A tricolor-switchable stimuli-responsive luminescent binuclear Cu() complex with switchable NH O interactions

Color regulation of solid-state luminescence is desirable and challenging. We report herein a new 1,2,4-triazole-based bimetallic cuprous complex exhibiting blue-green-yellow tricolor luminescence conversion and thermally activated delayed fluorescence, and the origin and possible application of this tricolor luminescence conversion are also studied. It is shown that blue-green bicolor luminescence conversion is ascribed to the loss and recovery of CH 2 Cl 2 solvent molecules, as supported by the CH 2 Cl 2 -filled pore channel structure present in the crystal lattice revealed by single-crystal structural analysis and the variation of CH 2 Cl 2 signal in the 1 H NMR spectra. Green-yellow bicolor luminescence conversion is attributed to the destruction and restoration of the packing mode caused by the breaking and rebuilding of NH O hydrogen bonds under grinding and CH 2 Cl 2 vapor, as confirmed by PXRD and FT-IR analyses in various solid states. Blue-green-yellow tricolor luminescence conversion is attributed to the loss and recovery of CH 2 Cl 2 solvent molecules and the destruction and restoration of the orderly packing array caused by the breaking and rebuilding of NH O hydrogen bonds.