Theoretical characterization of hydroxyacetone (CH3-CO CH2OH) in the gas phase. Study of the far infrared region
Accurate structural and rovibrational parameters of hydroxyacetone, CH3-CO-CH2OH, are computed using highly correlated ab initio methods (CCSD(T)-F12), second order perturbation theory, and a variational procedure of reduced dimensionality, contemplating the interconversion of the conformers by inte...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/382849 |
| Acceso en línea: | http://hdl.handle.net/10261/382849 |
| Access Level: | acceso abierto |
| Palabra clave: | Hydroxyacetone Large amplitude motion Volatil organic compound Torsion Rotation Ab initio Far Infrared spectrum |
| Sumario: | Accurate structural and rovibrational parameters of hydroxyacetone, CH3-CO-CH2OH, are computed using highly correlated ab initio methods (CCSD(T)-F12), second order perturbation theory, and a variational procedure of reduced dimensionality, contemplating the interconversion of the conformers by internal rotation at low temperatures. Hydroxyacetone presents four different stable geometries. The preferred one, whose stability is prominent, is a quasi-planar structure slightly distorted due to the formation of an intramolecular hydrogen bond involving the OH hydrogen and the C=O oxygen atom. Rotational constants are computed to be A0 = 10092.77 MHz, B0 = 3808.75 MHz and C0 = 2863.19 MHz at less than 1 MHz from the experimental parameters confirming the non-planarity of the preferred conformer. Low-lying vibrational energy levels up to 500 cm−1 are determined variationally obtaining an A/E splitting of 5.227 cm−1 for the ground vibrational state. The fundamentals ν26 (C-CH2OH torsion) and ν23 (OH torsion) are found at 146.638 cm−1 (A1) and 129.583 cm−1 (E), and 349.147 cm−1 (A2) and 353.661 cm−1 (E), respectively. For the most stable conformer, a complex band structure of the far infrared spectrum due to the effects of the low methyl torsional barrier (V3 = 72 cm−1) and the non-planarity, is predicted. The subcomponents of the methyl torsion fundamental (ν27) are found at 54.566 cm−1 (A1 → A2) and 81.243 cm−1 (E → E). |
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