1
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Schwarting M, Seifert NA, Davis MJ, Blaiszik B, Foster I, Prozument K. Twins in rotational spectroscopy: Does a rotational spectrum uniquely identify a molecule? J Chem Phys 2024; 161:044309. [PMID: 39051838 DOI: 10.1063/5.0212632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 07/03/2024] [Indexed: 07/27/2024] Open
Abstract
Rotational spectroscopy is the most accurate method for determining structures of molecules in the gas phase. It is often assumed that a rotational spectrum is a unique "fingerprint" of a molecule. The availability of large molecular databases and the development of artificial intelligence methods for spectroscopy make the testing of this assumption timely. In this paper, we pose the determination of molecular structures from rotational spectra as an inverse problem. Within this framework, we adopt a funnel-based approach to search for molecular twins, which are two or more molecules, which have similar rotational spectra but distinctly different molecular structures. We demonstrate that there are twins within standard levels of computational accuracy by generating rotational constants for many molecules from several large molecular databases, indicating that the inverse problem is ill-posed. However, some twins can be distinguished by increasing the accuracy of the theoretical methods or by performing additional experiments.
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Affiliation(s)
- Marcus Schwarting
- Department of Computer Science, University of Chicago, Chicago, Illinois 60637, USA
| | - Nathan A Seifert
- Department of Chemistry and Chemical and Biomedical Engineering, University of New Haven, West Haven, Connecticut 06516, USA
| | - Michael J Davis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ben Blaiszik
- Data Science and Learning Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ian Foster
- Department of Computer Science, University of Chicago, Chicago, Illinois 60637, USA
- Data Science and Learning Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Kirill Prozument
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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2
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Tanaka K, Harada K, Watanabe Y, Endo Y. Fourier transform microwave spectroscopy of the 13C- and 18O-substituted tropolone. Proton tunneling effect for the isotopic species with the asymmetric potential wells. J Chem Phys 2024; 160:214311. [PMID: 38836453 DOI: 10.1063/5.0204891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/17/2024] [Indexed: 06/06/2024] Open
Abstract
Fourier-transform microwave spectroscopy has been applied for the 13C/18O-substituted tropolone to observe tunneling-rotation transitions as well as pure rotational transitions. The tunneling-rotation transitions were observed between the 13C-4 and -6 forms as well as between 13C-3 and -7, between 13C-1 and -2, and between 18O-8 and -9 (we denote these tunneling pairs as 13C-46, etc., below) although they have an asymmetric tunneling potential due to the difference in the zero point energy (ZPE). From the observed tunneling splittings ΔEij (0.9800-1.6824 cm-1), the differences in ZPE Δij for the 13C-46, -37, -12, and 18O-89 species are derived to be -0.1104, 0.5652, -1.3682, and 1.3897 cm-1 to agree well with the DFT calculation. The state mixing ratio of the tunneling states decreases drastically from (44%:56%) to (8.7%:91.3%) for 13C-46 and 18O-89 with an increase in the asymmetry Δij of the tunneling potential function. The observed tunneling-rotation interaction constants Fij decrease from 16.001 to 9.224 cm-1 as the differences in ZPE Δij increase, while the diagonal tunneling-rotation interaction constants Fu increase from 1.767 to 13.70 cm-1, explained well by the mixing ratio of the tunneling states.
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Affiliation(s)
- Keiichi Tanaka
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
- International Research Center for Space and Planetary Environmental Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Kensuke Harada
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
- International Research Center for Space and Planetary Environmental Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Yoshihiro Watanabe
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Yasuki Endo
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30093, Taiwan
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3
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Eraković M, Cvitaš MT. Tunneling splittings using modified WKB method in Cartesian coordinates: The test case of vinyl radical. J Chem Phys 2024; 160:154112. [PMID: 38639313 DOI: 10.1063/5.0204986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 03/31/2024] [Indexed: 04/20/2024] Open
Abstract
Modified WKB theory for calculating tunneling splittings in symmetric multi-well systems in full dimensionality is re-derived using Cartesian coordinates. It is explicitly shown that the theory rests on the wavefunction that is exact for harmonic potentials. The theory was applied to calculate tunneling splittings in vinyl radical and some of its deuterated isotopologues in their vibrational ground states and the low-lying vibrationally excited states and compared to exact variational results. The exact results are reproduced within a factor of 2 in most states. Remarkably, all large enhancements of tunneling splittings relative to the ground state, up to three orders in magnitude in some excited mode combinations, are well reproduced. It is also shown that in the asymmetrically deuterated vinyl radical, the theory correctly predicts the states that are localized in a single well and the delocalized tunneling states. Modified WKB theory on the minimum action path is computationally inexpensive and can also be applied without modification to much larger systems in full dimensionality; the results of this test case serve to give insight into the expected accuracy of the method.
