A Molecular Lock and Key: “Unlocked–Locked” Conformational Switching of a Receptor by Anions

Abstract

Lock up your valuables: Receptor 1 acts as a “molecular lock” and anions act as “keys”; H2PO4− can “lock” 1 by switching it from its “unlocked” conformation, however, the structurally similar HSO4− cannot “lock” receptor 1 as evidenced by single-crystal X-ray analysis (see scheme). The “unlocked–locked” conformational switching of 1 was investigated by monitoring changes in fluorescence intensity in the presence of different anions.