1
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Zou M, Hassan Y, Roy TK, McCoy AB, Lester MI. Infrared spectroscopy of the syn-methyl-substituted Criegee intermediate: A combined experimental and theoretical study. J Chem Phys 2024; 160:204309. [PMID: 38818894 DOI: 10.1063/5.0210122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 05/06/2024] [Indexed: 06/01/2024] Open
Abstract
An IR-vacuum ultraviolet (VUV) ion-dip spectroscopy method is utilized to examine the IR spectrum of acetaldehyde oxide (CH3CHOO) in the overtone CH stretch (2νCH) spectral region. IR activation creates a depletion of the ground state population that reduces the VUV photoionization signal on the parent mass channel. IR activation of the more stable and populated syn-CH3CHOO conformer results in rapid unimolecular decay to OH + vinoxy products and makes the most significant contribution to the observed spectrum. The resultant IR-VUV ion-dip spectrum of CH3CHOO is similar to that obtained previously for syn-CH3CHOO using IR action spectroscopy with UV laser-induced fluorescence detection of OH products. The prominent IR features at 5984 and 6081 cm-1 are also observed using UV + VUV photoionization of OH products. Complementary theoretical calculations utilizing a general implementation of second-order vibrational perturbation theory provide new insights on the vibrational transitions that give rise to the experimental spectrum in the overtone CH stretch region. The introduction of physically motivated small shifts of the harmonic frequencies yields remarkably improved agreement between experiment and theory in the overtone CH stretch region. The prominent features are assigned as highly mixed states with contributions from two quanta of CH stretch and/or a combination of CH stretch with an overtone in mode 4. The generality of this approach is demonstrated by applying it to three different levels of electronic structure theory/basis sets, all of which provide spectra that are virtually indistinguishable despite showing large deviations prior to introducing the shifts to the harmonic frequencies.
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Affiliation(s)
- Meijun Zou
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Yarra Hassan
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
| | - Tarun Kumar Roy
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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2
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Wannenmacher A, Lu W, Amarasinghe C, Cerasoli F, Donadio D, Ahmed M. An experimental and computational view of the photoionization of diol-water clusters. J Chem Phys 2024; 160:144303. [PMID: 38591680 DOI: 10.1063/5.0198162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/15/2024] [Indexed: 04/10/2024] Open
Abstract
In the interstellar medium, diols and other prebiotic molecules adsorb onto icy mantles surrounding dust grains. Water in the ice may affect the reactivity and photoionization of these diols. Ethylene glycol (EG), 1,2-propylene glycol, and 1,3-propylene glycol clusters with water clusters were used as a proxy to study these interactions. The diol-water clusters were generated in a continuous supersonic molecular beam, photoionized by synchrotron-based vacuum ultraviolet light from the Advanced Light Source, and subsequently detected by reflectron time-of-flight mass spectrometry. The appearance energies for the detected clusters were determined from the mass spectra, collected at increasing photon energy. Clusters of both diol fragments and unfragmented diols with water were detected. The lowest energy geometry optimized conformers for the observed EG-water clusters and EG fragment-water clusters have been visualized using density functional theory (DFT), providing insight into hydrogen bonding networks and how these affect fragmentation and appearance energy. As the number of water molecules clustered around EG fragments (m/z 31 and 32) increased, the appearance energy for the cluster decreased, indicating a stabilization by water. This trend was supported by DFT calculations. Fragment clusters from 1,2-propylene glycol exhibited a similar trend, but with a smaller energy decrease, and no trend was observed from 1,3-propylene glycol. We discuss and suggest that the reactivity and photoionization of diols in the presence of water depend on the size of the diol, the location of the hydroxyl group, and the number of waters clustered around the diol.
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Affiliation(s)
- Anna Wannenmacher
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Wenchao Lu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Chandika Amarasinghe
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Frank Cerasoli
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Davide Donadio
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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3
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Harper OJ, Chen NL, Boyé-Péronne S, Gans B. Pulsed-ramped-field-ionization zero-kinetic-energy photoelectron spectroscopy: a methodological advance. Phys Chem Chem Phys 2021; 24:2777-2784. [PMID: 34734942 DOI: 10.1039/d1cp04569e] [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 new experimental method has been developed to record photoelectron spectra based on the well-established pulsed-field-ionization zero-kinetic-energy photoelectron spectroscopy technique and inspired by the data treatment employed in slow photoelectron spectroscopy. This method has been successfully applied to two well-known systems: the X+2Πg,1/2(v+ = 0) ← X1Σ+g(v = 0) and the X+1Σ+(v+ = 2) ← X2Π1/2(v = 0) ionizing transitions of CO2 and NO, respectively. The first results highlight several advantages of our technique such as an improved signal-to-noise ratio without degrading the spectral resolution and a direct field-free energy determination. The data obtained for NO indicate that this method might be useful for studying field-induced autoionization processes.
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Affiliation(s)
- Oliver J Harper
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, 91405 Orsay, France.
| | - Ning L Chen
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, 91405 Orsay, France.
| | - Séverine Boyé-Péronne
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, 91405 Orsay, France.
| | - Bérenger Gans
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, 91405 Orsay, France.
