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Albert S, Bauerecker S, Bekhtereva ES, Bolotova IB, Hollenstein H, Quack M, Ulenikov ON. High resolution FTIR spectroscopy of fluoroform 12CHF3 and critical analysis of the infrared spectrum from 25 to 1500 cm−1. Mol Phys 2018. [DOI: 10.1080/00268976.2017.1392628] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- S. Albert
- Physical Chemistry, ETH-Zürich, Zürich, Switzerland
| | - S. Bauerecker
- Physical Chemistry, ETH-Zürich, Zürich, Switzerland
- Institut für Physikalische und Theoretische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - E. S. Bekhtereva
- Physical Chemistry, ETH-Zürich, Zürich, Switzerland
- Institute of Physics and Technology, National Research Tomsk Polytechnic University, Tomsk, Russia
| | | | | | - M. Quack
- Physical Chemistry, ETH-Zürich, Zürich, Switzerland
| | - O. N. Ulenikov
- Physical Chemistry, ETH-Zürich, Zürich, Switzerland
- Institute of Physics and Technology, National Research Tomsk Polytechnic University, Tomsk, Russia
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Albert S, Bekhtereva E, Bolotova I, Chen Z, Fábri C, Hollenstein H, Quack M, Ulenikov O. Isotope effects on the resonance interactions and vibrational quantum dynamics of fluoroform 12,13CHF 3. Phys Chem Chem Phys 2017; 19:26527-26534. [PMID: 28956885 DOI: 10.1039/c7cp04762b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a comparison of the analysis of the low energy spectrum of 13CHF3 and 12CHF3 from the THz (FIR) range to the ν1 fundamental at high resolution (δ[small nu, Greek, tilde] < 0.001 cm-1 or otherwise Doppler limited) on the basis of FTIR spectra taken both with ordinary light sources and with the synchrotron radiation from the Swiss Light Source. Several vibrational levels are accurately determined including, in particular, the 2ν4 CH-bending overtone and the ν1 CH-stretching fundamental of 13CHF3. Comparison of experimental results with those from accurate full dimensional vibrational calculations allows for a study of the time-dependent quantum dynamics of intramolecular vibrational redistribution (IVR) in the CH chromophore both on short time scales (fs) and longer time scales (ps) when coupling to the lower frequency modes becomes important and where the 12C/13C isotope effects are very large.
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Affiliation(s)
- Sieghard Albert
- Physical Chemistry, ETH-Zürich, CH-8093, Zürich, Switzerland.
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Cobos CJ, Croce AE, Luther K, Troe HJ. Experimental and Modelling Study of the Unimolecular Thermal Decompostion of CHF3. Z PHYS CHEM 2011. [DOI: 10.1524/zpch.2011.0145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The unimolecular thermal decomposition reaction CHF3 (+M)→CF2 + HF (+M) was studied in shock waves by monitoring the UV absorption of the forming CF2 radicals. The results of the present and previous experiments on the temperature and pressure dependence of the rate constants are analyzed in terms of unimolecular rate theory. Falloff curves (for 1500–1900 K) are represented in terms of fitted limiting low pressure rate constants k
0 = [Ar] 1.1 × 1016exp(−53.0 kcal mol−1/RT) cm3mol−1s−1, limiting high pressure rate constants k
∞ = 1.25 × 1015 exp(−75.8 kcal mol−1/RT) s−1 from quantum-chemical calculations, and center broadening factors F
cent = 0.170(± 0.04) including strong and weak collision contributions from unimolecular rate theory. With these results, approximate analytical expressions of the falloff curves well represent the measured and calculated rate constants over wide ranges of pressure and temperature.
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Affiliation(s)
- Carlos J. Cobos
- Universidad Nacional de La Plata, INIFTA, La Plata, Argentinien
| | - A. E. Croce
- Universidad Nacional de La Plate, Facultad de Ciencias Exactas, Argentinien
| | - K. Luther
- Universität Göttingen, Institut für Physikalische Chemie, Göttingen
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Jaeger HM, Schaefer HF, Demaison J, Császár AG, Allen WD. Lowest-Lying Conformers of Alanine: Pushing Theory to Ascertain Precise Energetics and Semiexperimental Re Structures. J Chem Theory Comput 2010; 6:3066-78. [DOI: 10.1021/ct1000236] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Heather M. Jaeger
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d’Ascq Cedex, France, and Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Henry F. Schaefer
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d’Ascq Cedex, France, and Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Jean Demaison
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d’Ascq Cedex, France, and Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Attila G. Császár
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d’Ascq Cedex, France, and Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
| | - Wesley D. Allen
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, Laboratoire de Physique des Lasers, Atomes et Molécules, UMR CNRS 8523, Université de Lille I, 59655 Villeneuve d’Ascq Cedex, France, and Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, H-1518 Budapest 112, P.O. Box 32, Hungary
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