Recognition of Achiral and Chiral Ammonium Salts by Neutral Ditopic Receptors Based on Chiral Salen-UO<sub>2</sub> Macrocycles
作者:Maria E. Amato、Francesco P. Ballistreri、Salvatore Gentile、Andrea Pappalardo、Gaetano A. Tomaselli、Rosa M. Toscano
DOI:10.1021/jo902328y
日期:2010.3.5
A mononuclear (M20) and a dinuclear (M40) uranyl chiral macrocyclic complex, incorporating both a salen unit containing two phenyl rings linked to a chiral diimine bridge and the (R)-BINOL unit, behaves as an efficient ditopic receptor for achiral and chiral quaternary ammonium salts. Binding affinities in chloroform solution have been measured for 1:1 complexes of many quaternary salts encompassing
单核(M20)和双核(M40)铀酰手性大环配合物,包含含有两个与手性二亚胺桥连接的苯环的salen单元和(R)-BINOL单元可作为非手性和手性季铵盐的有效位位受体。已测量氯仿溶液中许多季盐的1:1配合物的结合亲和力,包括四甲基铵(TMA),四乙基铵(TEA),四丁基铵(TBA)和乙酰胆碱(ACh)以及三甲基苯胺(TriMAn),苄基三甲基铵(BnTriMA ),(α-甲基苄基)三甲基铵和吡咯烷鎓阳离子。所述盐的阴离子是由硬路易斯酸性铀酰位点结合,随着增加的结合效率上增加了阴离子硬度(I - <溴- <氯-),而联萘基部分或水杨醛单元或二亚胺桥的苯环的CH-π或π-π引力可确保识别阳离子配偶体。通过MM计算获得的受体-阴离子-阳离子三元配合物的优化结构得到2D-ROESY NMR测量的支持。