Four-component supramolecular nanorotors.

A family of supramolecular four-component nanorotors was quantitatively self-assembled from two different zinc(II) porphyrins: one representing the stator and the other the rotator with DABCO as an interconnecting axle and copper(I) ions. Rotational spinning in ROT-1' occurs at 97,000 s(-1) at 25 °C but is virtually stopped at -75 °C. The activation vs binding data suggest that spinning is an intrasupramolecular process occurring to >99.9% without dissociation. Addition and removal of two further equiv of Cu(+) reversibly switches the mode of the stochastic rotation between pure 180° and mixed 90°/180° steps and reversibly regulates the speed between 97,000 and ~80,000 s(-1).