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van der Burgt PJM, Gradziel ML. Coincidence mass spectrometry study of double ionization of pyrene by 70 eV electron impact. Phys Chem Chem Phys 2024; 26:10688-10697. [PMID: 38511630 DOI: 10.1039/d4cp00443d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
We have performed coincidence mass spectrometry of fragmentation of pyrene molecules by 70 eV electron impact. Ionized fragments have been mass selected using a reflectron time-of-flight mass spectrometer, and a field programmable gate array has been used for the timing of the electron and ion extraction pulses and for the event-by-event detection of the ions. Double ionization results in a number of prominent fragmentations producing two singly-ionized fragments with kinetic energies of up to a few eV. A number of fragmentations produce ions with four or more carbon atoms, which can only be formed by the breaking of at least three C-C bonds.
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Affiliation(s)
- Peter J M van der Burgt
- Department of Experimental Physics, National University of Ireland Maynooth, Maynooth, Co, Kildare, Ireland.
| | - Marcin L Gradziel
- Department of Experimental Physics, National University of Ireland Maynooth, Maynooth, Co, Kildare, Ireland.
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2
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Rapacioli M, Buey MY, Spiegelman F. Addressing electronic and dynamical evolution of molecules and molecular clusters: DFTB simulations of energy relaxation in polycyclic aromatic hydrocarbons. Phys Chem Chem Phys 2024; 26:1499-1515. [PMID: 37933901 PMCID: PMC10793726 DOI: 10.1039/d3cp02852f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
We present a review of the capabilities of the density functional based Tight Binding (DFTB) scheme to address the electronic relaxation and dynamical evolution of molecules and molecular clusters following energy deposition via either collision or photoabsorption. The basics and extensions of DFTB for addressing these systems and in particular their electronic states and their dynamical evolution are reviewed. Applications to PAH molecules and clusters, carbonaceous systems of major interest in astrochemical/astrophysical context, are reported. A variety of processes are examined and discussed such as collisional hydrogenation, fast collisional processes and induced electronic and charge dynamics, collision-induced fragmentation, photo-induced fragmentation, relaxation in high electronic states, electronic-to-vibrational energy conversion and statistical versus non-statistical fragmentation. This review illustrates how simulations may help to unravel different relaxation mechanisms depending on various factors such as the system size, specific electronic structure or excitation conditions, in close connection with experiments.
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Affiliation(s)
- Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantique (LCPQ/FERMI), UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France.
| | - Maysa Yusef Buey
- Laboratoire de Chimie et Physique Quantique (LCPQ/FERMI), UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France.
| | - Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantique (LCPQ/FERMI), UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France.
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3
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Zinck N, Bodi A, Mayer PM. VUV photoprocessing of oxygen-containing polycyclic aromatic hydrocarbons: iPEPICO study of the unimolecular dissociation of ionized benzofuran. CAN J CHEM 2022. [DOI: 10.1139/cjc-2022-0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxygen-containing polycyclic aromatic hydrocarbons (OPAHs) are potential contributors to the 11.3 m band in interstellar observations. To further explore their role in the interstellar medium, we have investigated their fate after photoprocessing by VUV radiation; in particular, we studied the dissociative photoionization of the simplest OPAH, benzofuran, with imaging photoelectron photoion coincidence spectroscopy, iPEPICO. Ionized benzofuran dissociates by loss of CO, followed by a sequential H atom loss. The parallel HCO-loss channel, leading to the same bicyclic C7H5+ fragment ion, is not competitive at low excess energies above the ionization threshold. However, the collision-induced dissociation tandem mass spectrometry results suggest that CO and HCO may be formed in parallel at higher energies. An RRKM fragmentation model reproduced the iPEPICO data well assuming the initial 1,2-H shift transition state to be rate determining to CO loss. The breakdown diagram and the measured dissociation rates agreed well at the CBS-QB3-calculated activation energy of 2.99 eV, which could be relaxed to 3.25 eV, and only a slight adjustment of the ab initio activation entropy. The model barrier to sequential H-loss is larger than the computed H-loss threshold and the breakdown diagram rises less steeply than predicted, which indicates suprastatistical kinetic energy release after the tight H-transfer transition state of the first step. HCO cleavage is possible after a ring-opening transition state, which is looser than and isoenergetic with the CO-loss transition state. However, a subsequent ring formation transition state at 3.85 eV is moderately tight, which suppresses HCO loss at low excess energies.
