The device features a central ferrocene unit attached to an azobenzene handle on one side and to two zinc porphyrin moieties on the other. The zinc ions in this host molecule bind a bidentate guest compound. Shining light on the system begins a Rube Goldberg-like sequence of movements in the host that eventually twists the guest molecule, according to the Tokyo chemists. In the presence of ultraviolet light, the azobenzene isomerizes from trans to cis, stretching one end of the host molecule in the process. This induces a scissoring movement in the rest of the compound with the ferrocene acting like a pivot. The scissoring of the porphyrins twists the guest molecule like a rotor.
by Bethany Halford |
March 27, 2006