Achieving Long‐Lived Visible‐Light‐Excited Phosphorescence Through Orchestrating Charge Transfer in Terpyridine‐Based Donor–Acceptor Fluorophores

Abstract Long‐lived luminescent materials have garnered considerable attention due to their fascinating self‐sustained afterglow emission and promising applications. However, most afterglow materials remain constrained to high‐energy excitation, inducing accelerated photodegradation and posing biosafety risks through mutagenic effects. Herein, the study presents a molecular engineering paradigm in low‐energy excitation to realize long‐lived visible‐light‐excitable phosphorescence (VEP) via controllably modulating charge transfer (CT) processes in donor‐acceptor (D‐A) designed fluorophores. By anchoring electron‐donating triphenylamine (TPA) to a π‐accepting terpyridine (Tpy) unit, the D‐A engineered fluorophores serve as versatile platforms for introducing dynamic Zn(II)‐Tpy coordination and sequential protonation to largely enhance CT for bathochromic absorption shift, thereby enabling tunable and multicolor VEP. Furthermore, the photo‐oxidation process induces structural evolutions of fluorophores to modulate intramolecular CT (ICT), resulting in ultralong VEP lasting more than 3 s (artificial sunlight excitation) and 1 s (low‐power LED) under ambient conditions. Encouraged by the tunable properties of these versatile VEP materials, time‐gated anti‐counterfeiting and multi‐level encryption are demonstrated with a high security level. This work establishes an effective toolbox for designing and fabricating VEP materials through precise CT engineering, advancing their adaptability for next‐generation photonic technologies.