Solvent-Mediated Hydrogen Bond-driven Self-Assembly Materials for Dynamic Phosphorescence Emission

Organic room-temperature phosphorescence (RTP) materials with tunable emission intensity, lifetime, and quantum yield are vital for optoelectronics, bioimaging, and anti-counterfeiting. Herein, a facile strategy enables continuous RTP adjustment through hydrogen bonding-driven self-assembly of melamine (MA), cyanuric acid (CA), and 3,5-dicarboxyphenylboronic acid (IB, organic phosphor), mediated by protic (H 2O) and aprotic (DMSO) solvents. Interestingly, DMSO facilitates the formation of a disordered, low-crystallinity assembly (MC-IB 0) with weak RTP, while H 2O promotes the formation of an ordered, high-crystallinity framework (MC-IB 100) with strong RTP. Notably, increasing water content (from 0% to 100%) of the mixed solvent of H 2O and DMSO could continuously improves the crystallinity and RTP performance of the material, with phosphorescence lifetime extending from 0.81 s to 1.18 s and phosphorescence quantum yield rising from 1.73% to 11.93%. Solvent ultrasonic treatment enables the reversible switching between MC-IB 0 and MC-IB 100. The materials exhibit excellent performance in water content detection, pH sensing, and information storage. This work provides a simple pathway for dynamically responsive RTP materials, expanding their application scope.