The chemisorption of aromatic compounds, derivatized with different functional
groups, on well-defined Pd(111) surfaces was studied by a combination of Auger electron
spectroscopy (AES), low energy electron diffraction (LEED), high resolution electron
energy loss spectroscopy (HREELS), and electrochemistry (EC).
The results of this work led to the following trends and conclusions: (a) At low
concentrations, 2,5-dihydroxythiophenol (DHT) chemisorbs on a Pd surface through both
diphenolic ring and thiol group. At high concentrations, it chemisorbs only through the
thiol group. (b) There is extensive intermolecular attraction between the co-adsorbed
thiolated quinone and thiolated hydroquinone molecules. The interaction occurs through
the Pd substrate and not through space. (c) The chemisorption properties of Nheteroaromatic
compounds are pH-dependent. When the nitrogen heteroatom is
protonated, it becomes very weakly surface-active. When the nitrogen heteroatom is
deprotonated, surface activity stronger than the diphenolic ring is exhibited. (d) On a
palladium surface, the binding strengths of ligands increase in the order: phenyl ring <
quinonoid ring, < N-heteroatom < I < -SH.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-08-8159 |
| Date | 2010 August 1900 |
| Creators | Li, Ding |
| Contributors | Soriaga, Manuel P. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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