A macrobicyclic receptor with versatile recognition properties: Simultaneous binding of an ion pair and selective complexation of dimethylsulfoxide
A macrobicyclic receptor with versatile recognition properties: Simultaneous binding of an ion pair and selective complexation of dimethylsulfoxide
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DOI：
10.1021/ja994487r
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发表时间：
2000-07-05
影响因子：
15
通讯作者：
Smith, BD
中科院分区：
文献类型：
--
作者：
Deetz, MJ;Shang, M;Smith, BD
合成了双环受体，并评价了其在有机溶剂中结合碱金属卤化物盐和极性中性分子的能力。受体设计相对简单，因为它是二苯并-18-冠-6和桥接1，3-苯基二甲酰胺的组合。在1摩尔当量的金属阳离子的存在下，氯化物亲和力按以下顺序增强：K+（9倍增强）> Na+（8倍增强）远大于Cs+（无增强）。X射线晶体结构显示，受体结合氯化钠作为溶剂共享离子对。在氯仿溶剂中，该受体对乙腈、硝基甲烷和丙酮的亲和力很弱，而对二甲亚砜的结合常数在295 K时为160 M-1。X射线晶体结构表明，二甲基亚砜深深地结合在受体空腔中，并通过桥接水分子与受体形成氢键。还有证据表明CH-O相互作用。固-液萃取研究表明，受体可以溶解并与尿素，伯酰胺，和伯磺酰胺在CDCl 3，但不溶解氨基酸。
A bicyclic receptor was synthesized and evaluated for its ability to bind alkali halide salts and polar neutral molecules in organic solvents. The receptor design is relatively straightforward in the sense that it is a combination of a dibenzo-18-crown-6 and a bridging 1,3-phenyldicarboxamide. In the presence of 1 mol equiv of metal cation, chloride affinities are enhanced in the order: K+ (9-fold enhancement) > Na+ (8-fold enhancement) much greater than Cs+ (no enhancement). An X-ray crystal structure shows that the receptor binds sodium chloride as a solvent-shared ion pair. The receptor has very weak affinity for acetonitrile, nitromethane, or acetone in chloroform solvent, whereas the association constant for dimethylsulfoxide is 160 M-1 at 295 K. An X-ray crystal structure shows that the dimethylsulfoxide is bound deeply in the receptor cavity and forms hydrogens bonds to the receptor via a bridging water molecule. There is also evidence for CH-O interactions. Solid-liquid extraction studies show that the receptor can dissolve and associate with urea, primary amides, and primary sulfonamides in CDCl3 but does not dissolve amino acids.