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Chen Y, Wu X, Zhou X, Yang X, Dai X, Liu S. The N + Formation Mechanism of Vibrationally Selected N 2O + Ions in the C 2Σ + State: A TPEPICO Imaging Study. J Phys Chem A 2024; 128:4439-4447. [PMID: 38780798 DOI: 10.1021/acs.jpca.4c00494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
The N-NO bond fission of N2O+(C2Σ+) ions can produce two major fragment ions, NO+ or N+. In contrast to the dominant NO+ fragment ion, the N+ formation mechanism remains unclear to date. Here, dissociative photoionization of N2O via the C2Σ+ ionic state has been reinvestigated using a combined approach of threshold photoelectron-photoion coincidence (TPEPICO) velocity imaging and quantum chemical calculations. Accompanying the N+(3P) formation, the NO(X2Π) neutral fragment with low and high vi-rotational distributions was identified, based on the N+ speed and angular distributions derived from the TPEPICO images. In particular, the excitation of the symmetric stretching ν1+ mode promotes the formation of high rotational components, while the asymmetric stretching ν3+ mode shows the exact opposite effect. According to our calculated multistate potential energy surfaces, intersystem crossing from C2Σ+ to 14Π exclusively provides feasible decomposition pathways to produce the N+ fragment. In a slightly bent geometry, spin-orbit couplings between C2Σ+ and two substates of 14Π, 14A' or 14A″, play a crucial role in the N+ formation from vibrationally selected N2O+(C2Σ+) ions. The mechanism also provides new insights into the charge transfer reaction of N+ + NO → N + NO+.
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Affiliation(s)
- Yan Chen
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xiangkun Wu
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xiaoguo Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Xinlang Yang
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xinhua Dai
- National Institute of Metrology, Beijing 100013, China
| | - Shilin Liu
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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Herburger H, Wirth V, Hollenstein U, Merkt F. Pulsed-ramped-field-ionisation zero-kinetic-energy photoelectron spectroscopy of the metastable rare-gas atoms Ar, Kr and Xe. Phys Chem Chem Phys 2023; 25:22437-22454. [PMID: 37581215 PMCID: PMC10445426 DOI: 10.1039/d3cp02881j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 07/24/2023] [Indexed: 08/16/2023]
Abstract
The photoionisation of the metastable rare-gas atoms Rg = Ar, Kr and Xe is investigated at the Rg+ […](ns)2(np)5 2P3/2 ← Rg[…](ns)2(np)5((n + 1)s) 13P2 photoionisation threshold (n = 3, 4 and 5 for Ar, Kr and Xe) using the technique of pulsed-ramped-field-ionisation zero-kinetic-energy (PRFI-ZEKE) photoelectron spectroscopy. This technique, which monitors the field ionisation of high Rydberg states induced by a slowly growing electric-field ramp after a prepulse of opposite polarity, was recently introduced to record photoelectron spectra with high resolution and high sensitivity [Harper, Chen, Boyé-Péronne and Gans, Phys. Chem. Chem. Phys., 2022, 117, 9353]. A tunable UV laser system with a bandwidth of 30 MHz is used here to establish the factors determining the resolution and overall accuracy of this new method. In particular, the effects of stray electric fields, and of the magnitude of the prepulse and the field ramp on PRFI-ZEKE photoelectron spectra are studied by combining experiments with numerical simulations of the field-ionisation of high Rydberg states and of the electron flight times from the ionisation spot to the detector. A spectral resolution of 0.05 cm-1 is demonstrated in the photoelectron spectrum of metastable Ar.
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Affiliation(s)
- Holger Herburger
- Institute for Molecular Physical Science, ETH Zürich, 8093 Zürich, Switzerland.
| | - Vincent Wirth
- Institute for Molecular Physical Science, ETH Zürich, 8093 Zürich, Switzerland.
| | - Urs Hollenstein
- Institute for Molecular Physical Science, ETH Zürich, 8093 Zürich, Switzerland.
| | - Frédéric Merkt
- Institute for Molecular Physical Science, ETH Zürich, 8093 Zürich, Switzerland.
- Department of Physics, ETH Zürich, 8093 Zürich, Switzerland
- Quantum Center, ETH Zürich, 8093 Zürich, Switzerland
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Bejjani R, Roucou A, Urbain X, Moshkunov K, Vanlancker G, Lauzin C. STARGATE: A new instrument for high-resolution photodissociation spectroscopy of cold ionic species. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:033307. [PMID: 33820109 DOI: 10.1063/5.0039627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Spectroscopy of transient anions and radicals by gated and accelerated time-of-flight experiment is a new spectrometer developed in UCLouvain. This instrument measures high-resolution photodissociation spectra of mass-selected ions by the combination of a time-of-flight spectrometer including a specific gating, bunching, and re-referencing unit with a nanosecond pulsed dye laser, a pulsed deflection, and an energy selector. The ionic species are generated in a supersonic jet expansion by means of an electric discharge or by the impact of electrons coming from an electron gun. The versatility of the molecular systems that can be addressed by this instrument is illustrated by the presentation of mass spectra of cations, anions, and ionic clusters formed from different gas mixtures and backing pressures. The high-resolution spectrum of the A~2Σ+(002)←X~2Π3/2(000) and A~2Σ+(002)←X~2Π1/2(000) rovibronic bands of N2O+ has been measured and analyzed to provide refined molecular parameters in the A~2Σ+(002) upper state. The A~2Σ+(002)←X~2Π3/2(000) band has been used to evaluate the quality of the experimental setup in terms of rotational temperature, time of measurement for certain signal to noise ratio, and the accuracy of the determination of the wavenumber scale.
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Affiliation(s)
- Raghed Bejjani
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve B-1348, Belgium
| | - Anthony Roucou
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve B-1348, Belgium
| | - Xavier Urbain
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve B-1348, Belgium
| | - Konstantin Moshkunov
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve B-1348, Belgium
| | - Guilhem Vanlancker
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve B-1348, Belgium
| | - Clément Lauzin
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Louvain-la-Neuve B-1348, Belgium
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Igosawa R, Hirota A, Kimura N, Kuma S, Chartkunchand KC, Mishra PM, Lindley M, Yamaguchi T, Nakano Y, Azuma T. Photodissociation spectroscopy of N 2O + in the ion storage ring RICE. J Chem Phys 2020; 153:184305. [DOI: 10.1063/5.0027805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- R. Igosawa
- Department of Physics, Saitama University, Saitama 338-8570, Japan
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
| | - A. Hirota
- Department of Physics, Saitama University, Saitama 338-8570, Japan
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
| | - N. Kimura
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
| | - S. Kuma
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
| | - K. C. Chartkunchand
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
| | - P. M. Mishra
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
| | - M. Lindley
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
- Department of Materials and Life Sciences, Sophia University, Tokyo 102-8554, Japan
| | - T. Yamaguchi
- Department of Physics, Saitama University, Saitama 338-8570, Japan
| | - Y. Nakano
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
- Department of Physics, Rikkyo University, Tokyo 171-8501, Japan
| | - T. Azuma
- Atomic, Molecular and Optical Physics Laboratory, RIKEN, Saitama 351-0198, Japan
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