Scanning Tunneling Microscopy Studies of Hydrocarbons Adsorbed on Graphite Surfaces
Scanning tunneling microscopy images of n-alkanes, n-alcohols, n-alkylthiols and n-alkylchlorides have been obtained to determine if the STM is capable of differentiating between molecules where the only difference is the functional group at the ends of a molecule. These studies indicate that there are two possible ways of differentiating between these molecules: (1) by observing differences in the relative orientation of the molecules with respect to each other, and (2) by the magnitude of the tunneling current in the vicinity of the functional group. Using the tunneling current to differentiate between functional groups also permits identification of the position of the functional group in the molecule.
KeywordsAlkyl Chain Scanning Tunneling Microscope Bright Spot Molecular Orientation Tunneling Current
Unable to display preview. Download preview PDF.
- 10.The 1-docosane thiol was supplied by J. Wilbur, J. Folkers and G. Whitesides, Department of Chemistry, Harvard University, Cambridge, MA.Google Scholar
- 12b.G.C. McGonigal, R.H. Bernhardt, Y.H Yeo, D.J. Thomson D.J., Observation of highly ordered, two-dimensional n-alkane and n-alkanol structures on graphite, J. Hoc. Sci. Technol. B9: 11071–109 (1991).Google Scholar
- 13.A.J. Groszek, Selective adsorption at graphite/hydrocarbon interface, Proc. Roy. Soc. Lund. A 314: 473–498 (1970).Google Scholar
- 15.G.C. Pimentel, A.L. McClellan, The Hydrogen Bond, W.H. Freeman and Company San Francisco and London: 201 (1960).Google Scholar