Coordination‐Induced Structural Rigidity for Achieving Ultralong‐Lived Aqueous Room Temperature Phosphorescence

• Published in: Advanced optical materials 2024-12, Vol.12 (34), p.n/a
• Main Authors: Liang, Li Ya, Gao, Ya Ting, Chang, Shuai, Lv, Jian, Wang, Lu, Liu, Meng Li, Wu, Da Jun, Ye, Ming Jie, Chen, Bin Bin, Li, Da Wei
• Format: Article
• Language: English
• Subjects: anions recognition; Aqueous environments; aqueous room‐temperature phosphorescence; Aqueous solutions; Bonding agents; Chemical bonds; Coordination; coordination‐induced structural rigidity; Deoxygenation; Functional groups; Hydrogen bonding; Hydrophilicity; Inorganic salts; Magnesium; metal‐organic coordination; Moisture content; Phosphorescence; Rigidity; Room temperature; Visual effects; Water chemistry
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202401642

Designing ultralong‐lived aqueous room temperature phosphorescence (RTP) materials has become an actively pursued but challenging research area. Herein, a coordination‐induced structural rigidity (CISR) strategy is proposed to achieve ultralong RTP lifetime in magnesium/pyromellitic acid phosphorescent materials (Mg/PMA‐PMs) with abundant Mg2+ ions sites and hydrophilic groups in aqueous solution. Compared to their dry state (448.77 ms), the lifetime of Mg/PMA‐PMs significantly increases to 1026.17 ms with the addition of a small amount of water (50 wt%). Even in a fully non‐deoxygenated aqueous environment (above 200 wt% water), where Mg/PMA‐PMs disintegrate to form a nanosuspension, they still exhibit an ultralong aqueous RTP lifetime of ≈800 ms. The water‐enhanced RTP properties are attributed to water molecules coordinating with Mg2+ ions and acting as bridging agents to bind with hydrophilic groups through hydrogen bonding. This interaction rigidifies functional groups and inhibits their motions, leading to a substantial reduction in nonradiative decay. Furthermore, the CISR mechanism effectively explains the RTP enhancement effect of water on inorganic salt phosphorescent systems. This work not only provides a new approach for constructing efficient aqueous RTP materials, but also develops a powerful tool for visual anion recognition. In this work, magnesium/pyromellitic acid phosphorescent materials (Mg/PMA‐PMs) with abundant Mg2+ ions sites and hydrophilic groups are prepared. The Mg/PMA‐PMs show an ultralong aqueous RTP lifetime, which is proven to be attributed to the unique coordination‐induced structural rigidity mechanism. Because of the coordination‐regulated RTP properties, the Mg/PMA‐PMs can be used for visual anions recognition in aqueous solutions.