GATING AS A CONTROL ELEMENT IN CONSTRICTIVE BINDING AND GUEST RELEASEBY HEMICARCERANDS

Theoretical modeling of the dynamics of complexation and decomplexatio n of guest molecules by container molecules reveals that gating has a critical influence on the ease of formation and stability of host-gues t complexes. Hosts equipped with gates can form very stable complexes with a variety of guests under readily achievable conditions. Gating i nvolves conformational processes of the host molecule that alter the s ize of the portals through which guest molecules pass. ''French door'' and ''sliding door'' mechanisms of gate opening are identified.