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Affiliation(s)
- Mihael Eraković
- Department of Physical Chemistry, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia
| | - Marko T Cvitaš
- Department of Physics, University of Zagreb Faculty of Science, Bijenička Cesta 32, 10000 Zagreb, Croatia
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4
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The rate constant for the automerization of vinyl radical: A theoretical approach using the Complete Active Space Self Consistent Field method. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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5
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Nakajima M, Liu YT, Chang CH, Seiki K, Sumiyoshi Y, Ohshima Y, Tang J, Endo Y. Fine and hyperfine coupling constants of the cis-β-cyanovinyl radical, HCCHCN. Phys Chem Chem Phys 2022; 24:11585-11591. [PMID: 35522940 DOI: 10.1039/d2cp00516f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Fourier-transform microwave spectrum of the cis-β-cyanovinyl radical is re-measured for the Ka = 0 ladder of the a-type transitions up to 30 GHz and the 212-111 transition at 19.85 GHz. Four b-type transitions are also observed using a MW-MW double-resonance technique. Fine and hyperfine components observed for each rotational transition are fully assigned in the present study, and the precise molecular constants are determined for the radical. From the comparisons of the hyperfine coupling constants with those of the vinyl radicals, it is concluded that the substitution of one of the β-hydrogens by the cyano group has little effect on the electronic structure of the vinyl radical.
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Affiliation(s)
- Masakazu Nakajima
- Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Yi-Ting Liu
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300098, Taiwan.
| | - Ching Hua Chang
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300098, Taiwan.
| | - Kenji Seiki
- Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Yoshihiro Sumiyoshi
- Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Yasuhiro Ohshima
- Department of Chemistry, School of Science, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro, Tokyo 152-8550, Japan
| | - Jian Tang
- Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-Naka, Okayama 700-8530, Japan
| | - Yasuki Endo
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300098, Taiwan.
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6
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Eraković M, Cvitaš MT. Vibrational Tunneling Spectra of Molecules with Asymmetric Wells: A Combined Vibrational Configuration Interaction and Instanton Approach. J Chem Theory Comput 2022; 18:2785-2802. [PMID: 35439012 PMCID: PMC9097297 DOI: 10.1021/acs.jctc.2c00124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
A combined approach
that uses the vibrational configuration interaction
(VCI) and semiclassical instanton theory was developed to study vibrational
tunneling spectra of molecules with multiple wells in full dimensionality.
The method can be applied to calculate low-lying vibrational states in the systems with an
arbitrary number of minima, which are not necessarily equal in energy
or shape. It was tested on a two-dimensional double-well model system
and on malonaldehyde, and the calculations reproduced the exact quantum
mechanical (QM) results with high accuracy. The method was subsequently
applied to calculate the vibrational spectrum of the asymmetrically
deuterated malonaldehyde with nondegenerate vibrational frequencies
in the two wells. The spectrum is obtained at a cost of single-well
VCI calculations used to calculate the local energies. The interactions
between states of different wells are computed semiclassically using
the instanton theory at a comparatively negligible computational cost.
The method is particularly suited to systems in which the wells are
separated by large potential barriers and tunneling splittings are
small, for example, in some water clusters, when the exact QM methods
come at a prohibitive computational cost.
