Persistent Room‐Temperature Phosphorescent Triazole Derivatives with High Quantum Yields and Long Lifetimes

Abstract

Pure organic persistent room‐temperature phosphorescence (p‐RTP) materials have attracted rapidly growing attention due to their unique photophysical properties and wide potential practical applications. However, most of the reported pure organic p‐RTP materials have low quantum yields and short lifetimes, and many p‐RTP compounds contain large π‐conjugated structures, which are difficult and complex to synthesize. Herein, a series of triazole derivatives with efficient p‐RTP emissions is reported. 2H‐1,2,3‐triazole‐4,5‐dicarboxylic acid (TDAc) is first found to exhibit green RTP under 312 nm excitation. Then, a series of ionized products of TDAc and their isomers with red‐shifted RTP emissions are further obtained by ionization of TDAc. Among them, the sodium 2H‐1,2,3‐triazole‐4‐carboxy‐5‐carboxylate can emit RTP with an ultra‐long phosphorescence lifetime (3.25 s) and high photoluminescence (PL) and p‐RTP quantum yields of 31.3% and 14.2%, respectively, as well as mechanorochromic behavior. Experimental results and theoretical calculations prove that strong intra‐/intermolecular interactions including hydrogen bonding and ionic bonding promote the overlap of molecular orbitals to form effective through‐space conjugation (TSC) and greatly stabilize the conformations, thus achieving efficient p‐RTP emissions. This work provides a simple and efficient strategy for designing p‐RTP compounds with high quantum yields.

Achieving time-dependent and color-tunable ultralong room temperature phosphorescence through sodiation reconfiguration for dynamic 5D information encryption

“…quantum efficiency because a long lifetime means a slow excited-state conversion and decay. 29 Compared with common RTP materials (Table S1, ESI†), the prepared Al/Phe-PMs not only have an ultralong lifetime (1015.3 ms), but also have a good phos. quantum efficiency (7.98%).…”