Light-Gated Circularly Polarized Luminescence Switching via Coordination-Driven Assembly of a Chiral Terbium–Spiropyran System

Achieving spatiotemporal control over photonic functions within a unified materials platform is a central goal for developing adaptive and secure information technologies. Herein, we report a light-gated dynamic coordination assembly that integrates a chiral spiropyran photoswitch with a terbium(III)-terpyridine complex. Upon UV irradiation, the spiropyran-to-merocyanine transformation triggers supramolecular polymerization via Tb3+–phenolate coordination process, which synergistically enables efficient Förster resonance energy transfer (FRET) from Tb3+ to merocyanine, resulting in reversible emission color switching. Notably, this process also induces coordination-enhanced circularly polarized luminescence (CPL) through supramolecular chirality amplification, a feature that distinguishes this system from conventional photochromic coordination assemblies. The resulting time-resolved multicolor optical switches exhibit tunable fading kinetics governed by the lanthanide-coordinated architecture. Leveraging these temporally programmable, multimodal optical responses that integrate modulation of apparent color, emission color, luminescence lifetime, and chiroptical signatures, we demonstrate sophisticated hierarchical information encryption with time-gated decryption and fully rewritable patterns. This work establishes a versatile coordination-driven assembly strategy for designing intelligent photonic materials whose chiroptical and emissive properties can be dynamically and precisely regulated by light.