LI-BONDING GATE( SELECTIVE ENCAPSULATION THROUGH THE INTRAMOLECULAR HYDROGEN)

We developed a self-organized monomeric molecular container 3 based on two pairs of intramolecular hydrogen bonds between adjacent carboxyli c acid moieties on the upper rim of the cavitand 1. The formation of t he molecular container was confirmed by inclusion phenomena of Li+ in a mixture of CDCl3 and C6D6. The lid formed by two pairs of intramolec ular hydrogen bonds can be opened in polar solvents such as CD3CN and the encapsulated guest was subsequently released. All these phenomena were elucidated by H-1 NMR spectroscopy, MALDI mass spectrometry, vapo r pressure osmometry, and molecular modelling studies. (C) 1997 Elsevi er Science Ltd.