A novel diarylethene-based fluorescent "turn-on" sensor for the selective detection of Mg²

A new photochromic diarylethene derivative with a 4-methylphenol unit has been designed and synthesized. It displayed distinct photochromism and fluorescent ''turn on'' features to Mg²⁺ in acetonitrile solution. With the addition of Mg²⁺, there was an obvious increase of fluorescent emission intensity at 552 nm, accompanied by a clear change of fluorescent color from dark purple to green. Meantime, the 1 : 1 stoichiometry between the derivative and Mg²⁺ was verified by Job's plot and HRMS. Furthermore, the sensor was successfully applied in the detection of Mg²⁺ in practical samples. Moreover, based on the multiple-responsive fluorescence switching behaviors, it also could be used to construct a molecular logic circuit with UV/vis lights and Mg²⁺/EDTA as input signals and the emission at 552 nm as the output signal.