High-resolution rovibrational analysis of vibrational states of A2 symmetry of the dideuterated methane CH2D2: the levels ν 5 and ν 7 + ν 9 |
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Authors: | O N Ulenikov§ E S Bekhtereva¶ S V Grebneva H Hollenstein |
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Institution: | 1. Laboratory of Molecular Spectroscopy, Physics Department , Tomsk State University , Tomsk 634050, Russia;2. Physical Chemistry , ETH Zürich, CH-8093 Zürich, Switzerland |
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Abstract: | The infrared spectrum of the CH2D2 molecule has been measured in the region 900–1500?cm?1 on a Bomem DA002 Fourier transform spectrometer with a resolution of 0.0024?cm?1 (FWHM, unapodized). Transitions belonging to the hot bands ν 7?+?ν9?ν 7, ν7?+?ν9? ν 9, ν5?+?ν7?ν5, and ν5?+?ν9?ν5 were extracted from the recorded spectra to determine the rovibrational energies of the A2 symmetry vibrational states (v 7?=?v 9?=?1) at 2329.698?cm?1 and (v 5 ?=?1) at 1331.409?cm?1. Vibrational energies as well as rotational and centrifugal distortion parameters of the (v 7?=?v 9=1) and (v 5?=?1) states were determined that reproduce the experimental rovibrational energy levels of the (v 7?=?v 9?=?1) and (v 5?=?1) vibrational states with a d rms deviation of 0.0017 and 0.0006?cm?1, respectively. The results are discussed in relation to the equilibrium structure of methane, which is redetermined here from the experimental data, and in relation to its potential hypersurface and anharmonic vibrational dynamics. |
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Keywords: | Vibrational states Dideuterated methane Rovibrational analysis Infrared spectroscopy Isotopes Methane structure |
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