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4
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Gray JM, Bossert J, Shyur Y, Saarel B, Briles TC, Lewandowski HJ. Characterization of a vacuum ultraviolet light source at 118 nm. J Chem Phys 2021; 154:024201. [PMID: 33445893 DOI: 10.1063/5.0033135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Vacuum ultraviolet (VUV) light at 118 nm has been shown to be a powerful tool to ionize molecules for various gas-phase chemical studies. A convenient table top source of 118 nm light can be produced by frequency tripling 355 nm light from a Nd:YAG laser in xenon gas. This process has a low efficiency, typically producing only nJ/pulse of VUV light. Simple models of the tripling process predict that the power of 118 nm light produced should increase quadratically with increasing xenon pressure. However, experimental 118 nm production has been observed to reach a maximum and then decrease to zero with increasing xenon pressure. Here, we describe the basic theory and experimental setup for producing 118 nm light and a new proposed model for the mechanism limiting the production based on pressure broadened absorption.
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Affiliation(s)
- John M Gray
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Jason Bossert
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Yomay Shyur
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Ben Saarel
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Travis C Briles
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - H J Lewandowski
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
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5
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Gope K, Livshits E, Bittner DM, Baer R, Strasser D. Absence of Triplets in Single-Photon Double Ionization of Methanol. J Phys Chem Lett 2020; 11:8108-8113. [PMID: 32897727 PMCID: PMC7595352 DOI: 10.1021/acs.jpclett.0c02445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/08/2020] [Indexed: 05/21/2023]
Abstract
Despite the abundance of data concerning single-photon double ionization of methanol, the spin state of the emitted electron pair has never been determined. Here we present the first evidence that identifies the emitted electron pair spin as overwhelmingly singlet when the dication forms in low-energy configurations. The experimental data show that while the yield of the CH2O+ + H3+ Coulomb explosion channel is abundant, the metastable methanol dication is largely absent. According to high-level ab initio simulations, these facts indicate that photoionization promptly forms singlet dication states, where they quickly decompose through various channels, with significant H3+ yields on the low-lying states. In contrast, if we assume that the initial dication is formed in one of the low-lying triplet states, the ab initio simulations exhibit a metastable dication, contradicting the experimental findings. Comparing the average simulated branching ratios with the experimental data suggests a >3 order of magnitude enhancement of the singlet:triplet ratio compared with their respective 1:3 multiplicities.
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Affiliation(s)
- Krishnendu Gope
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ester Livshits
- Fritz
Haber Research Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Dror M. Bittner
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Roi Baer
- Fritz
Haber Research Center for Molecular Dynamics and Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Daniel Strasser
- Institute
of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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6
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Wen Z, Tang X, Fittschen C, Zhang C, Wang T, Wang C, Gu X, Zhang W. Online analysis of gas-phase radical reactions using vacuum ultraviolet lamp photoionization and time-of-flight mass spectrometry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:043201. [PMID: 32357716 DOI: 10.1063/1.5135387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Abstract
A home-made vacuum ultraviolet photoionization time-of-flight mass spectrometer has been developed and coupled to an atmospheric simulation chamber operated at atmospheric pressure and to a fast flow tube at low pressure (1-10 Torr). Gas sampling from the simulation chamber is realized directly via a capillary effusive beam, and sampling from the flow tube is via a continuous molecular beam inlet. Both devices are connected simultaneously to the ionization chamber of the mass spectrometer and can be switched in-between within minutes to study gas-phase radical reactions of atmospheric interest in a large range of reaction conditions and reaction times (from milliseconds in the flow tube to hours in the simulation chamber). A cage-shaped photoionization source combined with a commercial 10.6 eV krypton lamp has been developed to provide a high ion collection efficiency along the long light path in the cage. This way, a multiplexed detection with high sensitivity down to the sub-parts per billion volume concentration range, e.g., a limit of detection of 0.3 ppbv with an accumulation time of 60 s for benzene and 1.3 ppbv for the methyl radical, is obtained. The performance and suitability of the setup are illustrated by the study of the chlorine-initiated oxidation reaction of toluene in the atmospheric simulation chamber and in the fast flow tube. Stable products and reactive intermediates have been well-determined and their reaction dynamics are discussed.
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Affiliation(s)
- Zuoying Wen
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
| | - Xiaofeng Tang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
| | - Christa Fittschen
- University Lille, CNRS, UMR 8522, PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France
| | - Cuihong Zhang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
| | - Tao Wang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
| | - Chengcheng Wang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
| | - Xuejun Gu
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
| | - Weijun Zhang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
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7
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Hemberger P, van Bokhoven JA, Pérez-Ramírez J, Bodi A. New analytical tools for advanced mechanistic studies in catalysis: photoionization and photoelectron photoion coincidence spectroscopy. Catal Sci Technol 2020. [DOI: 10.1039/c9cy02587a] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
How can we detect reactive and elusive intermediates in catalysis to unveil reaction mechanisms? In this mini review, we discuss novel photoionization tools to support this quest.
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Affiliation(s)
- Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry
- Paul Scherrer Institute
- CH-5232 Villigen PSI
- Switzerland
| | - Jeroen A. van Bokhoven
- Laboratory for Catalysis and Sustainable Chemistry
- Paul Scherrer Institute
- CH-5232 Villigen PSI
- Switzerland
- Institute for Chemical and Bioengineering
| | - Javier Pérez-Ramírez
- Institute for Chemical and Bioengineering
- Department of Chemistry and Applied Biosciences
- ETH Zurich
- Zurich
- Switzerland
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry
- Paul Scherrer Institute
- CH-5232 Villigen PSI
- Switzerland
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8
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Chen Y, Yu T, Wu X, Zhou X, Liu S, Liu F, Dai X. C–F and C–H bond cleavage mechanisms of trifluoromethane ions in low-lying electronic states: threshold photoelectron–photoion coincidence imaging and theoretical investigations. Phys Chem Chem Phys 2020; 22:13808-13817. [DOI: 10.1039/d0cp01793k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dissociative ionization of trifluoromethane (CHF3) is investigated in the 13.9–18.0 eV energy range using the threshold photoelectron–photoion coincidence (TPEPICO) technique coupled to a vacuum ultraviolet synchrotron radiation source.
