Molecular elevator
A cartoon representation of the molecular elevator. The elevator, which is only about 2.5 nm in height and about 3.5 nm in diameter, consists of two mechanically interlocked components - a trifurcated rig-like component (gray) containing two notches (green and blue) at different levels in each of its three legs, which are interlocked by a platform (red) made up of loops in the form of three macrocycles fused trigonally to a central floor. The platform can be made to stop at two different levels upon subsequent addition of acid and base. The three legs of the rig carry bulky feet (dark gray) that prevent loss of the platform.