From In Situ Crystal Seed Generation to Chirality Control: Stage-Specific Irradiation by Plasmon-Coupled Circularly Polarized Light and High Enantioselectivity

The synergy between localized surface plasmon resonance (LSPR) of nanoparticles and circularly polarized light (CPL) is expected to achieve enantiocontrol by amplifying the chiral electromagnetic field of CPL. In prior studies, through the combination of highly focused CPL via optical tweezers and lithographic LSPR-active nanostructures, full-time irradiation in chiral crystallization enabled enantiocontrol, with a crystal enantiomeric excess (CEE) reaching 56%. To explore a more feasible and effective strategy, we developed a two-stage crystallization approach for NaClO₃ and tetraphenylethylene (TPE), where plasmon-coupled CPL was applied exclusively for in situ crystal seed generation. High enantioselectivity was achieved: 79-100% CEE for NaClO₃, and 52% and -44% batch-to-batch enantioselectivity for TPE, implicating a nucleation-governed and seed-amplification mechanism for the enantiocontrol of CPL. Meanwhile, chemically synthesized nanoparticles and direct CPL irradiation (for TPE) were employed, suggesting an easier protocol. This work provides a practical and efficient enantiocontrol strategy driven by plasmon-coupled CPL, with the advantages of minimal CPL irradiation and a simplified plasmonic optical setup.