Dicyanovinyl-substituted D-A type dithienylethenes: Synthesis, photochromism and colorimetric sensing for cyanide anion

摘要

A series of novel dithienylethene-based colorimetric sensors 1a-1d with a typical donor-acceptor structure have been successfully developed, which exhibited solvent-dependent photochromic properties in solution, as well as high selectivity and sensitivity for the naked-eye detection of cyanide anion in 95% aqueous CH3CN media. Moreover, it was found that different structures had a noteworthy effect on both their photochromic properties and colorimetric sensing for CN-. The sensing mechanism based on the nucleophilic addition reaction with CN- was confirmed by absorption spectral studies, H-1 NMR titration and DFT calculations. Among them, the sensor 1b displayed highly sensitive to CN- (35 s) and lower detection limit (0.25 mu M), which can be utilized as a potential colorimetric sensor for CN- in our daily life and environment.