Dual binding mode of alkylammonium cations to (1,3)-calix[5]crown-6 triesters
作者:Mario Gattuso、Anna Notti、Sebastiano Pappalardo、Melchiorre F Parisi
DOI:10.1016/s0040-4039(98)00107-5
日期:1998.4
Potentially heteroditopic receptors 1c-h are easily obtained by exhaustivealkylation of (1,3)-calix[5]crown-6 triols 1a () or 1b (R′ = H) with alkyl bromoacetates. 1H NMR titration experiments provide clear evidence for a dual (endo-cavity and/or exo-cavity) binding mode of alkylammonium cations to hosts 1c-h, depending on the shape of the guest and the size of substituents at the upper rim.
通过将(1,3)-calix [5] crown-6三醇1a()或1b(R'= H)与溴代乙酸烷基酯进行完全烷基化反应,可以轻松获得潜在的异位受体1c-h。1个1 H NMR滴定实验提供明确的证据用于双(内切-cavity和/或外切-cavity)结合烷基铵阳离子的模式给主机1C-H ,这取决于客户的形状和取代基中的上边缘的大小。