Sterically hindered organometallics: multi-n-rotor (n=5, 6 and 7) molecular propellers and the search for correlated rotations

For the past several years, we have focused our attention on the design, syntheses and analyses of the dynamic behaviour of sterically encumbered complexes of the type (CnRn)MLx, where R=alkyl or aryl, n=5, 6 or 7, and MLx is an organometallic fragment. As archetypes of propellers or gear-wheels, the challenge is to construct molecules in which the internal rotations are restricted, and possibly even correlated. The incorporation of appropriate …