Coordinated Solvent Molecules Enable the Excellent Capabilities of Two Zn²⁺‐Based Complexes in Detecting l‐Arginine via Long‐Lived Luminescence Recovery

Abstract

Luminescence metal–organic materials (MOMs) are widely used as probes for detection. However, most of such probes are based on fluorescence and work in either turn‐off or turn‐on mode. In contrast, long‐lived (>10 ms) probes (LLPs) with recovery response to analyte are quite rare. Herein “solvation complex” strategy is used to prepare two new afterglow complexes with multiple coordinated solvents, trans‐complex 1 with both delayed fluorescence (DF) and room temperature phosphorescence (RTP), and cis‐complex 2 with RTP. Remarkably, they can serve as selective and recovery LLPs for l‐Arginine detection, with limit of detection down to 1.0 × 10−7 M. In addition, heating/fumigation can induce reversible arousal/silence of their afterglow, while H2O/DMSO vapor fumigation causes reversible crystalline‐to‐crystalline transformation between them. Detailed mechanism studies reveal that the change in coordinated solvent, including loss/acquisition, exchange, or replacement, plays a key role in such afterglow multi‐stimuli‐responsive properties. This work not only shows the potential of such long‐lived luminescence complex for recovery detection, but also reveals the unique advantages of solvation complex in the preparation of afterglow multi‐stimuli‐responsive materials