Manifestation of Fermi resonance in the vibrational spectra of 5-ioduracil, and its deutero-derivatives isolated in low-temperature Ar matrices
| Autor: | Yu. V. Rubin, Victor A. Karachevtsev, S. A. Egupov, L. F. Belous, A. Yu. Ivanov |
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| Rok vydání: | 2014 |
| Předmět: |
education.field_of_study
Materials science Argon Physics and Astronomy (miscellaneous) Population Resolution (electron density) General Physics and Astronomy chemistry.chemical_element Infrared spectroscopy Tautomer Molecular physics Nuclear magnetic resonance chemistry Density functional theory Fermi resonance Perturbation theory education |
| Zdroj: | Low Temperature Physics. 40:1097-1103 |
| ISSN: | 1090-6517 1063-777X |
| Popis: | The FTIR spectra of isolated 5-ioduracil (5IU) molecules, and its deutero-derivatives, were obtained in low-temperature (T = 8 K) argon matrices in the frequency range of 3800–200 cm−1, with a resolution of 0.3 cm−1. The tautomer population is estimated at the evaporation temperature 395 K, using DFT (functionals B3LYP and B2PLYP) and MP2 quantum-mechanical methods. It is found that the main keto tautomer population in 5IU is above 99.8%. 5IU vibrational spectra are calculated using the DFT/B3LYP method and 6-311++G(df,pd) basis, and the calculated frequencies are corrected using a second order polynomial. It is found that in the region of vCO stretching vibrations of 5IU molecules, a triple Fermi resonance is manifested between the fundamental vC4O mode, and the combinational vibrations with frequencies 1745.3 and 1722.5 cm−1. Six combination modes in the region of ring stretching vibrations, and in-plane deformational vibrations, of 5IU are found. This classification of the vibrational spectrum bands of... |
| Databáze: | OpenAIRE |
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