Coordination Mode Engineering of Silver Cages: From ACQ to AIE for Sequential Artificial Light Harvesting and Near-White Light Emission

High Resolution Image Download MS PowerPoint Slide Silver(I)-based metallacages are gaining interest in supramolecular chemistry owing to their tunable properties and diverse applications. Herein, we report a sequential artificial light-harvesting system using a silver-based cage. Two metallacages were synthesized: one coordinated through nitrogen ( MC 1, N–Ag–N) and the other through carbene carbon ( MC 2, C–Ag–C), each with newly constructed aggregation-induced emissive (AIE-active) ligands. MC 1 presents a flexible structure and exhibits AIE properties in the aggregate form, allowing for efficient three-stage sequential energy transfer from the cage ( MC 1 ) to eosin-Y (ESY), to sulforhodamine 101 (SR101), and finally to Cyanine-5-maleimide (Cy5). Notably, we can easily achieve bright white-light emission with a high quantum yield of 93%. In sharp contrast, MC 2 with a rigid structure exhibits high fluorescence in the solution state, while significant fluorescence quenching occurs in its aggregated state, thereby prohibiting its application in light-harvesting systems. This work focuses on the crucial function of structural flexibility in silver-based metallacages in energy-transfer processes and promotes silver-based metallacages as promising new candidates for advanced sequential artificial light-harvesting.