Interplay between - and - conformations of thiourea modulating ON-OFF catalysis.

The design, synthesis and operation of a readily accessible two-state switch are demonstrated. The switch initially exists in an intramolecularly hydrogen-bonded self-locked state, as evidenced by the solution-state NMR and solid-state structure. The switch can be reversibly altered between - and - conformations by adding and removing Cu ions, as evidenced by the NMR and crystallographic study.

Stimuli-Responsive Chiroptical Switching.

"Chirality" governs many fundamental properties in chemistry and biochemistry. While early investigations on stereochemistry are primarily dedicated to static chirality, there is an increasing interest in the field of dynamic chirality (chiral switches). These chiral switches are essential in controlling the directionality in molecular motors.