Highly Organized Spherical Hosts That Bind Organic Guests in Aqueous Solution with Micromolar Affinity: Microcalorimetry Studies
作者:Evgueni L. Piatnitski、Robert A. Flowers II、Kurt Deshayes
DOI:10.1002/(sici)1521-3765(20000317)6:6<999::aid-chem999>3.0.co;2-y
日期:2000.3.17
cavities of 11 A diameter that are soluble in aqueous solution were constructed. The binding of xylenes, aryl ethers, polyaromatic compounds, ferrocene derivatives, and bicyclic aliphatic compounds were examined by NMR spectroscopy and microcalorimetry. NMR binding studies indicated that binding depended upon guest hydrophobicity and shape. No binding was detected for guests in which a charge must
构造了两个新颖的,具有11 A直径球形空腔且可溶于水溶液的闭壳半癌状宿主。二甲苯,芳基醚,聚芳族化合物,二茂铁衍生物和双环脂族化合物的结合通过NMR光谱法和微量量热法进行了检查。NMR结合研究表明结合取决于客体疏水性和形状。未检测到必须将电荷作为内含物的一部分去溶剂化的客人或无法放入宿主腔内的客人的结合。分离出三种配合物2.萘,2。对二甲苯和2.二茂铁,发现它们在固相和水溶液中无限稳定。这些复合物的结合常数估计大于10(8)M-1。通过微量量热法测定了十三位客人,结合常数在10(7)和10(3)M-1之间。将此处获得的结果与以前对β-环糊精和环烷主体的研究结果进行比较,以及对熵-焓补偿数据的分析,表明与开壳宿主相比,该宿主结构的客体去溶剂化程度更高。这至少部分解释了与这些封闭壳宿主观察到的亲和力增加。用氢原子取代宿主门户中的羟基不会影响结合常数,这一发现与深埋在宿主腔体内的客体一致。据观察