SENSORS FOR ANIONS OF ENVIRONMENTAL AND BIOMEDICAL RELEVANCE

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 该项目涉及对环境和生物具有重要意义的阴离子受体的设计和合成。作为受体的多氮杂大环和氧阴离子和卤化物是第一年的焦点。在此期间，采用了三种方法：(I)受体的设计、合成和表征，(Ii)用核磁共振滴定技术检测合成的化合物与溶液中阴离子的结合能力，(Iii)研究主客体络合物的固态结构。合成了一种基于噻吩基的氮杂膦，并研究了其在固体和溶液中的阴离子结合性质。结晶学研究表明，该配体与桥头氨基质子的In-In构象结合了一个氯化物或三个硝酸盐。在氯络合物中，被包裹的阴离子位于空腔中，N+Cl3.10(1)；而对于硝酸盐络合物，三个阴离子位于三个侧袋中，并通过一个氧与两个In-In质子在顶端氮上桥联，平均距离N+O为3.238°。对氯化物、溴化物、碘化物、硝酸盐和硫酸盐进行了核磁共振滴定。结果表明，该配体能有效结合4,000~10,000 M~(-1)的阴离子。我们还合成了另外三个配体，用于研究溶液和固体中的阴离子。这些化合物目前正在由Clement G.Yedjou博士(该项目的合并者)进行研究，用于细胞毒性研究。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project involves the design and synthesis of receptors for anions of environmental and biological importance specifically. Polyazamacrocycles as receptors and oxoanions and halides were the focus during the first year. During this time, three approaches ware employed: (i) design, synthesis, and characterization of receptors, (ii) examination of the binding capabilities of the synthesized compounds for anions in solution by NMR titration technique, and (iii) investigation of solid state structures of the host-guest complexes. A thiophene based azacryptand has been synthesized, and its anion binding properties have been studied in both solid and solution states. Crystallographic studies indicate that the ligand binds one chloride or three nitrates with an in-in conformation of the bridgehead amino protons. In the chloride complex, the encapsulated anion sits in the cavity with N++++Cl¿ distance 3.10(1) ¿, whereas, for the nitrate complex, the three anions are located in three side pockets, and are bridged through one oxygen with the two in-in protons on the apical nitrogen with an average distance of N+++O of 3.238 ¿. The NMR titrations were performed for chloride, bromide, iodide, nitrate and sulfate. Results indicated that the ligand effectively binds these anions ranging from 4,000 to 100,000 M-1. Three other ligands were also synthesized that are planed to study for anions in both solution and solid states. These compounds are currently being investigated by Dr. Clement G. Yedjou (collobaroator of this project) for cytoxicity studies.