AVS 53rd International Symposium
    Surface Science Thursday Sessions
       Session SS2+EM-ThM

Paper SS2+EM-ThM9
Thiol-Modified Diamondoid Monolayers on Gold Studied with Near-Edge X-ray Absorption Fine Structure Spectroscopy

Thursday, November 16, 2006, 10:40 am, Room 2004

Session: Self-Assembled Monolayers
Presenter: T.M. Willey, Lawrence Livermore National Laboratory
Authors: T.M. Willey, Lawrence Livermore National Laboratory
J.D. Fabbri, Stanford University
J.R.I. Lee, Lawrence Livermore National Laboratory
P.R. Schreiner, Justus-Liebig University Giessen, Germany
A.A. Fokin, Justus-Liebig University Giessen, Germany
B.A. Tkachenko, Justus-Liebig University Giessen, Germany
N.A. Fokina, Justus-Liebig University Giessen, Germany
J.E. Dahl, MolecularDiamond Technologies
R.M.K. Carlson, MolecularDiamond Technologies
S.G. Liu, MolecularDiamond Technologies
T. van Buuren, Lawrence Livermore National Laboratory
N.A. Melosh, Stanford University
Correspondent: Click to Email
Higher diamondoids, hydrocarbon cages with a diamond-like structure, have evaded laboratory synthesis and have only recently been purified from petroleum sources. Initial calculations on these unique diamond-like molecules show they may have highly desirable properties similar to hydrogen-terminated diamond surfaces. Readily available adamantane, the smallest diamondoid, can be thiolated and has shown to absorb on gold with high coverage. The availability of diamantane, triamantane, and tetramantanes opens new possibilities for surface-modification as multiple sites are available for thiol or other chemical functionalization. Surface-attached diamondoids have technological possibilities as high-efficiency field emitters in molecular electronics, as seed crystals for diamond growth, or in other nanotechnological applications, and fundamental studies of the properties of these molecules are a necessary precursor. We have investigated the effects of thiol substitution position and polymantane order on diamondoid film morphology. Using Near-Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS) we show that the orientation of the diamondoids within each type of monolayer depends highly upon both the location of the thiol and the diamondoid used. We thus demonstrate control over the assembly, and hence the surface properties, of this exciting new class of diamond-like carbon molecules.