1
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Yuan Y, Tsai P. Photodissociation dynamics of acetaldehyde at 267 nm: A computational study of the
CO
‐forming channels. J CHIN CHEM SOC-TAIP 2023. [DOI: 10.1002/jccs.202300036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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2
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Kasai T, Muthiah B, Po X, Yan C, Lin K, Tanudji J, Diño WA. Pattern analysis of the impact‐parameter dependent trajectories for the H +
H
2
exchange reaction at
T
=
3
and
300 K
: A characteristic propensity for reactive versus nonreactive trajectories found in the time‐dependent interaction potential and a roaming‐like libration motion at cold temperature. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202100539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Toshio Kasai
- Department of Chemistry National Taiwan University Taipei Taiwan
- Department of Applied Physics Osaka University Suita Japan
| | | | - Xin‐Hui Po
- Department of Chemistry National Taiwan University Taipei Taiwan
- Department of Statistics National Chengchi University Taipei Taiwan
| | - Chu‐Chun Yan
- Department of Chemistry National Taiwan University Taipei Taiwan
| | - King‐Chuen Lin
- Department of Chemistry National Taiwan University Taipei Taiwan
- Department of Chemistry, Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
| | | | - Wilson Agerico Diño
- Department of Applied Physics Osaka University Suita Japan
- Center for Atomic and Molecular Technologies Osaka University Suita Japan
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3
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Mishra D, Reino-González J, Obaid R, LaForge AC, Díaz-Tendero S, Martín F, Berrah N. Ultrafast molecular dynamics in ionized 1- and 2-propanol: from simple fragmentation to complex isomerization and roaming mechanisms. Phys Chem Chem Phys 2021; 24:433-443. [PMID: 34897321 DOI: 10.1039/d1cp04011a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Upon photoexcitation, molecules can undergo numerous complex processes, such as isomerization and roaming, leading to changes in the molecular and electronic structure. Here, we report on the time-resolved ultrafast nuclear dynamics, initiated by laser ionization, in the two structural isomers, 1- and 2-propanol, using a combination of pump-probe spectroscopy and coincident Coulomb explosion imaging. Our measurements, paired with quantum chemistry calculations, identify the mechanisms for the observed two- and three-body dissociation channels for both isomers. In particular, the fragmentation channel of 2-propanol associated with the loss of CH3 shows possible evidence of methyl roaming. Moreover, the electronic structure of this roaming methyl fragment could be responsible for the enhanced ionization also observed for this channel. Finally, comparison with similar studies done on ethanol and acetonitrile helps establish a correlation between the length of the alkyl chain and the likelihood of hydrogen migration.
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Affiliation(s)
- Debadarshini Mishra
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| | - Juan Reino-González
- Departamento de Química, Universidad Autónoma de Madrid, Módulo 13, 28049 Madrid, EU, Spain
| | - Razib Obaid
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| | - Aaron C LaForge
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| | - Sergio Díaz-Tendero
- Departamento de Química, Universidad Autónoma de Madrid, Módulo 13, 28049 Madrid, EU, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, EU, Spain.,Institute for Advanced Research in Chemical Sciences(IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, EU, Spain
| | - Fernando Martín
- Departamento de Química, Universidad Autónoma de Madrid, Módulo 13, 28049 Madrid, EU, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, EU, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nano), Campus de Cantoblanco, 28049 Madrid, EU, Spain.,Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, EU, Spain
| | - Nora Berrah
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
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4
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Tsai PY, Palazzetti F. Photodissociation dynamics of CO-forming channel of methyl formate at 193 nm: a computational study. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1977405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Po-Yu Tsai
- Department of Chemistry, National Chung Hsing University, Taichung, Taiwan
| | - Federico Palazzetti
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
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5
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Analysis of the roaming trajectories from the dynamic and kinematic perspectives – A representative study of triatomic systems. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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6
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Lin K, Tso C, Kasai T. Beyond the rule of transition state: Identification of roaming routes in some cases of carbonyl compounds. J CHIN CHEM SOC-TAIP 2021. [DOI: 10.1002/jccs.202100039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- King‐Chuen Lin
- Department of Chemistry National Taiwan University Taipei Taiwan
- Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan
| | - Cheng‐Jui Tso
- Department of Chemistry National Taiwan University Taipei Taiwan
| | - Toshio Kasai
- Department of Chemistry National Taiwan University Taipei Taiwan
- Institute of Scientific and Industrial Research Osaka University Osaka Japan
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7
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Palazzetti F, Tsai PY. Photodissociation Dynamics of CO-Forming Channels on the Ground-State Surface of Methyl Formate at 248 nm: Direct Dynamics Study and Assessment of Generalized Multicenter Impulsive Models. J Phys Chem A 2021; 125:1198-1220. [PMID: 33507759 DOI: 10.1021/acs.jpca.0c10464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The photodissociation dynamics of methyl formate in the electronic ground state S0, initiated by a 248 nm-wavelength laser, is studied by direct dynamics simulations. We analyze five channels, where four of them have as products CH3OH + CO, one leading to the formation of three fragments, H2CO + H2 + CO, and a channel characterized by a roaming transition state. The analysis of energy distribution among the degrees of freedom of the product and the comparison with experimental results previously published by other groups provide the ingredients to distinguish the examined dissociation pathways. The interpretation of the results proves that the characterization of dissociation mechanisms must rely on a dynamics approach involving multiple electronic states, including considerations on the features of the S1/S0 conical intersection. Here, we also assess the generalized multicenter impulsive model, GMCIM, that has been designed for dissociation processes with exit barriers, and the energy distribution in the products is predicted on the basis of information from the saddle points and the intrinsic reaction coordinates. Main features, advantages, limits, and future perspectives of the method are reported and discussed.
