Investigation of triptycene-based surface-mounted rotors

We have used computer simulations to investigate the potential of triptycene-based rotors mounted on the Si(100)-2 x 1 surface. Two concepts are explored for attaching the triptycene to the Si surface: -COOH and -OH groups. We find the -COOH produces an axle with too many degrees of freedom, creating too flexible a coupling to the substrate. By contrast, the calculations suggest that the -OH coupling should provide a useful stiff axle.