Macrocyclic receptor molecules with a pendant carboxylic acid group for the complexation of urea
作者:Veronika M. L. J. Aarts、Peter D. J. Grootenhuis、David N. Reinhoudt、Anna Czech、Bronislaw P. Czech、Richard A. Bartsch
DOI:10.1002/recl.19881070209
日期:——
5′-di-tert-butyl-3-(carboxymethyl)biphenyl crown ethers and several lariat ethers with pendant carboxylic acid groups, together with the determinations of the pKa values of these crown ether carboxylic acids, are described. In addition, the complexation of urea by these crown ethers has been investigated. Both the larger-ring biphenyl crown ethers (≥ 29 ring atoms) and lariat ethers (≥ 27 ring atoms) solubilized urea
5,5'-二叔丁基-3-(羧甲基)联苯冠醚和几种带有侧链羧酸基团的套索状醚的合成,以及p K a的测定描述了这些冠醚羧酸的值。另外,已经研究了这些冠醚与尿素的络合。大环联苯冠醚(≥29个环原子)和套索状醚(≥27个环原子)都将尿素溶解在氯仿中。套环醚使尿素络合的数据表明,为了有助于尿素络合,重要的是使羧酸基团靠近大环。当套索状醚的羧酸基团位于适当的位置时,尿素被这些大环配体的21–27%络合,联苯冠醚醚羧酸也是如此。这些结果表明,羧酸侧基可以帮助中性分子的络合。