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Affiliation(s)
- Mihael Eraković
- Department of Physical Chemistry, Rud̵er Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia
| | - Marko T Cvitaš
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička Cesta 32, 10000 Zagreb, Croatia
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Bouallagui A, Zanchet A, Bañares L, García-Vela A. An ab initio study of the photodissociation of the vinyl radical. Phys Chem Chem Phys 2022; 24:7387-7395. [PMID: 35266503 DOI: 10.1039/d2cp00180b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photodissociation of the vinyl radical through pathways CH2CH → CH2C + H, CH2CH → CHCH + H, and CH2CH → CH2 + CH is investigated by means of high-level ab initio calculations. Potential-energy curves (PECs) along the corresponding dissociating bond distance associated with the ground and several excited electronic states involved in the above fragmentation pathways, as well as the nonadiabatic couplings connecting the different states, are obtained. The findings of several experiments on vinyl photodissociation performed at different excitation wavelengths are analyzed and explained qualitatively in the light of the present PECs. A two-dimensional representation (consisting of radial and angular coordinates to represent one of the H atoms of the CH2 group) is also used to calculate the electronic states. The surfaces obtained reflect a rich variety of conical intersections, exit barriers, and nonadiabatic couplings leading to predissociation in different regions of energy and of the two coordinates, suggesting a complex photodissociation dynamics of the CH2CH → CHCH + H pathway, with rather different fragmentation mechanisms involved. The two-dimensional results also provide interesting information on the mechanism of in-plane hydrogen migration from the CH2 group to the CH one through a high-lying transition state.
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Affiliation(s)
- A Bouallagui
- Laboratoire de Spectroscopie Atomique, Moléculaire et Applications-LSAMA LR01ES09, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092, Tunis, Tunisia.,Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain.
| | - A Zanchet
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain.
| | - L Bañares
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid (Unidad Asociada I + D + i CSIC), 28040 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanoscience), 28049 Madrid, Spain
| | - A García-Vela
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain.
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8
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Abstract
The HOSO2 radical was detected by microwave spectroscopy in a discharge plasma of a SO2/H2O gas mixture. The observed spectrum shows tunneling splittings due to the OH torsional motion. A least-squares analysis considering interactions between the two torsional sublevels of the ground vibronic state, 0+ and 0-, reproduces the observed transition frequencies with a standard deviation of ca. 3 kHz. The splitting between the two torsional sublevels is accurately determined to be 24.3 MHz for HOSO2 and 0.08 MHz for DOSO2. The potential barrier for the OH torsional motion is estimated to be 1150 cm-1 from a one-dimensional hindered rotor model.
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Affiliation(s)
- Masakazu Nakajima
- Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Yasuki Endo
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 300098, Taiwan.
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9
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Wang XG, Carrington T. A variational calculation of vibrational levels of vinyl radical. J Chem Phys 2020; 152:204311. [PMID: 32486683 DOI: 10.1063/5.0007225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the vibrational energy levels of vinyl radical (VR) that are computed with a Lanczos eigensolver and a contracted basis. Many of the levels of the two previous VR variational calculations differ significantly and differ also from those reported in this paper. We identify the source of and correct symmetry errors on the potential energy surfaces used in the previous calculations. VR has two equivalent equilibrium structures. By plotting wavefunction cuts, we show that two tunneling paths play an important role. Using the computed wavefunctions, it is possible to assign many states and thereby to determine tunneling splittings that are compared with their experimental counterparts. Our computed red shift of the hot band at 2897.23 cm-1, observed by Dong et al. [J Chem. Phys. 128, 044305 (2008)], is 4.47 cm-1, which is close to the experimental value of 4.63 cm-1.