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Affiliation(s)
- Federico Palazzetti
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia 06123, Italy
| | - Po-Yu Tsai
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
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8
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Lin KC, Muthiah B, Chang HP, Kasai T, Chang YP. Halogen-related photodissociation in atmosphere: characterisation of atomic halogen, molecular halogen, and hydrogen halide. INT REV PHYS CHEM 2020. [DOI: 10.1080/0144235x.2020.1822590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- King-Chuen Lin
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
| | | | - Hsiu-Pu Chang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Toshio Kasai
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
- Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Yuan-Pin Chang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan
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9
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Roaming Dynamics and Conformational Memory in Photolysis of Formic Acid at 193 nm Using Time-resolved Fourier-transform Infrared Emission Spectroscopy. Sci Rep 2020; 10:4769. [PMID: 32179782 PMCID: PMC7075954 DOI: 10.1038/s41598-020-61642-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 11/28/2019] [Indexed: 11/09/2022] Open
Abstract
In photodissociation of trans-formic acid (HCOOH) at 193 nm, we have observed two molecular channels of CO + H2O and CO2 + H2 by using 1 μs-resolved Fourier-transform infrared emission spectroscopy. With the aid of spectral simulation, the CO spectra are rotationally resolved for each vibrational state (v = 1-8). Each of the resulting vibrational and rotational population distributions is characteristic of two Boltzmann profiles with different temperatures, originating from either transition state pathway or OH-roaming to form the same CO + H2O products. The H2O roaming co-product is also spectrally simulated to understand the interplay with the CO product in the internal energy partitioning. Accordingly, this work has evaluated the internal energy disposal for the CO and H2O roaming products; especially the vibrational-state dependence of the roaming signature is reported for the first time. Further, given a 1 μs resolution, the temporal dependence of the CO/CO2 product ratio at v ≥ 1 rises from 3 to 10 of study, thereby characterizing the effect of conformational memory and well reconciling with the disputed results reported previously between absorption and emission methods.
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10
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Ma Y, Liu J, Li F, Wang F, Kitsopoulos TN. Roaming Dynamics in the Photodissociation of Formic Acid at 230 nm. J Phys Chem A 2019; 123:3672-3677. [PMID: 30969120 DOI: 10.1021/acs.jpca.9b00724] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Roaming dynamics is observed in the photodissociation of formic acid (HCOOH) at 230 nm by using the slice imaging method. In combination with rotational state selective (2 + 1) resonance-enhanced multiphoton ionization of the CO fragments, the speed distributions of the CO fragments exhibit a low recoil velocity at low rotational levels of J = 9 and 20, while the velocity distributions of CO at high rotational levels of J = 30 and 48 show a relatively large recoil velocity. The experimental results indicate that the roaming of OH radical should be related with the formation of CO + H2O channel at the present photolysis energy. Unlike the roaming pathways occurring in H2CO that can be described by loose flat potential, our CO speed distribution analysis suggests the presence of a "tight" flat potential in the roaming dynamics of HCOOH molecules.
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Affiliation(s)
- Yujie Ma
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Centre of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , P. R. China
| | - Jiaxing Liu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Centre of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , P. R. China
| | - Fangfang Li
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Centre of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , P. R. China
| | - Fengyan Wang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Centre of Chemistry for Energy Materials , Fudan University , Shanghai 200433 , P. R. China
| | - Theofanis N Kitsopoulos
- Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Institute of Electronic Structure and Laser, FORTH, Heraklion, Greece; Department of Chemistry , University of Crete , Heraklion , Greece
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11
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Han YC. Quasiclassical trajectory calculations of CD3CHO dissociation to CD2H + DCO on a global potential energy surface. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1142/s0219633618500475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We present a quasiclassical trajectory study of the photodissociation of CD3CHO based on a global ab initio-based potential energy surface. Calculations are performed at the total energy corresponding to the photolysis wavelength of 280[Formula: see text]nm. In addition to the major radical and molecular products, CD[Formula: see text] and CD3H [Formula: see text] CO, respectively, this paper focuses on the unusual radical channel CD2H [Formula: see text] DCO, which requires a D/H exchange process before the conventional C–C bond cleavage. Five D/H exchange mechanisms are reported, which are related to the isomerizations from acetaldehyde to vinyl alcohol and back, to oxirane and back, and to the intermediate (CD–CHD–OD) and back. These D/H exchange mechanisms are in good agreement with the experimental findings [Heazlewood BR, Maccarone AT, Andrews DU, Osborn DL, Harding LB, Klippenstein SJ, Jordan MJT, Kable SH, Nat Chem 3:443, 2011].
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Affiliation(s)
- Yong-Chang Han
- Department of Physics, Dalian University of Technology, Dalian 116024, P. R. China
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