The Study Of Synthesis And Properties Of Diarylthene Fluorescence Sensors Based On Schiffe Bases Or Quinolines

The compounds which under irradiation with UV and visible light alternativly can change between its one isomer and the other isomer called diarylethenes compounds.Among all photochromic compounds,organic diarylethenes were regarded as one of the most attractive candidates for practical applications owing to their excellent thermal stability,remarkable fatigue resistance,high sensitivity,and rapid response.So far,diarylethenes with versatile functional groups have been widely applied as fluorescent probes in cell imaging.To date,various functional units have been successfully incorporated into diarylethenes,and most of them could serve as chemosensors for various metal ions.Recently,the fluorescent method has become popular dueto its operational simplicity,high selectivity and sensitivity,real-time response and naked eye detection.Six kinds of diarylthene compounds were designed and synthesized by introducing thiocarbamide,antipyrine or quinoline and their structures were confirmed by single crystal X-ray diffraction analysis,NMR,IR and MS.Their fluorescent and absorbent switching characteristics induced by base/acid,light,as well as metal ions were systematically investigated.The results showed that diarylthene compounds DT-1?6 showed favorable photochromism by photoirradiation in acetonitrile.The fluorescent and absorbent spectra of DT-1?2 can be modulated by acid/base.However,the fluorescent and absorbent spectra of DT-2 can be modulated by Zn²⁺,while DT-1 can't.Moreover,DT-2 was highly selective toward Zn²⁺ion with obvious fluorescence change from light blue to bright yellow in acetonitrile and can serve as a naked-eye fluorescent chemsensor.The multi-controllable photochromic and fluorescent behaviors of diarylthene compounds DT-3?4 induced by stimulation of light,acid/base,and metal ions were investigated in detail.The results showed that both of them can be regarded as fluorescent chemsensors for Al³⁺.Compared with DT-4,DT-3 exhibited longer absorbent wavelength,stronger fluorescent emission intensity and more selective for Al³⁺,this may becsuse of the introduction of benzene.Two new diarylethene derivatives DT-5?6 were synthesized and their structures were determined by single crystal X-ray diffraction analysis.Properties of DT-5such as photochromism,fluorescent switches and detection for metal ions were measured.The results indicated that the DT-5c was highly selective toward Cu²⁺with an obvious absorption decrease and color change from blue to colorless,even in the presence of other metal ions.The binding constant for 1c and Cu²⁺was 2.0×10⁴mol L^-1and the limit of detection for Cu²⁺was calculated to be lower than that in drink water.Compared with DT-6,DT-5 exhibited longer absorbent wavelength,fluorescent emission wavelength,better fatigue resistance and bigger fluorescence modulation efficiency due to the introduction of benzene.Furthermore,various logic circuits were constructed according to the multi-controllable photochromic and fluorescentbehaviors of diarylthene compounds DT-2,DT-3 and DT-5.