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Affiliation(s)
- Yan Chen
- National Institute of Metrology
- Beijing 100013
- China
- Hefei National Laboratory for Physical Sciences at the Microscale
- Department of Chemical Physics
| | - Tongpo Yu
- Hefei National Laboratory for Physical Sciences at the Microscale
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
- China
| | - Xiangkun Wu
- Hefei National Laboratory for Physical Sciences at the Microscale
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
- China
| | - 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
| | - Shilin Liu
- Hefei National Laboratory for Physical Sciences at the Microscale
- Department of Chemical Physics
- University of Science and Technology of China
- Hefei 230026
- China
| | - Fuyi Liu
- National Synchrotron Radiation Laboratory
- University of Science and Technology of China
- Hefei 230029
- China
| | - Xinhua Dai
- National Institute of Metrology
- Beijing 100013
- China
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9
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Sheps L, Antonov I, Au K. Sensitive Mass Spectrometer for Time-Resolved Gas-Phase Chemistry Studies at High Pressures. J Phys Chem A 2019; 123:10804-10814. [DOI: 10.1021/acs.jpca.9b08393] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Leonid Sheps
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Ivan Antonov
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Kendrew Au
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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10
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Wu XK, Tang XF, Zhou XG, Liu SL. Dissociation dynamics of energy-selected ions using threshold photoelectron-photoion coincidence velocity imaging. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1811257] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Xiang-kun Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xiao-feng Tang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
| | - Xiao-guo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Shi-lin Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
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11
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Middaugh JE, Buras ZJ, Matrat M, Chu TC, Kim YS, Alecu IM, Vasiliou AK, Goldsmith CF, Green WH. A combined photoionization time-of-flight mass spectrometry and laser absorption spectrometry flash photolysis apparatus for simultaneous determination of reaction rates and product branching. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:074102. [PMID: 30068092 DOI: 10.1063/1.5024399] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 07/04/2018] [Indexed: 06/08/2023]
Abstract
In recent years, predictions of product branching for reactions of consequence to both combustion and atmospheric chemistry have outpaced validating experiments. An apparatus is described that aims to fill this void by combining several well-known experimental techniques into one: flash photolysis for radical generation, multiple-pass laser absorption spectrometry (LAS) for overall kinetics measurements, and time-resolved photoionization time-of-flight mass spectrometry (PI TOF-MS) for product branching quantification. The sensitivity of both the LAS and PI TOF-MS detection techniques is shown to be suitable for experiments with initial photolytically generated radical concentrations of ∼1 × 1012 molecules cm-3. As it is fast (μs time resolution) and non-intrusive, LAS is preferred for accurate kinetics (time-dependence) measurements. By contrast, PI TOF-MS is preferred for product quantification because it provides a near-complete picture of the reactor composition in a single mass spectrum. The value of simultaneous LAS and PI TOF-MS detection is demonstrated for the chemically interesting phenyl radical + propene system.
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Affiliation(s)
- Joshua E Middaugh
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Zachary J Buras
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Mickael Matrat
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Te-Chun Chu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Young-Seok Kim
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Ionut M Alecu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - AnGayle K Vasiliou
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - C Franklin Goldsmith
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - William H Green
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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12
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Tang X, Garcia GA, Nahon L. New insights onto dissociation of state-selected O2+ ions investigated by double imaging photoelectron photoion coincidence: The superimposed 32Πu and c4Σu− inner-valence states. J Chem Phys 2018; 148:124309. [DOI: 10.1063/1.5011046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xiaofeng Tang
- Laboratory of Atmospheric Physico-Chemistry, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031 Anhui, China
- Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
| | - Gustavo A. Garcia
- Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
| | - Laurent Nahon
- Synchrotron SOLEIL, L’Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
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13
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Vieuxmaire OPJ, Nahler NH, Jones JR, Dixon RN, Ashfold MNR. Photodissociation of state selected BrCl cations: Branching ratios and angular anisotropies of the Br product forming channels. Mol Phys 2017. [DOI: 10.1080/00268970500052197a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - N. Hendrik Nahler
- a School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK
| | - J. R. Jones
- a School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK
| | - R. N. Dixon
- a School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK
| | - M. N. R. Ashfold
- a School of Chemistry , University of Bristol , Bristol , BS8 1TS , UK
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14
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Zhang M, Guo H, Zhang L. Roaming-Mediated CH 2NH Elimination from the Ionization of Aromatic Ethylamines. ChemistryOpen 2017; 6:40-45. [PMID: 28168149 PMCID: PMC5288767 DOI: 10.1002/open.201600144] [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] [Received: 11/07/2016] [Revised: 12/12/2016] [Indexed: 12/02/2022] Open
Abstract
The ionization of aromatic ethylamines by photons or electrons leads to elimination of CH2NH fragments, supposedly deriving from the McLafferty rearrangement involving intramolecular γ‐hydrogen transfer. Using tryptamine and phenethylamine as examples, the results reported here suggest that the McLafferty mechanism is inadequate for interpreting the observations of CH2NH elimination due to much higher calculated appearance energy than experimentally measured values. Furthermore, by considering the roaming‐mediated effect, the calculated appearance energy for the elimination of CH2NH fragments is reduced and matches well with the experimental results and verifies the existence of roaming‐mediated effect. This effect could potentially be extended to explain the general CH2NH elimination of aromatic ethylamines. Due to the similar hydrogen transfer to that of the McLafferty mechanism, the roaming‐mediated effect was taken into account to suggest a novel mechanism, termed the “roaming‐modified McLafferty rearrangement”, that explains the observations of CH2NH elimination in the ionization of aromatic ethylamines. This is a reasonable modification of the McLafferty rearrangement mechanism.