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Affiliation(s)
- Xiao-Gang Wang
- Chemistry Department, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Tucker Carrington
- Chemistry Department, Queen's University, Kingston, Ontario K7L 3N6, Canada
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10
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Hayashi M, Matsubayashi H, Ichiyama T, Harada K, Tanaka K. Millimeter-wave spectroscopy of HDC=CH. J Chem Phys 2019; 151:184304. [DOI: 10.1063/1.5126671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Masato Hayashi
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Hiromu Matsubayashi
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Tomohiro Ichiyama
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Kensuke Harada
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
- International Center of Space Weather Science and Education, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
| | - Keiichi Tanaka
- Department of Chemistry, Faculty of Science, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
- International Center of Space Weather Science and Education, Kyushu University, Motooka, Nishiku, Fukuoka 819-0395, Japan
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11
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Horká-Zelenková V, Seyfang G, Dietiker P, Quack M. Nuclear Spin Symmetry Conservation Studied for Symmetric Top Molecules (CH3D, CHD3, CH3F, and CH3Cl) in Supersonic Jet Expansions. J Phys Chem A 2019; 123:6160-6174. [DOI: 10.1021/acs.jpca.9b02580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Veronika Horká-Zelenková
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
- J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejskova 2155/3, 182 23 Prague 8, Czech Republic
| | - Georg Seyfang
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Peter Dietiker
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Martin Quack
- Laboratorium für Physikalische Chemie, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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12
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Wu X, Zhou X, Hemberger P, Bodi A. The ionization energy of the vinyl radical: a Mexican standoff with a happy ending. Phys Chem Chem Phys 2019; 21:22238-22247. [DOI: 10.1039/c9cp04493k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Theoretical approaches and experimental spectra are confirmed as the origin transition is shown to be forbidden in vinyl photoionization.
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Affiliation(s)
- Xiangkun Wu
- Laboratory for Femtochemistry and Synchrotron Radiation
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
- Hefei National Laboratory for Physical Sciences at the Microscale
| | - Xiaoguo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
- China
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
| | - Andras Bodi
- Laboratory for Femtochemistry and Synchrotron Radiation
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
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Šmydke J, Fábri C, Sarka J, Császár AG. Rovibrational quantum dynamics of the vinyl radical and its deuterated isotopologues. Phys Chem Chem Phys 2019; 21:3453-3472. [DOI: 10.1039/c8cp04672g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rotational–vibrational states up to 3200 cm−1, beyond the highest-lying stretching fundamental, are computed variationally for the vinyl radical (VR), H2CβCαH, and the following deuterated isotopologues of VR: CH2CD, CHDCH, and CD2CD.
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Affiliation(s)
- Jan Šmydke
- MTA-ELTE Complex Chemical Systems Research Group and Laboratory of Molecular Structure and Dynamics
- Institute of Chemistry
- ELTE Eötvös Loránd University
- H-1117 Budapest
- Hungary
| | - Csaba Fábri
- MTA-ELTE Complex Chemical Systems Research Group and Laboratory of Molecular Structure and Dynamics
- Institute of Chemistry
- ELTE Eötvös Loránd University
- H-1117 Budapest
- Hungary
| | - János Sarka
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock
- USA
| | - Attila G. Császár
- MTA-ELTE Complex Chemical Systems Research Group and Laboratory of Molecular Structure and Dynamics
- Institute of Chemistry
- ELTE Eötvös Loránd University
- H-1117 Budapest
- Hungary
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14
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Ryazantsev SV, Tyurin DA, Feldman VI, Khriachtchev L. Spectroscopic characterization of the complex of vinyl radical and carbon dioxide: Matrix isolation and ab initio study. J Chem Phys 2017; 147:184301. [DOI: 10.1063/1.5000578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Sergey V. Ryazantsev
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
| | - Daniil A. Tyurin
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Vladimir I. Feldman
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Leonid Khriachtchev
- Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
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15
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Yu HG, Song H, Yang M. A rigorous full-dimensional quantum dynamics study of tunneling splitting of rovibrational states of vinyl radical C2H3. J Chem Phys 2017; 146:224307. [DOI: 10.1063/1.4985183] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hua-Gen Yu
- Division of Chemistry, Department of Energy and Photon Sciences, Brookhaven National Laboratory, Upton, New York 11793-5000, USA
| | - Hongwei Song
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
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16
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Raston PL, Liang T, Douberly GE. Infrared spectroscopy and tunneling dynamics of the vinyl radical in 4He nanodroplets. J Chem Phys 2013; 138:174302. [DOI: 10.1063/1.4802767] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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17
