Infrared, Raman, and microwave spectra of ethaneselenol and the determination of the barriers to internal rotation
| Autor: | W. E. Bucy, James R. Durig |
|---|---|
| Rok vydání: | 1977 |
| Předmět: |
Materials science
Infrared Analytical chemistry Infrared spectroscopy Atomic and Molecular Physics and Optics symbols.namesake Dipole Nuclear magnetic resonance Stark effect symbols Physical and Theoretical Chemistry Raman spectroscopy Ground state Conformational isomerism Spectroscopy Cis–trans isomerism |
| Zdroj: | Journal of Molecular Spectroscopy. 64:474-490 |
| ISSN: | 0022-2852 |
| Popis: | The infrared, Raman, and microwave spectra of gaseous ethaneselenol have been investigated. The rotational constants for both the more stable gauche and for the trans conformers are reported for the Et 78 SeH, Et 78 SeD, Et 80 SeH, and Et 80 SeD isotopic species. A proposed structure has been derived from a least-squares analysis of the moments of inertia. Dipole moment components have been obtained from each conformer using second-order Stark effects. For the gauche conformer, they are μ a = 1.42 ± 0.01, μ c = 0.37 ± 0.03, and μ total = 1.47 ± 0.01 D. For the trans isomer they are μ a = 1.217 ± 0.002, μ b = 0.850 ± 0.001, and μ total = 1.485 ± 0.002 D. The methyl barrier to internal rotation was calculated using observed frequencies obtained from the infrared and Raman spectra; a value of 3.59 ± 0.01 kcal/mole was obtained. Asymmetric potential functions have been calculated for both the EtSeH and EtSeD isotopic species. For the light species the potential constants for internal rotation around the CSe bond are V 2 = −96.4 ± 1, V 3 = 432 ± 4, and V 6 = −20 ± 2 cm −1 . The difference between ground-state energy levels of the two conformers was found to be 66 cm −1 . A vibrational assignment based on infrared and Raman spectra of the gaseous phase is presented. |
| Databáze: | OpenAIRE |
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