Adsorption of bipyridyls and structurally related compounds at Pt(111) electrodes: Studies by vibrational spectroscopy (EELS), Auger spectroscopy, and electrochemistry

Journal Article · Tue May 01 04:00:00 EDT 1990 · Langmuir; (USA)

DOI:https://doi.org/10.1021/la00095a013· OSTI ID:6050702

Chaffins, S A; Gui, J Y; Kahn, B E; Lin, Chiu-Hsun; Lu, F; Salaita, G N; Stern, D A; Zapien, D C; Hubbard, A T ^[1]; Elliott, C M ^[2]

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1. Univ. of Cincinnati, OH (USA)
2. Colorado State Univ., Fort Collins (USA)

The adsorption behavior of bipyridyls and structurally related compounds from solution at well-defined Pt(111) surfaces is examined in this study to explore the influence of adsorbate molecular structure on surface bonding, molecular orientation, vibrational spectroscopy, acid-base reactivity, and electrochemical behavior of adsorbed aromatic molecules. Molecules were selected to represent various degrees of steric hindrance at the ring nitrogens. A series of carboxylic acids was also studied in order to explore the interactions between acidic moieties and the Pt(111) surface. Packing densities (moles adsorbed per unit area) were measured by means of Auger spectroscopy. Linear potential scan voltammetry was used to determine the reactivity of the adsorbed layers toward electrochemical oxidation; electrochemical reactivity of these compounds provides important clues to their mode of bonding to the surface. Surface vibrational spectra were obtained by electron energy-loss spectroscopy (EELS) and are assigned by comparison with the IR spectra of the pure compounds. The Pt(111) surfaces used in this study were characterized by LEED. Most of the subject compounds are adsorbed with the ring plane nearly perpendicular to the platinum surface; the exceptions are those prevented from doing so by steric constraints such as bulky substituents adjacent to the aromatic nitrogen atoms.

• OSTI ID: 6050702
• Journal Information: Langmuir; (USA), Journal Name: Langmuir; (USA) Vol. 6:5; ISSN 0743-7463; ISSN LANGD
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
ADSORPTION
AUGER ELECTRON SPECTROSCOPY
AZINES
BIPYRIDINES
CHEMISTRY
DATA
ELECTROCHEMISTRY
ELECTRODES
ELECTRON SPECTROSCOPY
ELEMENTS
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
MEASURING METHODS
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PLATINUM
PLATINUM METALS
PYRIDINES
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
TRANSITION ELEMENTS