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Affiliation(s)
- Mengxing Zhang
- National Synchrotron Radiation Laboratory; University of Science and Technology of China; Hefei Anhui 230029 P.R. China
| | - Huijun Guo
- Vacree Technologies Co., Ltd; Hefei Anhui 230088 P.R. China
- University of Science and Technology of China; Hefei Anhui 230029 P.R. China
| | - Lidong Zhang
- National Synchrotron Radiation Laboratory; University of Science and Technology of China; Hefei Anhui 230029 P.R. China
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15
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Chang YC, Xiong B, Bross DH, Ruscic B, Ng CY. A vacuum ultraviolet laser pulsed field ionization-photoion study of methane (CH4): determination of the appearance energy of methylium from methane with unprecedented precision and the resulting impact on the bond dissociation energies of CH4and CH4+. Phys Chem Chem Phys 2017; 19:9592-9605. [DOI: 10.1039/c6cp08200a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-resolution VUV laser PFI-PI detection method for the study of quantum-state-selected unimolecular ion dissociation.
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Affiliation(s)
| | - Bo Xiong
- Department of Chemistry
- University of California
- Davis
- USA
| | - David H. Bross
- Chemical Sciences and Engineering Division
- Argonne National Laboratory
- Argonne
- USA
| | - Branko Ruscic
- Chemical Sciences and Engineering Division
- Argonne National Laboratory
- Argonne
- USA
- Computation Institute
| | - C. Y. Ng
- Department of Chemistry
- University of California
- Davis
- USA
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16
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Xiong B, Chang YC, Ng CY. Quantum-state-selected integral cross sections for the charge transfer collision of O2+(a4Πu5/2,3/2,1/2,−1/2: v+= 1–2; J+) [O2+(X2Πg3/2,1/2: v+= 22–23; J+)] + Ar at center-of-mass collision energies of 0.05–10.00 eV. Phys Chem Chem Phys 2017; 19:29057-29067. [DOI: 10.1039/c7cp04886f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Study of spin–orbit and rovibronically selected ion-molecule reactions between O2+(a4Πu,ν+= 1–2; X2Πg,ν+= 22–23) and Ar.
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Affiliation(s)
- Bo Xiong
- Department of Chemistry
- University of California
- Davis
- USA
| | | | - Cheuk-Yiu Ng
- Department of Chemistry
- University of California
- Davis
- USA
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17
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Synchrotron threshold photoelectron photoion coincidence spectroscopy of radicals produced in a pyrolysis source: The methyl radical. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.10.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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18
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Johnson EL, Davis QC, Morse MD. Predissociation measurements of bond dissociation energies: VC, VN, and VS. J Chem Phys 2016; 144:234306. [DOI: 10.1063/1.4953782] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Eric L. Johnson
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Quincy C. Davis
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
| | - Michael D. Morse
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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19
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Kostko O, Bandyopadhyay B, Ahmed M. Vacuum Ultraviolet Photoionization of Complex Chemical Systems. Annu Rev Phys Chem 2016; 67:19-40. [DOI: 10.1146/annurev-physchem-040215-112553] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Oleg Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720;
| | - Biswajit Bandyopadhyay
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720;
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720;
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20
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Lu Z, Gao H, Xu YT, Yang L, Lam CS, Benitez Y, Ng CY. High-Resolution Threshold Photoelectron Spectroscopy by Vacuum Ultraviolet Laser Velocity-Map-Imaging Method. CHINESE J CHEM PHYS 2016. [DOI: 10.1063/1674-0068/29/cjcp1512247] [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]
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21
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Tang X, Garcia GA, Gil JF, Nahon L. Vacuum upgrade and enhanced performances of the double imaging electron/ion coincidence end-station at the vacuum ultraviolet beamline DESIRS. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:123108. [PMID: 26724007 DOI: 10.1063/1.4937624] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report here the recent upgrade of the SAPHIRS permanent photoionization end-station at the DESIRS vacuum ultraviolet beamline of synchrotron SOLEIL, whose performances have been enhanced by installing an additional double-skimmer differential chamber. The smaller molecular beam profile obtained at the interaction region has increased the mass resolution of the double imaging photoelectron photoion coincidence (i(2)PEPICO) spectrometer, DELICIOUS III, installed in the photoionization chamber of the SAPHIRS endstation, by a factor of two, to M/ΔM ∼ 1700 (FWHM). The electron kinetic energy resolution offered by the velocity map imaging (VMI) part of the spectrometer has been improved down to 2.8% (ΔE/E) as we show on the N2 photoionization case in the double skimmer configuration. As a representative example of the overall state-of-the-art i(2)PEPICO performances, experimental results of the dissociation of state-selected O2(+)(B(2)∑(g)(-), v(+) = 0-6) molecular ions performed at the fixed photon energy of hν = 21.1 eV are presented.
