A highly selective ratiometric fluorescent chemosensor for Hg~(2+) based on a new diarylethene with a stilbene-linked terpyridine unit

摘要

A novel asymmetrical diarylethene with a stilbene-linked terpyridine chromophore has been synthesized by Heck reaction. It exhibited effectively switchable fluorescence when triggered by UV/Vis and Hg~(2+)/EDTA. Induced by Hg~(2+), its emission peak was red-shifted by 60 nm and emission intensity was enhanced by 4-fold with a concomitant color change from light blue to bright green due to the formation of a 1:2 metal/ligand complex. As a result, the diarylethene can serve as a fluorescence chemosensor for highly selective recognition of Hg~(2+) in dichloromethane. Moreover, a complicated logic circuit was constructed with the unimolecular platform by using the fluorescence intensity at 514 nm as outputs and the combinational stimuli of light and chemical species as inputs.