Researchers in Japan have put a new spin on molecular machines. In the March 23 issue of Nature, Takuzo Aida and coworkers report a system in which the photoresponsive motion of a host molecule induces the controlled rotation of a guest molecule.
The design hinges upon the photoisomerization of an azobenzene group, which can be switched between cis and trans configurations when exposed to either ultraviolet or visible light. The resulting change in molecular geometry causes two porphyrin paddles to pivot around a central ferrocene unit, translating this twisting motion to a rotor-like molecule that is sandwiched between them.
The authors suggest that this proof-of-principle demonstration of coupled molecular motion may be a significant factor in the control of larger integrated systems. I guess we’ll have to wait and see – let’s hope we’re not left twisting in the wind…
Stuart Cantrill (Associate Editor, Nature Nanotechnology)