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 are situated orthogonally to one another. In [D-2]dichloromethane, H-1 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 [D-5]pyridine. The spatial arrangement of the two porphyr inatorhodium(III)-based rotors is a critical factor in maintaining mechanical interaction between multiple molecular rotors when changing the dynamic properties of one rotor.