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Bodi A, Knurr J, Ascher P, Hemberger P, Bostedt C, Al Haddad A. VUV absorption spectra of water and nitrous oxide by a double-duty differentially pumped gas filter. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:1257-1263. [PMID: 39042580 PMCID: PMC11371026 DOI: 10.1107/s1600577524005423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 06/06/2024] [Indexed: 07/25/2024]
Abstract
The differentially pumped rare-gas filter at the end of the VUV beamline of the Swiss Light Source has been adapted to house a windowless absorption cell for gases. Absorption spectra can be recorded from 7 eV to up to 21 eV photon energies routinely, as shown by a new water and nitrous oxide absorption spectrum. By and large, the spectra agree with previously published ones both in terms of resonance energies and absorption cross sections, but that of N2O exhibits a small shift in the {\tilde{\bf D}} band and tentative fine structures that have not yet been fully described. This setup will facilitate the measurement of absorption spectra in the VUV above the absorption edge of LiF and MgF2 windows. It will also allow us to carry out condensed-phase measurements on thin liquid sheets and solid films. Further development options are discussed, including the recording of temperature-dependent absorption spectra, a stationary gas cell for calibration measurements, and the improvement of the photon energy resolution.
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Affiliation(s)
- Andras Bodi
- Paul Scherrer Institute5232Villigen-PSISwitzerland
| | - Jonas Knurr
- Paul Scherrer Institute5232Villigen-PSISwitzerland
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Malicka MI, Field RW, Ryzner S, Stasik A, Ubachs W, Heays AN, de Oliveira N, Szajna W, Hakalla R. FT-spectroscopy of the 12C 18O rare isotopologue and deperturbation analysis of the A 1Π(v = 3) level. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 312:124011. [PMID: 38428210 DOI: 10.1016/j.saa.2024.124011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/01/2024] [Accepted: 02/05/2024] [Indexed: 03/03/2024]
Abstract
Research on 12C18O was carried out using two complementary Fourier-transform methods: (1) vacuum-ultraviolet absorption spectroscopy, with an accuracy ca. 0.03 cm-1 on the DESIRS beamline (SOLEIL synchrotron) and (2) visible emission spectroscopy with an accuracy of about 0.005-0.007 cm-1 by means of the Bruker IFS 125HR spectrometer (University of Rzeszów). The maximum rotational quantum number of the energy levels involved in the observed spectral lines was Jmax = 54. An effective Hamiltonian and the term-value fitting approach were implemented for the precise analysis of the A1Π(v = 3) level in 12C18O. It was performed by means of the PGOPHER code. The data set consisted of 571 spectral lines belonging to the A1Π-X1Σ+(3, 0), B1Σ+-A1Π(0, 3), C1Σ+-A1Π(0, 3) bands and several lines involving states that perturb the A1Π(v = 3) level as well as to the previously analysed B1Σ+-X1Σ+(0, 0) and C1Σ+-X1Σ+(0, 0) transitions. A significantly extended quantum-mechanical description of the A1Π(v = 3) level in 12C18O was provided. It consists of the 5 new unimolecular interactions of the spin-orbit and rotation-electronic nature, which had not been taken into account previously in the literature. The ro-vibronic term values of the A1Π(v = 3, Jmax = 55), a'3Σ+(v = 13), D1Δ(v = 4) and I1Σ-(v = 5) levels were determined with precision improved by a factor of 10 relative to the previously known values.
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Affiliation(s)
- M I Malicka
- The Faculty of Mathematics and Applied Physics, Rzeszów University of Technology, Powstańców Warszawy 8 Street, 35-959, Rzeszów, Poland.