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Affiliation(s)
- Xiaofeng Tang
- Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
| | - Gustavo A Garcia
- Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
| | - Jean-François Gil
- Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
| | - Laurent Nahon
- Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette, France
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22
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Meier P, Rauhut G. Comparison of methods for calculating Franck–Condon factors beyond the harmonic approximation: how important are Duschinsky rotations? Mol Phys 2015. [DOI: 10.1080/00268976.2015.1074740] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Qu Z, Li C, Qin Z, Zheng X, Yao G, Zhang X, Cui Z. The design of double electrostatic-lens optics for resonance enhanced multiphoton ionization and photoelectron imaging experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:063106. [PMID: 26133827 DOI: 10.1063/1.4922521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Compared to single ion/electron-optics for velocity-map imaging, a double-focusing lens assembly designed not only allows for mapping velocity imaging of photoelectrons but also allows for investigating the vibrational structure of the intermediate states of neutral species in resonance enhanced multiphoton ionization (REMPI) spectra. In this presentation, in order to record REMPI and photoelectron spectra separately, we have constructed a compact photoelectron velocity-map imaging (VMI) apparatus combined with an opposite linear Wiley-Mclaren time-of-flight mass spectrometer (TOFMS). A mass resolution (m/Δm) of ∼1300 for TOFMS and electron energy resolution (ΔE/E) of 2.4% for VMI have been achieved upon three-photon ionization of Xe atom at 258.00 nm laser wavelength. As a benchmark, in combination of one-color (1 + 1) REMPI and photoelectron imaging of benzene via 6(1) and 6(1)1(1) vibronic levels in the S1 state, the vibrational structures of the cation and photoelectron angular anisotropy are unraveled. In addition, two-color (1 + 1') REMPI and photoelectron imaging of aniline was used to complete the accurate measurement of ionization potential (62,271 ± 3 cm(-1)). The results suggest that the apparatus is a powerful tool for studying photoionization dynamics in the photoelectron imaging using vibrational-state selected excitation to the intermediate states of neutrals based on REMPI technique.
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Affiliation(s)
- Zehua Qu
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Chunsheng Li
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Zhengbo Qin
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Xianfeng Zheng
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Guanxin Yao
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Xianyi Zhang
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Zhifeng Cui
- Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu, Anhui 241000, China
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24
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Tang X, Garcia GA, Nahon L. Adiabatic ionization energies of the overlapped A2A1 and B2E electronic states in CH3Cl+/CH3F+ measured with double imaging electron/ion coincidence. Phys Chem Chem Phys 2015; 17:16858-63. [DOI: 10.1039/c5cp02105g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The overlapped A2A1 and B2E electronic states of CH3Cl+ have been separated and their adiabatic ionization energies have been measured from an electron and ion kinetic energy correlation diagram based on their different dissociation dynamics.
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Affiliation(s)
- Xiaofeng Tang
- Synchrotron SOLEIL
- L'Orme des Merisiers
- 91192 Gif sur Yvette
- France
| | | | - Laurent Nahon
- Synchrotron SOLEIL
- L'Orme des Merisiers
- 91192 Gif sur Yvette
- France
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25
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Lu Z, Chang YC, Gao H, Benitez Y, Song Y, Ng CY, Jackson WM. Communication: direct measurements of nascent O((3)P0,1,2) fine-structure distributions and branching ratios of correlated spin-orbit resolved product channels CO(ã(3)Π; v) + O((3)P0,1,2) and CO(X̃(1)Σ(+); v) + O((3)P0,1,2) in VUV photodissociation of CO2. J Chem Phys 2014; 140:231101. [PMID: 24952514 DOI: 10.1063/1.4883515] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We present a generally applicable experimental method for the direct measurement of nascent spin-orbit state distributions of atomic photofragments based on the detection of vacuum ultraviolet (VUV)-excited autoionizing-Rydberg (VUV-EAR) states. The incorporation of this VUV-EAR method in the application of the newly established VUV-VUV laser velocity-map-imaging-photoion (VMI-PI) apparatus has made possible the branching ratio measurement for correlated spin-orbit state resolved product channels, CO(ã(3)Π; v) + O((3)P0,1,2) and CO(X̃(1)Σ(+); v) + O((3)P0,1,2), formed by VUV photoexcitation of CO2 to the 4s(10 (1)) Rydberg state at 97,955.7 cm(-1). The total kinetic energy release (TKER) spectra obtained from the O(+) VMI-PI images of O((3)P0,1,2) reveal the formation of correlated CO(ã(3)Π; v = 0-2) with well-resolved v = 0-2 vibrational bands. This observation shows that the dissociation of CO2 to form the spin-allowed CO(ã(3)Π; v = 0-2) + O((3)P0,1,2) channel has no potential energy barrier. The TKER spectra for the spin-forbidden CO(X̃(1)Σ(+); v) + O((3)P0,1,2) channel were found to exhibit broad profiles, indicative of the formation of a broad range of rovibrational states of CO(X̃(1)Σ(+)) with significant vibrational populations for v = 18-26. While the VMI-PI images for the CO(ã(3)Π; v = 0-2) + O((3)P0,1,2) channel are anisotropic, indicating that the predissociation of CO2 4s(10 (1)) occurs via a near linear configuration in a time scale shorter than the rotational period, the angular distributions for the CO(X̃(1)Σ(+); v) + O((3)P0,1,2) channel are close to isotropic, revealing a slower predissociation process, which possibly occurs on a triplet surface via an intersystem crossing mechanism.
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Affiliation(s)
- Zhou Lu
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yih Chung Chang
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Hong Gao
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yanice Benitez
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yu Song
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - C Y Ng
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - W M Jackson
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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26
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Ng CY. State-to-State Spectroscopy and Dynamics of Ions and Neutrals by Photoionization and Photoelectron Methods. Annu Rev Phys Chem 2014; 65:197-224. [DOI: 10.1146/annurev-physchem-040412-110002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cheuk-Yiu Ng
- Department of Chemistry, University of California, Davis, California 95616;
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27
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Zhang T, Wang R, Zhou L, Wang Z, Xu Q, Min S, Wang W. A computational study on the mechanism and kinetics of the reaction between CH3CH2S and OH. RSC Adv 2014. [DOI: 10.1039/c4ra07780f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Addition–elimination channels CH3CHS + H2O, CH2CH2 + HSOH, CH3CHSO + H2 and CH3CH2SH + O are the major channels in the reaction between CH3CH2S and OH.
