The Study Of Synthesis And Properties Of Diarylthene Based On Carbazole And Fluorene

The new molecular switch material is playing an increasingly important role in modern social life,From the molecular level,the molecular switch require a kand of dual-stable molecule,when it receives the excitation energy from external part,such as heating,light,electricity and so on,molecules could converte between this two states.Photochromism is the compound?A?which have isomerization reaction under irradiation with a certain wavelength can change to compound?B?,it can restore to the original state when it was heated or irradiated with another wavelength light.Photochromic compounds mainly include mainly fulgic anhydride,spirobi,azo,diarylethylene,and so on.Diarylthene compounds are of interest to many researchers because of their excellent thermal stability,excellent fatigue resistance and fast response time,it have a broad application prospect in the photon storage media and molecular devices and other fields.For now the main research direction of diarylthene is to modified the extremity of diarylthene to get new diarylthene with different function.Diarylthene with ion recognition function is particularly noticeable.In this work,five kinds of diarylthene were synthesised by connected carbazole and fluorene to diarylthene in the form of Schiff base,their structures were confirmed by single crystal X-ray diffraction analysis,NMR,IR and MS.The change of UV spectra,fluorescence spectra and solution color was recorded when this five kinds of diarylthene was regulated by light,acid,alkali,anion,and other stimulating effect in solution.The results show that,diarylthene compound DTE-1⁵ have good photochromic and fluorescent properties in the methanol solution,DTE-1 and DTE-2 have responds to ions.DTE-1 have respond to Sn²⁺and Cu²⁺and can served as a naked-eye fluorescent chemsensor.The absorption of spectrum of DTE-3 could be modulated by light,CO₃^2-,and acid/base in methanol,DTE-3 could be served as a naked-eye fluorescent chemsensor for CO₃^2-.What's more,the the absorption of spectrum of DTE-3 could be modulated by CN^-in THF,too.The color of the solution of DTE-3 changed obviously when CN^-was added in,it aslo could be served as a naked-eye fluorescent chemsensor for CN^-.Two new diarylethene derivatives DTE-4 and DTE-5 were synthesized and their structure were determined by single crystal X-ray diffraction analysis.Photochromic of DTE-4 and DTE-5 is excellenct.Due to the introduction of benzene ring,compared to DTE-4,DTE-5 have longer UV absorption wavelengths and fluorescence emission wavelengths,better thermal stability and better resistance to fatigue.It can be seen that the increase of conjugate would improve the thermal stability and fatigue resistance for diarylethene.Moreover,DTE-1,DTE-2 and DTE-3 can be applied to dected ions and anions in nature with high accuracy.