Electronic structure of solid pyridine and pyridine adsorbed on polycrystalline silver
| Autor: | J. Schmidt-May, J.-H. Fock, E.E. Koch |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Radiation
Valence (chemistry) Binding energy Analytical chemistry Synchrotron radiation Electronic structure Photon energy Condensed Matter Physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials chemistry.chemical_compound Crystallography Full width at half maximum chemistry Pyridine Crystallite Physical and Theoretical Chemistry Spectroscopy |
| Zdroj: | Journal of Electron Spectroscopy and Related Phenomena. 34:225-234 |
| ISSN: | 0368-2048 |
| DOI: | 10.1016/0368-2048(84)80067-5 |
| Popis: | The electronic structure of the valence bands of polycrystalline films of pyridine (C 5 H 5 N), including all valence levels extending from initial energies of 4 down to 30 eV ( E VAC = 0), has been determined from photoelectron energy distribution measurements for photon energies 20eV ⩽ h ν ⩽ 170 eV, using synchrotron radiation. The valence bands showing a one-to-one correspondence to the gas phase, a rigid relaxation shift of δ e r = 0.3 eV for the vertical binding energies, and a considerable solid state broadening (≳ 0.5 eV) are assigned in comparison to recent MO calculations. By tuning the photon energy and thereby achieving high surface sensitivity for h ν around 45 eV, we have also studied pyridine adsorbed at 120 K (6 Langmuir) on in situ prepared polycrystalline Ag-substrates. Thus, we were able to study in detail the surface electronic structure in the range of the Ag 4 d bands. Due to a strong mixing of substrate 4 d and pyridine 2 b 1 (π), 1 a 2 (π) and 7 a 1 ( n ) energy levels, the surface electronic structure is strongly modified in the upper part of the 4 d bands, and a strong and sharp (0.4 eV FWHM) surface resonance at an energy of 3.7 e V below E AG F is observed, which we attribute to a 4 d -7 a 1 ( n ) bonding of the nitrogen lone-pair orbital. |
| Databáze: | OpenAIRE |
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