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Tanaka K, Harada K, Oka T. Ortho–Para Mixing Hyperfine Interaction in the H2O+ Ion and Nuclear Spin Equilibration. J Phys Chem A 2013; 117:9584-92. [DOI: 10.1021/jp312270u] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Keiichi Tanaka
- Department of Applied Chemistry, National Chiao Tung University, 1001 Ta-Hsueh Rd.,
Hsinchu 30010, Taiwan
- Department
of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan
| | - Kensuke Harada
- Department
of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan
| | - Takeshi Oka
- Department of Astronomy and Astrophysics and
Department of Chemistry, the Enrico Fermi Institute, the University of Chicago, Chicago, Illinois 60637,
United States
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18
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Huang J, Häussinger D, Gellrich U, Seiche W, Breit B, Meuwly M. Hydrogen-Bond and Solvent Dynamics in Transition Metal Complexes: A Combined Simulation and NMR-Investigation. J Phys Chem B 2012; 116:14406-15. [DOI: 10.1021/jp309412r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jing Huang
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel,
Switzerland, and
| | - Daniel Häussinger
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel,
Switzerland, and
| | - Urs Gellrich
- Institute
für Organische
Chemie und Biochemie, Albert-Ludwigs-Unversität, Freiburg, Germany
| | - Wolfgang Seiche
- Institute
für Organische
Chemie und Biochemie, Albert-Ludwigs-Unversität, Freiburg, Germany
| | - Bernhard Breit
- Institute
für Organische
Chemie und Biochemie, Albert-Ludwigs-Unversität, Freiburg, Germany
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel,
Switzerland, and
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19
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Tabor DP, Harding ME, Ichino T, Stanton JF. High-Accuracy Extrapolated Ab Initio Thermochemistry of the Vinyl, Allyl, and Vinoxy Radicals. J Phys Chem A 2012; 116:7668-76. [DOI: 10.1021/jp302527n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Daniel P. Tabor
- Institute for Theoretical Chemistry, Department of
Chemistry and Biochemistry, The University of Texas at Austin, 105 E. 24th St., A5300, Austin, Texas 78712-0165,
United States
| | - Michael E. Harding
- Institute for Theoretical Chemistry, Department of
Chemistry and Biochemistry, The University of Texas at Austin, 105 E. 24th St., A5300, Austin, Texas 78712-0165,
United States
| | - Takatoshi Ichino
- Institute for Theoretical Chemistry, Department of
Chemistry and Biochemistry, The University of Texas at Austin, 105 E. 24th St., A5300, Austin, Texas 78712-0165,
United States
| | - John F. Stanton
- Institute for Theoretical Chemistry, Department of
Chemistry and Biochemistry, The University of Texas at Austin, 105 E. 24th St., A5300, Austin, Texas 78712-0165,
United States
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20
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Cazade PA, Huang J, Yosa J, Szymczak JJ, Meuwly M. Atomistic simulations of reactive processes in the gas- and condensed-phase. INT REV PHYS CHEM 2012. [DOI: 10.1080/0144235x.2012.694694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Sharma AR, Bowman JM, Nesbitt DJ. Large-amplitude dynamics in vinyl radical: The role of quantum tunneling as an isomerization mechanism. J Chem Phys 2012; 136:034305. [PMID: 22280758 DOI: 10.1063/1.3666987] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Amit R Sharma
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322, USA
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Fábri C, Mátyus E, Császár AG. Rotating full- and reduced-dimensional quantum chemical models of molecules. J Chem Phys 2011; 134:074105. [DOI: 10.1063/1.3533950] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Hayashi M, Harada K, Lavrich R, Tanaka T, Tanaka K. Millimeter-wave spectroscopy of H(2)C=CD: Tunneling splitting and ortho-para mixing interaction. J Chem Phys 2010; 133:154303. [PMID: 20969382 DOI: 10.1063/1.3478696] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The H(2)C=CD isotopic species of vinyl radical produced in a supersonic jet expansion by ultraviolet laser photolysis was studied by millimeter-wave spectroscopy. Due to the tunneling motion of the α deuteron, the ground state is split into two components, 0(+) and 0(-). Tunneling-rotation transitions connecting the lower (0(+)) and upper (0(-)) components of the tunneling doublet were observed in the frequency region of 184-334 GHz, including three R- and two Q-branch transitions. Three and two pure rotational transitions in the K(a)=0 and 1 stacks, respectively, were also observed for each of the 0(+) and 0(-) states in the frequency region of 52-159 GHz. Least-squares analysis of the observed frequencies for the tunneling-rotation and pure rotational transitions with well resolved hyperfine structures yielded a set of precise molecular constants, among which the tunneling splitting in the ground state was determined to be ΔE(0)=1187.234(17) MHz, which is 1/14 that for H(2)C=CH. The potential barrier height derived from the observed tunneling splitting by an analysis of the tunneling dynamics using a one-dimensional model is 1545 cm(-1), consistent with the value 1568 cm(-1) obtained for the normal vinyl. The observed spectrum was found to be perturbed by a hyperfine interaction connecting ortho and para levels. The constant for the interaction, which we call the ortho-para mixing Fermi contact interaction, has been determined to be δa(F) ((β))=68.06(53) MHz. This is believed to be the first definite detection of such an interaction. By this interaction the ortho and para states of H(2)C=CD are mixed up to about 0.1%. The constant is more than 1000 times larger than spin-rotation interaction constants that cause ortho-para mixing in closed shell molecules and suggests extremely rapid conversion between the ortho and para nuclear spin isomers of H(2)C=CD.
