A ratiometric fluorescent chemodosimeter based on a hydrolysis reaction for the superwide continuous range detection of water in MeOH, MeCN, and DMF

In this work, a novel Schiff base chemodosimeter ( 2 ) based on salicylaldehyde containing a cyano group ( 1 ) and trometamol was designed and synthesized, which has a large Stokes shift (>100 nm) and remarkable solvatochromism. Compound 2 could be utilized as a sensitive fluorescent probe that quantitatively detects the water content in MeOH, MeCN, and DMF in a superwide continuous range and with a low detection limit, accompanied by a fluorescence color change from blue to green. The response range was 0–80% v/v for MeOH, 0–98% v/v for MeCN, and 0–90% v/v for DMF, and the detection limits were 0.0621% v/v (MeOH), 0.0327% v/v (MeCN) and 0.0910% v/v (DMF), respectively. Meanwhile, UV–Vis, IR, 1 H NMR, and MS characterization methods were used to investigate the mechanism. The results showed that water induced the breaking of the C N bond of 2 and the structural transition between alcohol and ketone of 1 . In addition, 2 was successfully loaded onto the test paper for the detection of water in the solid phase.