Synthesis And Properties Of Fluorescent Probes Based On Heteroatom Bridged Calixarene

Fluorescent probe can specifically recognize a specific chemical substance and produce a fluorescence response signal.Fluorescent probe has the advantages of high sensitivity,high selectivity,simple and convenient real-time in-situ detection and visualization,it has become the preferred method for heavy metal and transition metal detection.Fluorescent probes have been increasingly valued by chemical researchers because of their significant application value.The heteroatom calixarene is characterized by the introduction of heteroatoms in the traditional cuparomatic bridged position instead of the original methylene,and the introduction of heteroatoms makes it have different conformational and identifying properties et al.compared with the classical calixarene.With its potential as a molecular platform and the ability to construct regulatory receptors,it has an important application prospect in the fields of ion transport,molecular devices,chemical sensing and molecular switching.This paper first summarizes the research status and the latest development of a series of heterocyclic fluorescent probes and heteroatom bridged calixarene fluorescent probes.On the basis of literature research,we developed the heteroatom calixarene as a structural platform introduced different fluorescent groups in its special alternate structure to construct novel fluorescent probe molecules that simultaneously recognize multiple different components,this paper mainly carried out the following aspects:1.(1)1,3-bis(amine ethyl)thiacalix[4]arene is reacted with an aldehyde-containing benzothiazole derivative to form a schiff type benzothiazole calixarene probe1;Then,the schiff base bond was reduced by sodium borohydride to obtain two kinds of thiapixel [4] arene fluorescence probes 2.(2)Coumarin aldehydes and naphthalene formaldehyde and 1,3-containing amine groups and 2,4-position quinoline-containing thiacalix[4]arene intermediates should be generated schiff base to obtain 1,3-coumarin-2,4-quinoline probe 3,1,3-naphthalene-2,4-quinoline probe 4;(3)The reaction of 4-chloro-7-nitrobenzo-2-oxa-1,3-oxadiazole(NBD-Cl)with isothiocyanate with the intermediate,wherein NBD-Cl is substituted by nucleophilic to give 1,3-NBD-2,4-quinoline probe 5,and the isothiocyanate reacts with the amine to form a urea structure and naphthalene-quinoline probe 6.(4)The structures of the synthesized intermediates and the final fluorescent probes were characterized by 1H NMR,13 C NMR,ESI-MS and IR.3.The characteristics of the different ion recognition properties of the probe were studied by UV absorption spectroscopy and fluorescence spectroscopy.(1)The results showed that benzothiazole fluorescence probe 1 can identify Zn2+ with high sensitivity and high selectivity,formed of fluorescent enhanced probe,issued bright yellow fluorescence,fluorescent color changes bright and have large stokes;(2)Zn2+,Mg2+,Cd2+ and F-can be highly sensitively and selectively identified by the coumarin-quinoline probe 3,added Zn2+,Mg2+,Cd2+fluorescence significantly enhanced at 460 nm,505nm,535 nm,through different emission wavelength and fluorescence color to distinguish three types of metal ions,F-maked fluorescence enhance at 465 nm,was a multi-target fluorescent probe;(3)The probe 5 can be used as a highly sensitive fluorescent probe for Ag+,Ag+ makes the probe 5 fluorescent redshift 35 nm to form the ratio fluorescence,the fluorescence color changes from yellow green to orange;the UV absorption spectrum is red shifted to 33 nm to form the ratio absorption,the solution changes from yellow to red.The 5-Ag+ system can be used to achieve an optical switch reversible process,and the 5-Ag+ system is a potential for I-detection of complex probe.