Inspired by allostery in nature, we synthesized cavitand
1 and investigated regulation of its conformational dynamics. Quantitative
1H NMRstudies have revealed that the rate of the conformational isomerization of
1 can be modulated using the external addition of acid. As
1maintains its vase-like conformation in an acidic environment, ample opportunities for controlling the kinetics of molecular recognition, andthus reactivity, in this and related receptors have arisen.