Mechanically interlocked porphyrin gears propagating two different rotational frequencies

We report a new supramolecular rotor (1), in which a lanthanum(III) bis(porphyrinate)s double-decker (LaDD) bears two porphyrinatorhodium(III)-based rotors whose planes aresituated orthogonally to one another. In [D ₂]dichloromethane, ¹H NMR spectral results indicated that rotational information was transmitted from the LaDD rotor to two porphyrinatorhodium(III)-based rotors through mechanical interaction of the teeth of the rotors. Mechanical interaction was achieved among the multiple rotors in 1 even after switching the rotational activity of the LaDD rotor by using [D₅]pyridine. The spatial arrangement of the two porphyrinatorhodium(III)-based rotors is a critical factor in maintaining mechanical interaction between multiple molecular rotors when changing the dynamic properties of one rotor.