Design, Synthesis And Properties Of Zn²⁺ Sensor Based On Diarylethene

Fluorescent chemosensor is widely used in biological and environmental detection of metal ions because of its simple operation and fast response.So far,a large number of Zn²⁺chemical sensors are widely reported due to its crucial role in the organism and the environment.Compared to the conventional chemical sensors for Zn²⁺with a single response,the multi-stimulus diarylethene sensors for Zn²⁺have gained a lot of interest.However,the study of Zn²⁺chemical sensors based on diarylethene with high selectivity and sensitivity still remains a great challenge.Based on the above ideas,this paper designed and synthesized seven kinds of novel asymmetrical diarylethene compound responsed to Zn²⁺.Their structures were characterized by NMR,IR,MS and elemental analysis.In this paper,the main contents are as follows:In chapter 1,the research process of the chemical sensors,diarylethene compound,the application of fluorescent chemical sensor based on diarylethene and the fluorescent chemosensor for recognition of Zn²⁺based on diarylethene were intensively introduced.In chapter 2,a novel diarylethene compound DT-1 with a di-2-picolylamine was designed,synthesized and the properties of its photochromic,fluorescent switch and Zn²⁺response have been systematically investigated.Inchapter3,aasymmetricdiaryletheneDT-2containing4-diethylaminosalicylaldehyde Schiff base unit was designed and synthesized.In methanol solution,DT-2 showed excellent photochromic property and remarkable fatigue resistance.The emission intensity of DT-2 notably increased with a color change from dark to blue,only Zn²⁺was applied among the various metal ions.This indicated that DT-2 could be served as a selective fluorescent sensor for Zn²⁺.Inchapter4,twodiarylethenederivativesDT-3⁴witha9-（4-aminophenyl）acridine unit were designed and synthesized and its multi-controllable switching behaviors induced by light and chemical stimuli were investigated.Upon irradiation with 297 nm UV light,the color of the solution changed from colorless to cyan in acetonitrile.DT-3 exhibited high selectivity for Zn²⁺.After addition of Zn²⁺,the color of the solution changed from colorless to yellow and the fluorescent color changed from red to bright yellow.The dramatic color change of the solution made‘naked-eye’detection of Zn²⁺ion possible.Taking advantage of the light and Zn²⁺ion stimuli（inputs）,and fluorescence intensity at 580nm（output）,a molecular logic gate was constructed.In chapter 5,three novel diarylethene compound DT-5⁷ with coumarin Shiff-base unit were designed and synthesized.In acetonitrile solution,DT-5⁷showed excellent photochromic property.Experimental results showed that pyrrole aromatic ring shifted their absorption band to a larger wavelength in the UV region upon photocyclization and isoxazole aromatic ring to shifted to shorter wavelength.DT-5 was not only has good selectivity for the Zn²⁺cation,but also to achieve the specific recognition of F^-anions.