Study On Synthesis Of Anion Fluorescent Sensors And Their Recognition Properties In Aqueous Media

Most of anions exist in the biosystem. The study of anions recognition has attracted attentionwidely, in order to understand the biocatalytic process in biological systems. As the special form of theanions, chiral anions role in many chemical and biological processes. The recognition and sensing of chiralsubstrates by synthetic receptive molecular systems have continued to attract much attention because of thefundamental of them. The study of anions recognition is not only playing an important role insupramolecular, but also existing vital to the development of pharmaceutical, biomedical, material scienceand so on. Because many important biological anions exist in the aqueous solution, the design, synthesisand study of high selective chemistry sensor, especially water soluble sensor are in harmony with modemculture.The chiral “clamp” and “chain” host molecules, which bridging with nitrogen atom or oxygenatom, have the adjustable size, and can form hydrogen bond with some anions easily. So they cause moreresearchers to attract much attention. To introduction of a chiral center and fluorophore in the neutral hostmolecule, and use the different of photochemical response, we can realize the chiral recognition accuratelyand effectively.In this thesis, for the recognition of anions, a series of novel artificial fluorescent chemicalsensors were designed and synthesized based on acridine, phenanthroline or anthracene, and confirmed thecorrectness of their structures. Their binging properties to the series of common anions (chiral carboxylatesand biological important anions) were evaluated by UV-vis, fluorescence emission,1HNMR, MS andsimulation methods. The thesis is divided into four chapters, and the main contents are as follows:(1) Describes the mechanism of the anion sensing and various types of anion receptors. Reviewthe research progress of fluorescent and colorimetric anion receptors and their recognition abilities to anionguests.(2) Through introduce the chial amino acid methyl ester, acridine and signal units, novel chiralreceptors S-1, S-2, S-3and R-1were synthesized. And studied their selectively recognition ability forisomers of malic acid by fluorescence spectroscopy, mass spectrometry in aqueous solution. Sensor S-1was found to present good enantioselective fluorescent sensing ability to malate anion. The resultsindicated that sensor S-1was very promising to be used as a fluorescent sensor in determining malate anion in H2O solution. The changes of color can be observated directly by naked eye.(3) The compounds L1, L2and D1based on phenanthroline Schiff base bearing chiral alkaminegroups have been synthesized and demonstrated. The sensing ability of the compounds in the presence ofmetal cations was studied by UV-vis and fluorescent spectroscopy. The experimental results indicate thatcompounds L1and D1could act as selective fluorescent sensors for for the Eu3+ion with fluorescencequenching in aqueous solution. Additionally, the emission properties of the L1-Eu3+complex can beapplied as enantioselective sensor to distinguish malate anion from other carboxylate anions in an aqueoussolvent. And can be seen color change with the naked eye.(4) Five compounds were synthesized based anthracene L0, L1, L2, L3and L4. The selectiveability to common anions was studied through UV absorption spectroscopy, fluorescence spectroscopytitration, HRMS and1H NMR in aqueous solution. The results showed that the sensors of L2and AcO-have good recognition results, and L2formed the1∶1shoichiometriy complex with AcO-through themultiple hydrogen bonding interactions. With L2-Ag+as a new fluorescent sensor, which had a goodrecognition effect for I-, and the color change was obviously. This showed that the sensor L2with AcO-and L2-Ag+with I-had very good selective recognition capabilities.