A Fourier transform infrared reflection absorption spectroscopy study of chemisorbed PF3on Ni(111): Coverage and temperature dependence
| Autor: | Xingcai Guo, Michael Trenary, John T. Yates, Vijay K. Agrawal |
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| Rok vydání: | 1991 |
| Předmět: |
Absorption spectroscopy
Infrared Chemistry Intermolecular force Analytical chemistry General Physics and Astronomy Infrared spectroscopy Molecular physics Fourier transform spectroscopy symbols.namesake Fourier transform Reflection (mathematics) Chemisorption symbols Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Chemical Physics. 94:6256-6263 |
| ISSN: | 1089-7690 0021-9606 |
| Popis: | The P–F symmetric stretch fundamental mode of PF3 chemisorbed on the Ni(111) surface has been measured with Fourier transform infrared reflection absorption spectroscopy. Strong adsorbate–adsorbate interactions lead to a net increase in frequency from 858 cm−1 at the lowest coverage to 916 cm−1 at the highest coverage. At 273 K the band shape is symmetric with a FWHM of 6 cm−1 at both low and high coverages indicating a uniform environment for PF3 molecules in both coverage limits. At intermediate coverages the band is broad and asymmetric with unresolved components indicating a wide distribution of intermolecular distances on the surface. The low coverage frequency is 40 cm−1 lower than in the Ni(PF3)4 complex indicating interactions between the F atoms of PF3 and nearest‐neighbor Ni atoms on the Ni(111) surface. This interaction is reduced as higher lying torsional states of chemisorbed PF3 become thermally populated, leading to a strong temperature dependence of the P–F stretch band shape at low coverages. |
| Databáze: | OpenAIRE |
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