A new diarylethene-derived probe for colorimetric sensing of Cu(II) and fluorometric sensing of Cu(II) and Zn(II): Photochromism and High Selectivity

Abstract

A novel photochromic diarylethene derivative containing a 2-(methylthio)benzenamine Schiff base (1O) unit was synthesized and its selective fluorometric/colorimetric sensing of multiple metal ions in methanol was demonstrated. The addition of Cu2+ enhanced the absorption of 1O up to 44 folds with the concomitant color change from colorless to yellow, which could be easily observed by the naked eye. In addition, 1O exhibited selective fluorescence responses to Cu2+ and Zn2+ with different fluorescence signals. Cu2+ quenched the fluorescence of 1O up to 98%, while Zn2+ enhanced the fluorescence of 1O by 53.8 folds, accompanied by the fluorescence color changes from light red to dark and bright yellow, respectively. Both coordination stoichiometries between 1O and Cu2+, and 1O and Zn2+ were determined to be 1:1. In all, diarylethene 1O can be potentially used as a chemosensor of both Cu2+ and Zn2+.