Effect of resonance dipole-dipole interaction on the infrared spectra of adsorbed CF4. Experimental investigation and theoretical modeling
| Autor: | Petr D. Murzin, Anna N. Dobrotvorskaia, Alevtina V. Gatilova, Alexey A. Tsyganenko, Dmitriy N. Shchepkin, Aida V. Rudakova |
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| Rok vydání: | 2018 |
| Předmět: |
Chemistry
General Chemical Engineering Analytical chemistry General Physics and Astronomy Infrared spectroscopy Resonance 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Spectral line 0104 chemical sciences Dipole Adsorption Monolayer Wavenumber Physics::Chemical Physics Fourier transform infrared spectroscopy 0210 nano-technology |
| Zdroj: | Journal of Photochemistry and Photobiology A: Chemistry. 354:4-10 |
| ISSN: | 1010-6030 |
| Popis: | Adsorption of CF4 on ZnO has been studied by means of FTIR spectroscopy at 55–300 K. The contour of the band of the ν3 vibration in the spectra obtained is shown to depend crucially on surface coverage, due to strong resonance dipole-dipole interaction in the layer of adsorbed molecules. At high surface coverage the band is split into two components at 1320 and 1245 cm−1, about 75 cm−1 apart. The shape of the low frequency component is complicated by an “Evans hole” at 1258 cm−1. At lowest coverage only a weak band of ν3 vibration was seen at 1270–1272 cm−1; about 10 cm−1 below the corresponding wavenumber for gaseous CF4. Preliminary adsorption of CO does not affect significantly the spectrum of adsorbed CF4, leading only to slight decrease of the distance between the two components. Experimentally observed band contours were compared with those calculated theoretically using a model developed earlier for the spectra of interacting molecules in liquid phase, or dissolved in liquefied noble gases, and updated for the case of 2D systems. The calculated spectra reproduce well the splitting of the ν3 band for a monolayer, as well as the coverage and temperature dependence of the IR spectra. |
| Databáze: | OpenAIRE |
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