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Affiliation(s)
- Tianlei Zhang
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong, China
| | - Rui Wang
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong, China
| | - Liting Zhou
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong, China
| | - Zhiyin Wang
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong, China
| | - Qiong Xu
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong, China
| | - Suotian Min
- School of Chemical & Environment Science
- Shaanxi University of Technology
- Hanzhong, China
| | - Wenliang Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- Xi'an, China
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28
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Hu Y, Guan J, Bernstein ER. Mass-selected IR-VUV (118 nm) spectroscopic studies of radicals, aliphatic molecules, and their clusters. MASS SPECTROMETRY REVIEWS 2013; 32:484-501. [PMID: 24122973 DOI: 10.1002/mas.21387] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 04/25/2013] [Accepted: 04/25/2013] [Indexed: 06/02/2023]
Abstract
Mass-selected IR plus UV/VUV spectroscopy and mass spectrometry have been coupled into a powerful technique to investigate chemical, physical, structural, and electronic properties of radicals, molecules, and clusters. Advantages of the use of vacuum ultraviolet (VUV) radiation to create ions for mass spectrometry are its application to nearly all compounds with ionization potentials below the energy of a single VUV photon, its circumventing the requirement of UV chromophore group, its inability to ionize background gases, and its greatly reduced fragmenting capabilities. In this review, mass-selected IR plus VUV (118 nm) spectroscopy is introduced first in a general manner. Selected application examples of this spectroscopy are presented, which include the detections and structural analysis of radicals, molecules, and molecular clusters in a supersonic jet.
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Affiliation(s)
- Yongjun Hu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, China
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29
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Xu Y, Xiong B, Chang YC, Ng CY. The translational, rotational, and vibrational energy effects on the chemical reactivity of water cation H2O+(X 2B1) in the collision with deuterium molecule D2. J Chem Phys 2013; 139:024203. [DOI: 10.1063/1.4812774] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Huang H, Chang YC, Luo Z, Shi X, Lam CS, Lau KC, Ng CY. Rovibronically selected and resolved two-color laser photoionization and photoelectron study of cobalt carbide cation. J Chem Phys 2013; 138:094301. [DOI: 10.1063/1.4790707] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Chang YC, Huang H, Luo Z, Ng CY. Communication: A vibrational study of titanium dioxide cation using the vacuum ultraviolet laser pulsed field ionization-photoelectron method. J Chem Phys 2013; 138:041101. [PMID: 23387561 DOI: 10.1063/1.4789792] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have successfully measured the vacuum ultraviolet (VUV) laser photoionization efficiency and pulsed field ionization-photoelectron (PFI-PE) spectra of cold titanium dioxide (TiO(2)) prepared by a supersonically cooled laser ablation source. The VUV-PFI-PE spectrum thus obtained exhibits long progressions of the v(2)(+)(a(1)) bending and the combination of v(1)(+)(a(1)) stretching and v(2)(+)(a(1)) bending vibrational modes of the TiO(2)(+)(X(2)B(2)) ion. The pattern of Franck-Condon factors observed indicates that the O-Ti-O bond angle of the TiO(2)(+)(X(2)B(2)) ion is significantly different from that of the TiO(2)(X(1)A(1)) neutral, whereas the change of the Ti-O bond distance is very minor upon the photoionization transition. The analysis of the PFI-PE bands has made possible the determination of the adiabatic ionization energy for TiO(2), IE(TiO(2)) = 77215.9 ± 1.2 cm(-1) (9.57355 ± 0.00015 eV), the harmonic vibrational frequencies, ω(1)(+) = 829.1 ± 2.0 cm(-1) and ω(2)(+) = 248.7 ± 0.6 cm(-1), and the anharmonic coefficients, χ(11)(+) = 5.57 ± 0.65 cm(-1), χ(22)(+) = 0.08 ± 0.06 cm(-1), and χ(12)(+) = -4.51 ± 0.30 cm(-1) for the TiO(2)(+)(X(2)B(2)) ground state.
