin polarization arising from chiral microenvironments, promotes charge separation. Consequently, the obtained chiral perovskite NCs exhibit promising catalytic performance in the radical cascade cyclization of N-phenylmaleimide and N-phenylglycine in dichloroethane under violet LED (400-410 nm) irradiation, achieving substrate conversion rates exceeding 70%. This work offers an approach to fabricating stable chiral perovskite NCs through the synergistic integration of ion doping and surface ligand engineering. Furthermore, it provides a versatile platform for visible-light-driven chemical conversions, with potential applications in chiral catalysis and related fields.