Light driven molecular lock comprises a Ru(bpy) 2 (hpip) complex and cucurbit[8]uril.

Here, complex 1 ([Ru(bpy) 2 (hpip)] 2+ -MV 2+ ) and CB[8] can form a stable 1 : 1 inclusion complex in aqueous solution, resembling a U-shaped conformation. Upon light irradiation, two complex 1 were reversibly locked through the formation of a MV˙ + radical dimer that is stabilized in the cavity of CB[8] with Ru complexes as blockers, in which complex 1 was transformed from a U-shaped conformation to a interlocked complex. This study provided a feasible strategy for the fabrication of a photo-driven supramolecular machine resembling a "lock".