Electron energy loss and thermal desorption spectroscopy of pyridine adsorbed on Pt(111)

Journal Article · Thu Oct 23 04:00:00 EDT 1986 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100280a088· OSTI ID:6909542

Grassian, V H; Muetterties, E L

The chemisorption behavior of pyridine (NC/sub 5/H/sub 5/) on a Pt(111) surface has been examined by using thermal desorption and electron energy loss spectroscopy as a function of adsorption temperature. The vibrational spectrum of pyridine adsorbed to room temperature on this surface shows intense loss peaks in the specular direction from vibrational modes which can be characterized as in-plane stretching and bending modes. This vibrational spectrum has been interpreted as the formation of an ..cap alpha..-pyridyl species (NC/sub 5/H/sub 4/) on the surface. The pyridyl moiety is bonded to the platinum surface through the nitrogen and one of the ..cap alpha..-carbon atoms with the pyridyl plane perpendicular to the metal surface. When pyridine is adsorbed at low temperature (120 K), it bonds to the surface through both the nitrogen atom and the ..pi.. and ..pi../sup */ orbitals of the pyridine ring. As the crystal is warmed to 260 K, at saturation coverage, approximately 50% of the molecules desorb as molecular pyridine. The remaining pyridine molecules partially decompose on the surface to form an ..cap alpha..-pyridyl fragment. The electron energy loss spectra of pyridine adsorbed at both low and room temperature is compared to the infrared spectra of two osmium cluster compounds: Os/sub 3/(CO)/sub 11/(NC/sub 5/H/sub 5/), a pyridine complex, and HOs/sub 3/(CO)/sup 18/NC/sub 5/H/sub 4/), a pyridyl complex.

• Research Organization: Lawrence Berkeley Lab., CA
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6909542
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 90:22; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AZINES
CHEMICAL REACTIONS
CHEMISORPTION
CRYSTALS
DATA
DESORPTION
DEUTERIUM COMPOUNDS
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY LEVELS
ENERGY-LOSS SPECTROSCOPY
EXCITED STATES
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INFORMATION
INFRARED SPECTRA
METALS
MONOCRYSTALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PLATINUM
PLATINUM METALS
PYRIDINE
PYRIDINES
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SPECTRA
SPECTROSCOPY
SURFACE PROPERTIES
TEMPERATURE EFFECTS
TRANSITION ELEMENTS
VIBRATIONAL STATES