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Affiliation(s)
- Yih-Chung Chang
- Department of Chemistry, University of California, Davis, California 95616, USA
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32
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Xu Y, Xiong B, Chang YC, Ng CY. Communication: Rovibrationally selected absolute total cross sections for the reaction H2O+(X2B1; v1+v2+v3+ = 000; N+Ka+Kc+) + D2: Observation of the rotational enhancement effect. J Chem Phys 2012; 137:241101. [DOI: 10.1063/1.4773099] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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33
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Tang X, Zhou X, Wu M, Cai Y, Liu S, Sheng L. Direct Experimental Evidence for Dissociative Photoionization of Oxygen Molecule via 2Σu– Ionic “Optical Dark” State. J Phys Chem A 2012; 116:9459-65. [DOI: 10.1021/jp3034038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaofeng Tang
- Hefei National Laboratory for
Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei,
Anhui 230026, China
- National
Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Xiaoguo Zhou
- Hefei National Laboratory for
Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei,
Anhui 230026, China
| | - Manman Wu
- Hefei National Laboratory for
Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei,
Anhui 230026, China
| | - Yu Cai
- Hefei National Laboratory for
Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei,
Anhui 230026, China
| | - Shilin Liu
- Hefei National Laboratory for
Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei,
Anhui 230026, China
| | - Liusi Sheng
- National
Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
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34
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Chang YC, Xu Y, Lu Z, Xu H, Ng CY. Rovibrationally selected ion-molecule collision study using the molecular beam vacuum ultraviolet laser pulsed field ionization-photoion method: Charge transfer reaction of N2+(X 2Σg+; v+ = 0–2; N+ = 0–9) + Ar. J Chem Phys 2012; 137:104202. [PMID: 22979852 DOI: 10.1063/1.4750248] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yih Chung Chang
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Yuntao Xu
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Zhou Lu
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Hong Xu
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - C. Y. Ng
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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35
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Mineo H, Wang Y, Chao S, Lin S. Autoionization rate constants of zero electron kinetic energy Rydberg states. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2012.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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36
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Shao Z, Li H, Zhang S, Li J, Dai Z, Mo Y, Bae YJ, Kim MS. The Jahn-Teller effect in CH 3 Cl +(X̃E2): A combined high-resolution experimental measurement and ab initio theoretical study. J Chem Phys 2012; 136:064308. [DOI: 10.1063/1.3679655] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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37
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Woodward JR, Watanabe H, Ishiuchi SI, Fujii M. A two-color tunable infrared/vacuum ultraviolet spectrometer for high-resolution spectroscopy of molecules in molecular beams. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:014102. [PMID: 22299969 DOI: 10.1063/1.3673639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe here the key technical elements of a two-color tunable IR/VUV photoionization TOF mass spectrometer system which allows a wide-range of high-resolution experiments to be performed on a diverse range of cold molecules and clusters in a molecular beam. In particular we highlight the methods we have applied to provide efficient wavelength separation of the VUV radiation from the longer wavelength components used to generate it and discuss a number of systems that we have studied with the instrument which highlight its flexibility for use in the study of molecular spectroscopy.
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Affiliation(s)
- Jonathan R Woodward
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, Japan
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38
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Gao H, Xu Y, Yang L, Lam CS, Wang H, Zhou J, Ng CY. High-resolution threshold photoelectron study of the propargyl radical by the vacuum ultraviolet laser velocity-map imaging method. J Chem Phys 2011; 135:224304. [DOI: 10.1063/1.3664864] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Yang D. Probing the bonding and structures of metal-organic radicals with zero energy electrons. Sci China Chem 2011. [DOI: 10.1007/s11426-011-4410-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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40
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Tang X, Zhou X, Niu M, Liu S, Sheng L. Dissociation of Vibrational State-Selected O2+ Ions in the B2Σg¯ State Using Threshold Photoelectron–Photoion Coincidence Velocity Imaging. J Phys Chem A 2011; 115:6339-46. [DOI: 10.1021/jp111590s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Xiaofeng Tang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoguo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Mingli Niu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shilin Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Liusi Sheng
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
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41
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Chang YC, Xu H, Xu Y, Lu Z, Chiu YH, Levandier DJ, Ng CY. Communication: Rovibrationally selected study of the N2+(X; v+ = 1, N+ = 0−8) + Ar charge transfer reaction using the vacuum ultraviolet laser pulsed field ionization-photoion method. J Chem Phys 2011; 134:201105. [DOI: 10.1063/1.3596748] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Yih Chung Chang
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Hong Xu
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Yuntao Xu
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Zhou Lu
- Department of Chemistry, University of California, Davis, California 95616, USA
| | - Yu-Hui Chiu
- Air Force Research Laboratory, SpaceVehicle Directorate, Hanscom AFB, Massachusetts 01731-3010, USA
| | - Dale J. Levandier
- Air Force Research Laboratory, SpaceVehicle Directorate, Hanscom AFB, Massachusetts 01731-3010, USA
| | - C. Y. Ng
- Department of Chemistry, University of California, Davis, California 95616, USA
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42
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de Nalda R, López-Arias M, Sanz M, Oujja M, Castillejo M. Harmonic generation in ablation plasmas of wide bandgap semiconductors. Phys Chem Chem Phys 2011; 13:10755-61. [PMID: 21547285 DOI: 10.1039/c0cp02904a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Third and fifth harmonic generation of an IR (1.064 μm) pulsed laser has been produced in ablation plasmas of the wide bandgap semiconductors CdS and ZnS. The study of the temporal behaviour of the harmonic emission has revealed the presence of distinct compositional populations in these complex plasmas. Species ranging from atoms to nanometre-sized particles have been identified as emitters, and their nonlinear optical properties can be studied separately due to strongly differing temporal behaviour. At short distances from the target (<1 mm), atomic species are mostly responsible for harmonic generation at early times (<500 ns), while clusters and nanoaggregates mostly contribute at longer times (>1 μs). Harmonic generation thus emerges as a powerful and universal technique for ablation plasma diagnosis and as a tool to determine the nonlinear optical susceptibility of ejected clusters or nanoparticles.
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Affiliation(s)
- R de Nalda
- Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain.
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Yang DS. High-Resolution Electron Spectroscopy of Gas-Phase Metal-Aromatic Complexes. J Phys Chem Lett 2011; 2:25-33. [PMID: 26295209 DOI: 10.1021/jz101550d] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
High-resolution electron spectroscopy combines pulsed field ionization zero-electron kinetic energy (ZEKE) detection with in situ laser-assisted synthesis and supersonic expansion. The technique offers sub-meV spectral resolution for the electron spectra of metal complexes and is a powerful tool to study their bonding and structures. This Perspective presents recent progress in single-photon ZEKE spectroscopy of metal-aromatic complexes and focuses on the determination of the electron spin multiplicities, metal binding sites and modes, rotational conformers, and conformational changes of these critical species in organometallic chemistry.
