Enabling Dual Phosphorescence by Locating a Flexible Ligand in Zn-Based Hybrid Frameworks

Room-temperature phosphorescence (RTP) materials with recognizable afterglow property have gained widespread attraction. Multicolor RTP has added benefits in multiplexed biological labeling, a zero background ratiometric sensor, a multicolor display, and other fields. However, it is a great challenge to prepare multicolor RTP from a single-component compound according to Kasha’s rule. Herein, we propose a strategy to design multicolor RTP in a metal–organic hybrid framework through constructing chromophores in both isolated state and dimer state using a flexible tetradentate ligand. Two compounds were synthesized that presented blue and green dual phosphorescence with different lifetimes at ambient conditions. The photoluminescence mechanism has been thoroughly studied by structure–property analysis. This study provides various possibilities to prepare high-performing RTP materials by the rational design and synthesis of similar compounds.