| | - R W Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge MA02139, USA
| | - S Ryzner
- Materials Spectroscopy Laboratory, Institute of Physics, University of Rzeszów, Pigonia 1 Street, 35-310 Rzeszów, Poland; Doctoral School of the University of Rzeszów, University of Rzeszów, Rejtana 16C Street, 35-959 Rzeszów, Poland
| | - A Stasik
- Materials Spectroscopy Laboratory, Institute of Physics, University of Rzeszów, Pigonia 1 Street, 35-310 Rzeszów, Poland
| | - W Ubachs
- Department of Physics and Astronomy, and LaserLaB, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, the Netherlands
| | - A N Heays
- J. Heyrovský Institute of Physical Chemistry, Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - N de Oliveira
- Synchrotron SOLEIL, Orme de Merisiers, St. Aubin, BP 48, F-91192 Gif sur Yvette Cedex, France
| | - W Szajna
- Materials Spectroscopy Laboratory, Institute of Physics, University of Rzeszów, Pigonia 1 Street, 35-310 Rzeszów, Poland
| | - R Hakalla
- Materials Spectroscopy Laboratory, Institute of Physics, University of Rzeszów, Pigonia 1 Street, 35-310 Rzeszów, Poland
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Chang Y, Ashfold MNR, Yuan K, Yang X. Exploring the vacuum ultraviolet photochemistry of astrochemically important triatomic molecules. Natl Sci Rev 2023; 10:nwad158. [PMID: 37771464 PMCID: PMC10533343 DOI: 10.1093/nsr/nwad158] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/03/2022] [Accepted: 02/08/2023] [Indexed: 09/30/2023] Open
Abstract
The recently constructed vacuum ultraviolet (VUV) free electron laser (FEL) at the Dalian Coherent Light Source (DCLS) is yielding a wealth of new and exquisitely detailed information about the photofragmentation dynamics of many small gas-phase molecules. This Review focuses particular attention on five triatomic molecules-H2O, H2S, CO2, OCS and CS2. Each shows excitation wavelength-dependent dissociation dynamics, yielding photofragments that populate a range of electronic and (in the case of diatomic fragments) vibrational and rotational quantum states, which can be characterized by different translational spectroscopy methods. The photodissociation of an isolated molecule from a well-defined initial quantum state provides a lens through which one can investigate how and why chemical reactions occur, and provides numerous opportunities for fruitful, synergistic collaborations with high-level ab initio quantum chemists. The chosen molecules, their photofragments and the subsequent chemical reaction networks to which they can contribute are all crucial in planetary atmospheres and in interstellar and circumstellar environments. The aims of this Review are 3-fold: to highlight new photochemical insights enabled by the VUV-FEL at the DCLS, notably the recently recognized central atom elimination process that is shown to contribute in all of these triatomic molecules; to highlight some of the potential implications of this rich photochemistry to our understanding of interstellar chemistry and molecular evolution within the universe; and to highlight other and future research directions in areas related to chemical reaction dynamics and astrochemistry that will be enabled by increased access to VUV-FEL sources.
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Affiliation(s)
- Yao Chang
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | | | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Hefei National Laboratory, Hefei 230088, China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Hefei National Laboratory, Hefei 230088, China
- Department of Chemistry, College of Science, Southern University of Science and Technology, Shenzhen 518055, China
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Yin T, Ma L, Cheng M, Gao H. A New Band System of the Dicarbon Molecule in the Vacuum Ultraviolet Region. J Phys Chem Lett 2022; 13:11008-11014. [PMID: 36410726 DOI: 10.1021/acs.jpclett.2c03175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
As one of the most abundant molecules in the universe, the long history of spectroscopic studies of the dicarbon molecule, C2, reaches back two centuries. While many electronic band systems with upper states below the lowest dissociation threshold have been well characterized, much less is known about transitions to higher-lying states. Here, we report the observation of a new band system of C2 from the lowest triplet state a3Πu through a resonance-enhanced multiphoton ionization scheme. The upper state is identified as 13Σg+, which is determined to be 61539.0 cm-1 (7.630 eV) above ground state X1Σg+. The spectroscopic parameters determined for the 13Σg+ state are in excellent agreement with those predicted by the high-level ab initio calculations. This study paves the way for systematic investigations of the photoabsorption and photodissociation of C2 in the vacuum ultraviolet region, which has important applications in the field of astrochemistry.
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Affiliation(s)
- Tonghui Yin
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liying Ma
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Cheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong Gao
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Liu M, Jiang P, Cheng M, Gao H. Vacuum ultraviolet photoexcitation and photofragment spectroscopic studies of 14N 15N between 109000 and 117500 cm -1. J Chem Phys 2021; 155:234305. [PMID: 34937384 DOI: 10.1063/5.0072604] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this study, we employed a newly built time-slice velocity-map ion imaging setup, equipped with two tunable vacuum ultraviolet (VUV) laser sources, to obtain the first comprehensive high-resolution photoexcitation and photofragment excitation spectra of 14N15N in the VUV photon energy range 109 000-117 500 cm-1. The spectroscopic simulation program PGOPHER was used to analyze the rotationally resolved spectra. Band origins, rotational constants, and isotope shifts compared with those of 14N2 have been obtained for 31 electric-dipole-allowed vibrational states of 14N15N in the aforementioned energy range. These spectroscopic parameters are found to depend on the vibrational quantum number irregularly. Systematic perturbations of the rotational transition energies and predissociation rates within individual absorption bands have also been observed. These are proved to be caused by the strong homogeneous interactions between the valence b'1Σu + state and the Rydberg cn ' 1Σu + states, and between the valence b1Πu states and the Rydberg o3 1Πu states. Heterogeneous interactions between the Rydberg cn 1Πu states and cn ' 1Σu + states also play an important role.
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Affiliation(s)
- Min Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Pan Jiang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Min Cheng
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hong Gao
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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