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A low temperature scanning tunneling microscope (STM) has been employed to investigate the insulating alkanethiol self-assembled monolayers chemisorbed on Au(111) substrates. The STM images show clear intramolecular patterns, which are voltage- and site-dependent. Theoretical simulations, using the density functional theory, reproduce the experimental STM images. Our results show that due to the chemisorption, there are new states appeared in the energy gap of the alkanethiol, and they are mainly composed of Au and S orbitals, mixed with a small amount of orbitals at the alkyl part. The STM only images the states localized at the tail carbon-hydrogen groups since the Au and S atoms are located farther from the STM tip, and the images can reflect the surface topography of such standing molecular layers. [ABSTRACT FROM AUTHOR]

Well-ordered striped structures are developed from alkanethiol self-assembled monolayers on an Au(111) surface following well-controlled annealing processes. We demonstrate here that such regular concave–convex molecular structures can be used as the templates for growing one-dimensional molecular and atomic chains. By depositing C[sub 60] molecules onto the striped surface, C[sub 60] bimolecular chains are self-assembled. Due to the breaking of C–S bonds under certain conditions, residual S atoms can form a S monoatomic chain between two adjacent stripe pairs of thoroughly lying-down molecules. Possible growth mechanisms are discussed. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]