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Affiliation(s)
- Dong-Sheng Yang
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, United States
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Chang YC, Shi X, Lau KC, Yin QZ, Liou HT, Ng CY. Rovibronically selected and resolved two-color laser photoionization and photoelectron study of nickel carbide cation. J Chem Phys 2010; 133:054310. [DOI: 10.1063/1.3464488] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Tang X, Zhou X, Niu M, Liu S, Sun J, Shan X, Liu F, Sheng L. A threshold photoelectron-photoion coincidence spectrometer with double velocity imaging using synchrotron radiation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:113101. [PMID: 19947711 DOI: 10.1063/1.3250872] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel threshold photoelectron-photoion coincidence (TPEPICO) imaging spectrometer at the U14-A beamline of the Hefei National Synchrotron Radiation Laboratory is presented. A set of open electron and ion lenses are utilized to map velocity imaging of photoelectrons and photoions simultaneously, in which a repelling electric field using an extra lens is applied to magnify images of photoelectrons instead of traditional accelerating electric field in order to suppress the contribution of energetic electrons in the threshold photoelectron spectroscopy (TPES) and the mass-selected TPEPICO spectroscopy. The typical energy resolution of TPES is measured to be 9 meV (full width at half maximum), as shown on the (2)P(1/2) ionization of argon. The measured mass resolving power for the present TPEPICO imaging spectrometer is above 900 of M/DeltaM. Subsequently as a benchmark, oxygen molecule is photoionized by monochromatic synchrotron radiation at 20.298 eV and dissociates to an oxygen atomic ion and a neutral oxygen atom, and the translation energy distribution of oxygen atomic ion is measured by the time-sliced imaging based on mass-selected TPEPICO experiment. The kinetic energy resolution of the present ion velocity imaging is better than 3% of DeltaE/E.
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Affiliation(s)
- Xiaofeng Tang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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Abstract
In this paper, we derive the double-resonance and single-resonance two photon absorption cross sections for zero electron kinetic energy (ZEKE) spectroscopy using the inverse Born–Oppenheimer approximation (IBOA) as a basis set. Quantum chemistry calculations can then be used to evaluate the ZEKE spectra. To show how to analyze the vibronic spectra of ZEKE spectroscopy, a couple of examples have been analyzed. Quantum chemistry calculations can be employed to obtain the potential surfaces of molecules and their ions, which can be used to calculate the Franck–Condon factors involved in the vibronic transitions. We also show that using the IBOA as a basis set, the autoionization of the ZEKE states can be calculated.
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Filsinger F, Küpper J, Meijer G, Holmegaard L, Nielsen JH, Nevo I, Hansen JL, Stapelfeldt H. Quantum-state selection, alignment, and orientation of large molecules using static electric and laser fields. J Chem Phys 2009; 131:064309. [DOI: 10.1063/1.3194287] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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48
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Jones B, Zhou J, Yang L, Ng CY. High-resolution Rydberg tagging time-of-flight measurements of atomic photofragments by single-photon vacuum ultraviolet laser excitation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:123106. [PMID: 19123544 DOI: 10.1063/1.3043427] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
By coupling a comprehensive tunable vacuum ultraviolet (VUV) laser system to a velocity-mapped ion imaging apparatus, we show that high-resolution high-n Rydberg tagging time-of-flight (TOF) measurements of nascent atomic photofragments formed by laser photodissociation can be made using single-photon VUV laser photoexcitation. To illustrate this single-photon Rydberg tagging TOF method, we present here the results of the VUV laser high-n Rydberg tagging TOF measurements of O((3)P(2)) and S((3)P(2)) formed in the photodissociation of SO(2) and CS(2) at 193.3 and 202.3 nm, respectively. These results are compared to those obtained by employing the VUV laser photoionization time-sliced velocity-mapped ion imaging technique. The fact that the kinetic energy resolutions achieved in the VUV laser high-n Rydberg tagging TOF measurements of O and S atoms are found to be higher than those observed in the VUV laser photoionization, time-sliced velocity-mapped ion imaging studies show that the single-photon VUV laser high-n Rydberg tagging TOF method is useful and complementary to state-of-the-art time-sliced velocity-mapped ion imaging measurements of heavier atomic photofragments, such as O and S atoms. Furthermore, the general agreement observed between the VUV laser high-n Rydberg tagging TOF and velocity-mapped ion imaging experiments supports the conclusion that the lifetimes of the tagged Rydberg states of O and S atoms are sufficiently long to allow the reliable determination of state-resolved UV photodissociation cross sections of SO(2) and CS(2) by using the VUV laser high-n Rydberg tagging TOF method.
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Affiliation(s)
- Brant Jones
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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Xing X, Reed B, Kyung Bahng M, Wang P, Koo Woo H, Jong Baek S, Shing Lam C, Yiu Ng C. High-Resolution Infrared-Vacuum Ultraviolet Photoion and Pulsed Field Ionization-Photoelectron Methods for Spectroscopic Studies of Neutrals and Cations. CHINESE J CHEM PHYS 2008. [DOI: 10.1088/1674-0068/21/03/193-201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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50
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Yang J, Wang XB, Xing XP, Wang LS. Photoelectron spectroscopy of anions at 118.2nm: Observation of high electron binding energies in superhalogens MCl4− (M=Sc, Y, La). J Chem Phys 2008; 128:201102. [DOI: 10.1063/1.2938390] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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