Design And Synthesis Of Rhodamine Azo Fluorescent Probes

Rhodamine fluorescent dyes have a wide range of applications,due to its excellent photophyscial properties and unique structural characteristics.The azo compound has a property that the ultra-rapid conformational change around the-N=N-bond after photoexcitation which can cause fluorescence quenching of the adjacent fluorophore.Therefore,the azo derivative molecule of rhodamine does not fluoresce itself.The azo double bond is reduced and broken when a strong reducing substance is encountered.At that time,the rhodamine spiro ring is opened and the molecule recovers the rigid conjugated structure and produces color and fluorescence.In recent years,with the increasing performance requirements for fluorescent probes,the amino modification of the top-ring structure of rhodamine has attracted much attention.In this paper,based on the rhodamine 110/B,two kinds of rhodamine Azo derivatives were designed and synthesized by coupling reaction:rhodamine 110/B-phenol derivatives,rhodamine 110/B-aniline derivatives.The recognition performance of these derivatives was studied by UV-Vis absorption spectra and fluorescence emission spectra.The results showed that rhodamine azo fluorescent probes have selective response to hydrazine hydrate and pH,and can be used as corresponding identification probes.The main contents of the thesis are as follows:1.Rhodamine 110/B was prepared by reaction of m-aminophenol,phthalic anhydride and m-diethylaminophenol under certain conditions.Then,different aromatic compounds were selected for the coupling reaction to obtain rhodamine 110/B-phenol derivatives and rhodamine 110/B-aniline derivatives.Finally,these compounds were characterized by mass spectrometry,hydrogen spectroscopy and carbon spectroscopy.2.Azo double bond is a classic reducing agent reduction target.In this paper,the azo double bond is reduced and broken,and the recovery fluorescence of rhodamine probe is the basic principle.Under the conditions,the recognition performance of five kinds of probes on reducing substances was investigated by UV-Vis absorption spectra and fluorescence emission spectra.The results showed that the rhodamine azo probe has good selectivity for hydrazine hydrate recognition,but the polar protic solvent has a certain response to the probe.3.In this paper,UV-vis absorption and fluorescence emission spectroscopy studies showed that all five azo Rhodamine probes have good selectivity,linearity and metal ion competition to pH.