Flat lying pin-stripe phase of decanethiol self-assembled monolayers on Au(111)

Langmuir

Volumn 14, Issue 23, 1998, Pages 6693-6698

  Staub, R ^a   Toerker, M ^a   Fritz, T ^a   Schmitz Hubsch T ^a   Sellam, F ^a   Leo, K ^a  

^a DRESDEN UNIVERSITY OF TECHNOLOGY   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ANNEALING; GOLD; MOLECULAR STRUCTURE; MONOLAYERS; SCANNING TUNNELING MICROSCOPY; SUBSTRATES; SULFUR COMPOUNDS; SURFACE STRUCTURE;

DECANETHIOL; FLAT LYING PIN-STRIPE PHASE; SELF-ASSEMBLED MONOLAYERS;

METALLIC FILMS;

EID: 0032204356     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la980717o     Document Type: Article

References (29)

1. Dubois, L. H.; Nuzzo, R. G. Annu. Rev. Phys. Chem. 1992, 43, 437.
2. Delamarche, E.; Michel, B.; Biebuck, H. A.; Gerber, Ch. Adv. Mater. 1996, 8, 719.
3. Fenter, P.; Eberhardt, A.; Eisenberger, P. Science 1994, 266, 1216.
4. The term molecular surface density is herein defined as the number of molecules per area and should not be confused with surface coverage, i.e., the ratio of covered to total substrate surface.
5. Chidsey, C. E. D.; Liu, G.-Y.; Rowntree, P.; Scoles, G. J. Chem. Phys. 1989, 91, 4421.
6. Widrig, C. A.; Alves, C. A.; Porter, M. D. J. Am. Chem. Soc. 1991, 113, 2805.
7. Alves, C. A.; Smith, E. L.; Porter, M. D. J. Am. Chem. Soc. 1992, 114, 1222.
8. Dubois, L. H.; Zegarski, B. R.; Nuzzo, R. G. J. Chem. Phys. 1993, 98, 678.
9. Camillone, N., III; Chidsey, C. E. D.; Liu, G.; Scoles, G. J. Chem. Phys. 1993, 98, 4234.
10. Poirier, G. E.; Tarlov, G. E. Langmuir 1994, 10, 2853.
11. Sellers, H.; Ulman, A.; Shnidman, Y.; Eilers, J. E. J. Am. Chem. Soc. 1993, 115, 9389.
12. Yeganeh, M. S.; Dougal, S. M.; Polizotti, R. S.; Rabinowitz, P. Phys. Rev. Lett. 1995, 74, 1811.
13. Fenter, P.; Schreiber, F.; Berman, L.; Scales, G.; Eisenberger, P.; Bedzyk, M. J. Submitted to Surf. Sci.
14. Gerlach, R.; Polanski, G.; Rubahn, H.-G. Appl. Phys. A 1997, 65, 375.
15. Camillone, N., III; Eisenberger, P.; Leung, T. Y. B.; Schwartz, P.; Scoles, G. Poirier, G. E.; Tarlov, M. J. J. Chem. Phys. 1994, 101, 11031.
16. Camillone, N., III; Leung, T. Y. B.; Schwartz, P.; Eisenberger, P.; Scoles, G. Langmuir 1996, 12, 2737.
17. Poirier, G. E.; Tarlov, M. J.; Rushmeier, H. E. Langmuir 1994, 10, 3383.
18. Poirier, G. E.; Tarlov, M. J. J. Phys. Chem. 1995, 99, 10966.
19. Poirier, G. E.; Pylant, E. D. Science 1996, 272, 1145.
20. Kang, J.; Rowntree, P. A. Langmuir 1996, 12, 2813.
21. Yamada, R.; Uosaki, K. Langmuir 1997, 13, 5218.
22. Himmel, H.-J.; Wöll, Ch.; Gerlach, R.; Polanski, G.; Rubahn, H.-G. Langmuir 1997, 13, 602.
23. DeRose, J. A.; Thundat, T.; Nagahara, L. A.; Lindsay, S. M. Surf. Sci. 1991, 256, 102.
24. Omicron GmbH, Taunusstein, Germany.
25. For the theoretical calculations we used the PM3 method as implemented in HyperChem 5.01 of Hypercube, Inc., Waterloo, Canada. Prior to the orbital calculation, a full structural optimization was performed, resulting in linear decanthiol and zigzag-shaped disulfide molecules, respectively.
26. In addition to the didecyl disulfide, we included a dimethyl disulfide in our calculations. This enabled us to check the results of the semiempirical PM3 method by ab initio restricted Hartree-Fock calculations with the 6-31G(d) basis set, done by means of the Gaussian94W program of Gaussian, Inc., Pittsburgh, PA, The deviations found are smaller than 0.02 Å.
27. This is a valid assumption since for a bias of +2 V applied to the sample the Fermi level of the tip is well in the HOMO-LUMO gap of the decanethiol molecule. Thus electron tunneling through the molecule should occur mainly through the front orbitals. As the HOMO and LUMO are localized around the sulfur atom, we can assign the bright spots to the binding sites of the sulfur to the Au(111) surface.
28. We found an electron density maximum separation of 3.1, 3.2, and 2.1Å for HOMO, LUMO, and the total charge density, respectively. The calculations were performed with PM3 (see ref 25).
29. Beardmore, K. M.; Kress, J. D.; Bishop, A. R.; Grønbech-Jensen, N. Synth. Met. 1997, 84, 317.