1,10-邻菲啰啉并咪唑衍生物阴离子受体的合成及识别性能

设计合成了2个1,10-邻菲啰啉并咪唑衍生物阴离子受体2-(2-羟基苯基)-1H-咪唑4,5-f]1,10]邻菲啰啉(1)和2-(2-羟基-5-溴苯基)-1H-咪唑4,5-f]1,10]邻菲啰啉(2), 受体2的结构由X射线单晶衍射分析确证. 通过紫外-可见光谱滴定及 ¹H NMR滴定研究了这2个受体对F^-, Cl^-, Br^-, I^-, H₂PO₄^-和AcO^- 6种阴离子的识别传感作用及作用机理. 结果表明, 受体对AcO^-, F^-和H₂PO₄^-有较强的传感作用, 溶液颜色由淡黄色变为黄色; 对Cl^-的作用较弱; 而对Br^-和I^-则无明显作用. 通过机理研究发现, 受体与F^-, H₂PO₄^-和AcO^-形成1: 1的氢键超分子, 当阴离子的量超过受体的1倍以后, 咪唑氮上的氢转移到阴离子; 受体与Cl^-以氢键形成超分子复合物, 而与Br^-和I^-作用很弱.

Synthesis of Two Anion Receptors of 1H-Imidazo [4,5-f][1,10] phenanthroline Derivatives and Their Recognition Properties

Anion play important roles in a wide range of chemical,biological and environmental processes.So anion binding and sensing became an active research field in supramolecular chemistry with potential applications in biomedical and environmental monitoring,anion exchange as well as anion transport.Artificial neutral receptors for anions are designed and synthesized in which color metric sensors are paid a good deal of attention for they could efficiently change their photo physical properties in the presence of anions.Imidazole and phenol are recently used in the design of neutral receptors for anions due to their ability to act as H-bond donors.Two anion receptors of 1H-imidazo4,5-f]1,10]phenanthroline derivatives,2-(2-hydroxyphenyl)-1H-imidazo4,5-f]1,10]phenan-throline(1) and 2-(2-hydroxy-5-bromophenyl)-1H-imidazo4,5-f]1,10]phenanthroline(2) were designed and synthesized,and the structure of compound 2 was confirmed by single crystal X-ray diffraction analysis.Anion sensing and the mechanism studies were carried out by UV-Vis spectrophotometric titration and 1H NMR titration.The receptors exhibited sensing towards CH3COO-,F-and H2PO-4 with color of the solution changed from pale yellow to yellow,and weakly sensing towards Cl-with inconspicuous response towards Br-and I-in DMSO.The receptors formed hydrogen bond supramolecular with anions F-,H2PO-4 and CH3COO-as 1∶1 withinreceptor]/=1.As flowed with the molar ratio exceeded 1,the proton of 1H-imidazo deprotoned and linked with the anion.The receptors formed hydrogen bond supramolecular with Cl-.