Dynamically Reconfigurable Ir(III) Complex-Based Co-Assemblies for Sequential Energy Transfer and Programmable Luminescence.

Most artificial light-harvesting systems (ALHSs) are built from predefined donor-acceptor combinations, making their energy transfer and emission difficult to alter after assembly. Combining reversible reconfiguration with efficient sequential energy transfer remains challenging. Herein, we report reconfigurable Ir(III) complex-based co-assemblies for sequential energy transfer and programmable luminescence. In H2O/CH3CN with a 90% water content, Ir-D self-assembles into blue-phosphorescent nanorods. Co-assembly of Ir-D with erythrosine Y (A1) or Nile red (A2) enables one-step energy transfer, whereas co-assembly with both acceptors enables two-step sequential energy transfer with 84.8% efficiency and 88.7% photoluminescence quantum yield. Notably, only 0.1 mol% A2 affords white-light emission with CIE coordinates of (0.31, 0.34), reflecting efficient acceptor-emission amplification. Beyond composition-dependent tuning, the donor-acceptor co-assemblies can be reconstructed after formation: heating dissociates the assemblies, and adding or adjusting A1 and A2 in the dissociated state produces new co-assemblies upon cooling, changing the emission from white to yellow and then red. The thermally controlled switching of energy transfer is further used for multicolor information encryption and molecular logic operations. This work shows that supramolecular dynamics can move ALHSs beyond static donor-acceptor construction by allowing energy transfer and luminescence to be reconfigured after co-assembly.