Synthesis Of Anthraquinone Azo Benzene Deriatives And Its Anion Recognition

Anions exist widely in organisms, such as fluoride, iodine, anionic polyel-ectrolyte DNA, and so on, the transfermation across membranes and transmission of the anions in organisms are completed by combing with protein. Besides, anions play important roles in medicine, catalysis and environmental science, but we need use them scientifically. The phosphates which produced by excessive use of phosphorus fertilizers can result in the eutrophication of the rivers; The metabolites of nitrate can cause cancer. As a result, it is very important for us to do abundant research on the detection of anions, so the study of anion recognition system has become an extremely important area of research at present.Compounds that contain groups such as amides, thiourea, urea, pyrrole phenolic hydroxyl and so on, can be used as receptors for anions. Compound which concludes anthraquinone and azo is one of the ideal models for anion detection by naked eyes for its anthraquinone and azo as chormophoric groups. In view of the above, this dissertation designed and synthesized a range of anthraquinone azo benzene deriatives, studying their application in recognizing anions, the results were summarized as follows:1. The character of anions, its combining type with receptors and optical chemical sensor were briefly introduced; the research method of anion recognition was summarized.2. A pyrocatechol derivative bearing anthraquinone azo benzene was designed and synthesized as a receptor for anion recognition. The reactions between the receptor and the common anions at methyl cyanide solution were studied by UV-Vis spectrophotometry. It showed that the receptor could recognize F-and Ac-by naked eyes. We found that each receptor formed a complex in1:1binding model through the o-hydroxy of phenolic with F-or Ac-, and the spectra showed a remarkable red shift and the color of the solution turned from yellow to green with the addition of F, Ac-and H2PO4-, but the addition of the other anions did not disturb its identification to F-, Ac-and H2PO4-. The recognition mechanism was discussed preliminarily, it was found that the reason of the significant red shift of the absorption spectra was ascribed to the hydrogen bonds between host and anions, which promoted the intramolecular charge-transfer, resulting in a significant red shift of the absorption spectra, resulting in the obvious changing of the color of the solution.3. Three single hydroxyl azo anthraquinone derivatives, bearing o-hydroxyl of phenol as recognition site, azo group and anthraquinone group as signal group were designed and synthesized as receptors of anions. Their reactions with the common anions at DMSO and methyl cyanide solution with different dielectric constants were studied by UV-Vis spectrophotometer, and the mechanism of the reactions was further studied by Mir titration. The result indicated that the three receptors could recognize F and Ac by naked eyes. Receptors reacted with F-or Ac-through the o-hydroxyl of phenolic, which made obvious changes in both spectra and the color of the solutions. The addition of H2PO4-disturbed the identification lightly, the other anions did not influence the reactions between receptors and F-or Ac-. Methyl promotes the reactions between receptors and the anions. The polarity of the solvent had an effect on the reactions between receptors and anions. In DMSO and methyl cyanide solution with dirrerent dielectric constants, the receptors and F-or Ac-combined in two different ways.4. Two anthraquinone azo benzene derivatives which contain-NH2or-NHNH2were designed and synthesized to recognize anions. The interactions between receptors and common anions were studied by UV-Vis spectrophotometer in DMSO solution. It was found that the receptor containing-NH2could recognized F-selectively, and each receptor formed a complex in1:1binding model through the-NH2with F-in DMSO solution. The addition of F-gave rise to remarkable changes in both of the spectra and the color of the receptor, the spectra showed an obvious red shift and the color of the solution turned from yellow to green. Tiny dirrerence happened in the spectra and the color of the solution with the addition of Ac-, the spectra displayed lightly red shift and the color turned from yellow to yellow green, the other anions do not affect the action between receptor and F-. The receptor with-NHNH2could not distinguish different anions; the addition of the common anions did not make any difference in spectra or color of the solution. The recognition mechanism was studied preliminary.The acidity of the groups contacted with benzene have some effect with the recognition, the fact that the receptor with-NH2could recognize F but the receptor with-NHNH2could not react with F-is ascribed to the truth that acidity of-NH2is Stronger than that of-NHNH2.Compared to the other receptors, although the selectivity for F-of receptor5has been greatly improved, it is regrettable that receptor5could not react with F-only. We can design the proper structure of receptors and choose proper solutions in order to improve the selectivity for F-of receptors.