Mechanisms of reversible conformational transitions in a single molecule

Physical Review Letters

Volumn 93, Issue 19, 2004, Pages

  Qiu, X H ^a   Nazin, G V ^a   Ho, W ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ADSORPTION; ANISOTROPY; ANNEALING; APPROXIMATION THEORY; DEFORMATION; ELECTRON RESONANCE; ELECTRON TUNNELING; ELECTROSTATICS; MOLECULAR STRUCTURE; NICKEL COMPOUNDS; PHOTONS; PORPHYRINS; PROBABILITY DENSITY FUNCTION; SCANNING TUNNELING MICROSCOPY; SPUTTERING; THRESHOLD VOLTAGE;

DENSITY FUNCTIONAL THEORY (DFT); GENERALIZED GRADIENT APPROXIMATION (GGA); INELASTIC ELECTRON TUNNELING; MOLECULAR CONFORMATIONS; MOLECULAR ELECTRONIC RESONANCE;

CONFORMATIONS;

EID: 19744364370     PISSN: 00319007     EISSN: None     Source Type: Journal    
DOI: 10.1103/PhysRevLett.93.196806     Document Type: Article

References (22)

1. J. K. Gimzewski and C. Joachim, Science 283, 1683 (1999).
2. W. Ho, J. Chem. Phys. 117, 11033 (2002).
3. Z. J. Donhauser et al., Science 292, 2303 (2001).
4. J. Lahann et al., Science 299, 371 (2003).
5. T. A. Jung et al., Science 271, 181 (1996).
6. J. Gaudioso, L. J. Lauhon, and W. Ho, Phys. Rev. Lett. 85, 1918 (2000).
7. F. Moresco et al., Phys. Rev. Lett. 86, 672 (2001); 87, 088302 (2001).
8. F. Moresco et al., Phys. Rev. Lett. 86, 672 (2001); 87, 088302 (2001).
9. A. Troisi and M. A. Ratner, J. Am. Chem. Soc. 124, 14528 (2002).
10. X. H. Qiu, G. V. Nazin, and W. Ho, Science 299, 542 (2003).
11. S. -C. Lui et al., Phys. Rev. B 39, 13149 (1989).
12. K. K. Anderson et al., J. Am. Chem. Soc. 115, 12346 (1993).
13. X. H. Qiu, G. V. Nazin, A. Hotzel, and W. Ho, J. Am. Chem. Soc. 124, 14804 (2002).
14. S. Gao (to be published). The weak interactions between the closed-shell molecule and the surface are notoriously difficult to calculate within the DFT. The present state of DFT-GGA scheme does not allow reliable treatment of weakly interacting systems involving van der Waals or dipole-dipole forces.
15. J. A. Shelnutt et al., Chemical Society Reviews 27, 31 (1998).
16. X. Lu, K. W. Hipps, X. D. Wang, and U. Mazur, J. Am. Chem. Soc. 118, 7197 (1996).
17. T. Yokoyama, S. Yokoyama, T. Kamikado, and S. Mashiko, J. Chem. Phys. 115, 3814 (2001).
18. The current change is transient, faster than the sampling speed of approximately 200 μs for our instrument
19. L. Scudiero, D. E. Barlow, U. Mazur, and K. W. Hipps, J. Am. Chem. Soc. 123, 4073 (2001).
20. H. Yanagi, K. Ikuta, H. Mukai, and T. Shibutani, Nano Lett. 2, 951 (2002).
21. By bringing the tip into contact with the bare metal surface, we determined the tunneling gap to be ∼5.5 Å. The substrate and the tip apex were approximated by a pair of parallel electrodes.
22. As the tip is displaced away from the substrate surface, the tunneling current at a given bias decreases exponentially. Since the transition from type I to type II at positive bias is induced by hot electron excitation, it is likely that the apparent increase of the average transition voltage observed for increasing tip-surface distance is due to the lower flux of tunneling electrons. For sufficiently fast ramp rate and reduced tunneling current, an apparent increase in the transition voltage can occur.