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Affiliation(s)
- Masato Hayashi
- Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan.
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Nikow M, Wilhelm MJ, Dai HL. Vibrational modes of the vinyl and deuterated vinyl radicals. J Phys Chem A 2009; 113:8857-70. [PMID: 19594157 DOI: 10.1021/jp809735e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Following the initial report of the detection of fundamental transitions of all nine vibrational modes of the vinyl radical [Letendre , L. ; Liu , D.-K. ; Pibel , C. D. ; Halpern , J. B. ; Dai , H.-L. J. Chem. Phys. 2000 , 112 , 9209] by time-resolved IR emission spectroscopy, we have re-examined the assignments of the vibrational modes through isotope substitution. Precursor molecules vinyl chloride-d3, vinyl bromide-d3, and 1,3-butadiene-d6 are used for generating vibrationally excited vinyl-d3 through 193 nm photolysis. The nondeuterated versions of these molecules along with vinyl iodide and methyl vinyl ketone are used as precursors for the production of vinyl-h3. IR emission following the 193 nm photolysis laser pulse is recorded with nanosecond time and approximately 8 cm(-1) frequency resolution. A room-temperature acetylene gas cell is used as a filter to remove the fundamental transitions of acetylene, a photolysis product, in order to reduce the complexity of the emission spectra. Two-dimensional cross-spectra correlation analysis is used to identify the emission bands from the same emitting species and improve the S/N of the emission spectra. Isotope substitution allows the identification of several low-frequency vibrational modes. For C2H3, the assigned modes are the nu4 (CC stretch) at 1595, nu5 (CH2 symmetric bend) at 1401, nu6 (CH2 asymmetric + alpha-CH bend) at 1074, nu8 (CH2 + alpha-CH symmetric out-of-plane (oop) bend) at 944, and nu9 (CH2 + alpha-CH asymmetric oop bend) at 897 cm(-1). For C2D3, the modes are the nu5 (CD2 symmetric bend) at 1060, nu6 (CD2 asymmetric + alpha-CD bend) at 820, and nu8 (CD2 + alpha-CD symmetric oop bend) at 728 cm(-1).
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Affiliation(s)
- Matthew Nikow
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Tanaka K, Hayashi M, Ohtsuki M, Harada K, Tanaka T. Ortho-para mixing interaction in the vinyl radical detected by millimeter-wave spectroscopy. J Chem Phys 2009; 131:111101. [PMID: 19778092 DOI: 10.1063/1.3231491] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Ortho-para mixing interaction due to the coupling of nuclear and electron spins was detected for the first time by millimeter-wave spectroscopy of the deuterated vinyl radical H(2)CCD. The ground state of H(2)CCD is split by the deuteron tunneling into two components 0(+) and 0(-) separated by DeltaE(0)=1186.794(16) MHz. Rotational levels in the 0(+) and 0(-) states, one being an ortho level and the other a para level, are coupled by the interaction expressed by 0(+/-)mid R:H(')mid R:0(-/+)=(deltaa(F)/2)S(I(1)-I(2)), where I(1) and I(2) are spins of the two protons and S is the electron spin. The deltaa(F) constant has been determined to be 68.06(52) MHz. The para to ortho conversion rate constant is predicted to be 1.2x10(5) s(-1) torr(-1).
