杂合受体设计成识别磺酸盐首基和全氟辛烷的氟尾部两者(CF 3(CF 2)7 SO 3 -,“PFOS”)通过偶合氟化羧酸在聚(氨基甲基)苯的支架制备。结合PFOS,CF 3 SO 3 - ,p -TsO -和Cl -通过监测1 H NMR和等温滴定量热法(ITC)。在氯仿溶剂中,氢键阴离子在酰胺N被伴随着低磁场位移ħ氟化受体的质子和热量的释放。1:1络合(K assoc)的缔合常数> 1000 M -1。类似的烃受体与阴离子客体的结合较弱(K assoc <50 M -1)。从头算计算表明,氟和非氟主体之间1:1结合强度的差异不能归因于N H供体酸度的差异。
杂合受体设计成识别磺酸盐首基和全氟辛烷的氟尾部两者(CF 3(CF 2)7 SO 3 -,“PFOS”)通过偶合氟化羧酸在聚(氨基甲基)苯的支架制备。结合PFOS,CF 3 SO 3 - ,p -TsO -和Cl -通过监测1 H NMR和等温滴定量热法(ITC)。在氯仿溶剂中,氢键阴离子在酰胺N被伴随着低磁场位移ħ氟化受体的质子和热量的释放。1:1络合(K assoc)的缔合常数> 1000 M -1。类似的烃受体与阴离子客体的结合较弱(K assoc <50 M -1)。从头算计算表明,氟和非氟主体之间1:1结合强度的差异不能归因于N H供体酸度的差异。
Hydrogen Bonding vs Steric Gearing in a Hexasubstituted Benzene
作者:Jesse V. Gavette、Andrew L. Sargent、William E. Allen
DOI:10.1021/jo800226s
日期:2008.5.1
Treatment of hexakis(bromomethyl)benzene with excess NaN3, followed by hydrogenation of the resultant polyazide, affords hexamine 3 in high yield. Coupling to six equivalents of nonanoic acid provides hexamide 5 without chromatographic purification. The NH resonance of 5 appears far downfield (∼9.7 ppm) in CDCl3 and is unaffected by changes in concentration or by addition of chloride or trifluoromethanesulfonate