Synthesis And Study The Property Of Diarylethenes Based On Imidazole Structural Unit Molecule Sensors

Among all the photochromic materials,diarylethene compounds become most extensively studied one photo-chromic material due to their excellent thermal stability,significant fatigue resistance and light sensitivity.They can be potentially applied in photo-switches,optical memory,logic circuits,and chemical sensors and other fields.Currently,exploration and design of new structure,excellent properties of the photochromic compound have drawn people's attention.Scientists modulated diarylethene with new functional group to regulate its properties,which have been the main directions of research.Six kinds of diarylethenes molecule and were synthesized based on the above ideas.Their photochemical properties was investigated systematically,the main contents are as follows:In chapter 1,both the research background,progress of diarylethene compounds and the progress of imidazole-containing chemical sensor unit were reviewed.Their application in fluorescent switch and ion recognition were intensively introduced.Based on the survey of the current focus our research subject was brought out.In chapter 2,two novel diarylethene with a dithieno-beno-imidazole group were synthesized,and we discussed the difference of DTE-1 and DTE-2 in the optical properties,pH and ionic validity recognition performance.The emission intensity of diarylethene DTE-1 could be independently modulated by UV–vis light and pH.DTE-1 could be a promising candidate for the construction of a multi-state fluorescence switch.This compound could also serve as a fluorescence probe for the recognition of Al³⁺?Fe³⁺?Cr³⁺.In chapter 3,two novel photochromic diarylethene dimmers linked by a bis-thiophene-ethyl-imidazole group were synthesized.The photochromic properties and their multiple fluorescence switch induced by sequential stimulations with protons,light and ions of DTE-3 were investigated.It is noteworthy that DTE-3could construct a multiple switching system with reversible UV/vis irradiation,protonation/deprotonation and complexation/dissociation processes.DTE-3 could also serve as a fluorescence probe for the recognition of Al³⁺?Cr³⁺,which can be dissociated by EDTA.In chapter 4,two kinds of diarylethene with imidazole-containing pyridine,furan group were synthesized respectively.A systematic study of the DTE-5 and DTE-6photochromic properties,such as cyclization quantum yield,photo-conversion ratio,and fatigue resistance exhibited a strong correlation with its various substituted imidazole groups.