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Affiliation(s)
- Keiichi Tanaka
- Department of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan.
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Sharma AR, Braams BJ, Carter S, Shepler BC, Bowman JM. Full-dimensional ab initio potential energy surface and vibrational configuration interaction calculations for vinyl. J Chem Phys 2009; 130:174301. [DOI: 10.1063/1.3120607] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Reduced-Dimensional Quantum Approach to Tunneling Splittings Using Saddle-Point Normal Coordinates. J Phys Chem A 2009; 113:7556-62. [DOI: 10.1021/jp901027g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sakamoto A, Hayashi M, Harada K, Tanaka T, Tanaka K. Millimeter-wave spectroscopy of CoNO produced by UV laser photolysis of Co(CO)3NO. J Chem Phys 2008; 129:134303. [PMID: 19045086 DOI: 10.1063/1.2982783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The rotational spectrum of cobalt mononitrosyl (CoNO) produced by ultraviolet photolysis of Co(CO)(3)NO was observed in the millimeter-wave region. Seven rotational transitions in the ground state ranging from J = 6-5 to 12-11, with hyperfine splittings due to the Co nucleus (I = 7/2), were detected in a supersonic jet environment, while higher-frequency transitions in the range from J = 29-28 to 35-34 were measured in the ground, nu(1), nu(2), nu(3), and 2nu(2) vibrational states using a free-space absorption cell. It was confirmed from the observed spectral pattern that the CoNO molecule has a linear structure with the electronic ground state of (1)Sigma(+) symmetry. The rotational lines in the 2nu(2)(Sigma) and nu(3) states were observed to be perturbed by Fermi resonance. The equilibrium rotational constant B(e) is determined to be 4682.207(15) MHz. The CoN bond length is derived to be 1.5842 A assuming the NO bond length of 1.1823 A. A large nuclear spin-rotation interaction constant, C(I) = 123.8(11) kHz, was determined, suggesting a (1)Pi electronic excited state lying close to the ground state.
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Affiliation(s)
- Ai Sakamoto
- Department of Chemistry, Faculty of Sciences, Kyushu University, Hakozaki, Higashiku, Fukuoka 812-8581, Japan
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Nonadiabatic Chemical Dynamics: Comprehension and Control of Dynamics, and Manifestation of Molecular Functions. ADVANCES IN CHEMICAL PHYSICS 2008. [DOI: 10.1002/9780470259474.ch3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Dong F, Roberts M, Nesbitt DJ. High-resolution infrared spectroscopy of jet-cooled vinyl radical: Symmetric CH2 stretch excitation and tunneling dynamics. J Chem Phys 2008; 128:044305. [DOI: 10.1063/1.2816704] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Mil’nikov G, Nakamura H. Tunneling splitting and decay of metastable states in polyatomic molecules: invariant instanton theory. Phys Chem Chem Phys 2008; 10:1374-93. [DOI: 10.1039/b712988b] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Nesbitt DJ, Dong F. Ab initio large-amplitude quantum-tunneling dynamics in vinyl radical: a vibrationally adiabatic approach. Phys Chem Chem Phys 2008; 10:2113-22. [DOI: 10.1039/b800880a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Mil'nikov GV, Ishida T, Nakamura H. Tunneling Splitting of Energy Levels and Rotational Constants in the Vinyl Radical C2H3. J Phys Chem A 2006; 110:5430-5. [PMID: 16623471 DOI: 10.1021/jp055667s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The instanton theory newly implemented by two of the authors (G.V.M. and H.N.) is applied to hydrogen tunneling transfer in a vinyl radical. The converged instanton trajectory is found on the CCSD(T)/aug-cc-pVTZ level of an ab initio potential energy surface. The calculated ground-state energy splitting agrees with the recent high-resolution experimental data within 3% of discrepancy. The semiclassical wave function is used to estimate the splitting of the principal rotational constants of the radical.
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Affiliation(s)
- Gennady V Mil'nikov
- Department of Theoretical Studies, Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
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