2. Molecule movement along a surface
Defuse along a prefer
directional direction
dragged by STM chip
on Au surface at 473K
Nano-car
Shirai, Y., Osgood, A. J., Zhao, Y., Kelly, K. F. & Tour, J. M.
Nano Lett. 5, 2330–2334 (2005)
Grill, L. et al.
Nature Nanotechnol. 2, 95–98 (2007).

3. Molecule movement along a surface
Defuse along a prefer
directional direction
dragged by STM chip
on Au surface at 473K
Nano-car
=>molecule act only as passive elements
Shirai, Y., Osgood, A. J., Zhao, Y., Kelly, K. F. & Tour, J. M.
Nano Lett. 5, 2330–2334 (2005)
Grill, L. et al.
Nature Nanotechnol. 2, 95–98 (2007).

4. Nanocar+ rotor unit a(2006 model) b(2012 model)
STM Image of b on Cu(111)
Model of b (calculated)
Nano-car don’t move along an Au or Cu surface
by UV light pluses(248 nm) irradiation
>interaction between wheel and surface is too strong
>energy quenched by metal surface
a)Morin, J.-F.; Shirai, Y.James M Tour,
J. Org. Lett. 2006, 8, 1713– 1716
b)Pinn-Tsong Chiang, Leonhard Grill, and James M. Tour et al
ACS Nano, 2012, 6 , 592–597

5. Electric nanocar Molecular design Exaction way Four rotor unit
Nano-car flame
electron excitation
Unidirectional
Conformational
change
Moving
liner direction
STM tip
Exciting electron
from STM tip
(STM-IETS)

6. Electric nanocar Rotor unit conversion previous research
Nature 2005,437,

7. Molecule movement along a surface
STM at 7K
1step – scanning(<60mV,<50 pA) =>No scanning (600mV, pA)
On a Cu(111) surface

8. Double bound isomerization
Electron excitation
the electron could
excite a phonon or molecules vibrational mode with an energy quantum of ħω
Check threshold
ħω/e(mV)
e⊿V≧ħω(molecule vibration energy)
=> Electron induce molecule conversion
Movement components
Double bound isomerization
Helix inversion

9. Helix inversion

10. Double bond isomerization+Helix invesion
Each data point represents 8 to40 manipulations performed on various molecules (I=30–50 pA)

11. Polarity dependence of Helix invesion
Negative bias > no movement
Positive voltage pulses -> leading to movement and helix inversion.

12. Electron excitation ħω~500meV e⊿V≧ħω(molecule vibration energy)
Double bound isomerization
ħω~500meV
e⊿V≧ħω(molecule vibration energy)
Electron induce molecule conversion
(one electron cause one reaction)
Difference between
The presence LUMO and fermi level
Helix inversion
ħω~200meV
C=C bound starching vibration

13. STM-image each isomer

14. Movement control by chirality of isomer

15. Conclusion
Scanning tunnelling microscopy confirms that activation of the conformational changes of the rotors through inelastic electron
tunnelling propels the molecule unidirectionally across a Cu(111) surface.
The system can be adapted to follow either linear or random surface trajectories or to remain stationary, by tuning the chirality of the individual motor units.
their design provides a
starting point for the exploration of more sophisticated molecular mechanical systems with directionally controlled motion.

16. Synthetic scheme 1 (rotor unit)

17. Synthetic scheme 2 (making nano-car flame)

19. 表面科学Vol. 24, No. 5, pp. 313―317, 2003

27. 表面科学Vol. 24, No. 5, pp. 313―317, 2003

28. A tunneling electron emitted from a STM tip is trapped in a molecule-induced resonant state.  The electron is dissipated into the metal surface after a short time, during which the electron could excite a phonon or molecules vibrational mode with an energy quantum of ħω