Study On Design, Synthesis And Anion Recognition Properties Of Salicylic Acid Oriented N-substituted Receptors

Anion sensing is an important research field of supramolecular chemisty because anions play a very important effect in biology, medicine, chemical and environmental. Due to the limitations of the characteristics of anions, the critical factor for anion sensing is how to design and synthesis receptors. Since hydrogen-bond can provide multiple binding sites, so amide, urea and thiourea groups which can provide a stronger hydrogen-bond donor ability and less affected by pH values, have attract a great interest in supramolecular chemistry and have been widely used for design and synthesis novel anions sensing receptors. What is more, salicylic acid is an important intermediate in organic synthesis, with a wide range of biological activity and an important physiological effect. In view of above, this paper designed and synthesized a series of novel salicylic acid oriented amide and thiourea derivatives, the binding properties of these receptors with anions were studied by UV-vis spectroscopy methods. The major research contents are as follows:1. Researches in the development of anions sensing were briefly reviewed on the following contents:(Ⅰ) the significance of anion recognition;(Ⅱ) the structural characters of anions;(Ⅲ) the type and research development of anions sensors;(IV) the research methods for anion recognition.2. A novel salicylic acid oriented amide receptor L1was designed and synthesized, the binding properties of L1with anions was examined by UV-vis in DMSO and CH3CN.3. A series novel salicylic acid oriented acylthiourea receptors5a-5m were designed and synthesized, and the binding properties of5a-5m with anions, such as F", Cl-, Br-, I-, HSO4-, CIO4-, AcO-were examined by UV-vis in DMSO. The results showed that these anions have selective recognition ability towards F-and AcO-better than the other five kinds of anions. A clear color change was observed from light yellow to yellow with the addition of F" and AcO-to the DMSO solution of these receptors. Solvation (Protic solvent) effect and the data of Job-plot confirmed a1:1complex was formed between receptors and these two anions through hydrogen-bond.4. A series novel salicylic acid oriented acylthiosemicarbazides derivatives AR1-AR4were designed and synthesized, and the binding properties of AR-AR4with F-, Cl-, Br-, I-, HSO4-, ClO4-, AcO-were examined by UV-vis in DMSO and DMSO-5%H2O. The results indicated that receptor AR4has a better sensing ability with F-and AcO-by clear color changes from light yellow to yellow, while AR1-AR3can not recognize these seven anions effectively. The data of Job-plot and solvation effect confirmed a1:1complex was formed between AR4and these two anions through hydrogen-bond.