肯普氏三酸衍生物与二氨基间苯二甲烯的缩合反应产生了空洞,空洞具有迄今为止制备的最深的腔,其特征是向内的羧酸。带有酸的延伸的6,7-二氨基喹喔啉壁允许容纳大的胺,例如1-金刚烷甲胺,以及较小的胺,例如三乙胺。金刚烷基和环己基异氰酸酯也以将异腈官能团定位在羧酸基团附近的方式结合在深腔体中。反应在环境温度下在腔体内发生,以形成相应的N-酰基甲酰胺。通过(1)1 H NMR和IR光谱法检测到低浓度的瞬时O-酰基异酰胺中间体。
Deep cavitands having three fixed walls and one mobile wall were prepared. The longer wall, built from a quinoxaline spacer, showed enhanced NMR spectra of guests, but the shorter wall based on a benzene spacer showed tighter binding and slower exchange of guests.