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Affiliation(s)
- Nicholas Zinck
- University of Ottawa, 6363, Chemistry and Biomolecular Sciences, Ottawa, Ontario, Canada
| | - Andras Bodi
- Paul Scherrer Institut PSI, 28498, Laboratory for Synchrotron Radiation and Femtochemistry, Villigen, Aargau, Switzerland
| | - Paul M Mayer
- University of Ottawa, 6363, Chemistry and Biomolecular Sciences, Ottawa, Ontario, Canada,
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4
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Gatchell M, Ameixa J, Ji M, Stockett MH, Simonsson A, Denifl S, Cederquist H, Schmidt HT, Zettergren H. Survival of polycyclic aromatic hydrocarbon knockout fragments in the interstellar medium. Nat Commun 2021; 12:6646. [PMID: 34789760 PMCID: PMC8599666 DOI: 10.1038/s41467-021-26899-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/28/2021] [Indexed: 11/26/2022] Open
Abstract
Laboratory studies play a crucial role in understanding the chemical nature of the interstellar medium (ISM), but the disconnect between experimental timescales and the timescales of reactions in space can make a direct comparison between observations, laboratory, and model results difficult. Here we study the survival of reactive fragments of the polycyclic aromatic hydrocarbon (PAH) coronene, where individual C atoms have been knocked out of the molecules in hard collisions with He atoms at stellar wind and supernova shockwave velocities. Ionic fragments are stored in the DESIREE cryogenic ion-beam storage ring where we investigate their decay for up to one second. After 10 ms the initially hot stored ions have cooled enough so that spontaneous dissociation no longer takes place at a measurable rate; a majority of the fragments remain intact and will continue to do so indefinitely in isolation. Our findings show that defective PAHs formed in energetic collisions with heavy particles may survive at thermal equilibrium in the interstellar medium indefinitely, and could play an important role in the chemistry in there, due to their increased reactivity compared to intact or photo-fragmented PAHs.
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Affiliation(s)
- Michael Gatchell
- Department of Physics, Stockholm University, 106 91, Stockholm, Sweden.
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020, Innsbruck, Austria.
| | - João Ameixa
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020, Innsbruck, Austria
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal
| | - MingChao Ji
- Department of Physics, Stockholm University, 106 91, Stockholm, Sweden
| | - Mark H Stockett
- Department of Physics, Stockholm University, 106 91, Stockholm, Sweden
| | - Ansgar Simonsson
- Department of Physics, Stockholm University, 106 91, Stockholm, Sweden
| | - Stephan Denifl
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020, Innsbruck, Austria
| | - Henrik Cederquist
- Department of Physics, Stockholm University, 106 91, Stockholm, Sweden
| | - Henning T Schmidt
- Department of Physics, Stockholm University, 106 91, Stockholm, Sweden
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5
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Giacomozzi L, Kjær C, Brøndsted Nielsen S, Ashworth EK, Bull JN, Stockett MH. Non-statistical fragmentation in photo-activated flavin mononucleotide anions. J Chem Phys 2021; 155:044305. [PMID: 34340366 DOI: 10.1063/5.0056415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The spectroscopy and photo-induced dissociation of flavin mononucleotide anions in vacuo are investigated over the 300-500 nm wavelength range. Comparison of the dependence of fragment ion yields as a function of deposited photon energy with calculated dissociation energies and collision-induced dissociation measurements performed under single-collision conditions suggests that a substantial fraction of photo-activated ions decompose through non-statistical fragmentation pathways. Among these pathways is the dominant photo-induced fragmentation channel, the loss of a fragment identified as formylmethylflavin. The fragment ion specific action spectra reveal electronic transition energies close to those for flavins in solution and previously published gas-phase measurements, although the photo-fragment yield upon excitation of the S2 ← S0 transition appears to be suppressed.
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Affiliation(s)
| | - Christina Kjær
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | | | - Eleanor K Ashworth
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - James N Bull
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Mark H Stockett
- Department of Physics, Stockholm University, Stockholm, Sweden
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Stockett MH, Bull JN, Buntine JT, Carrascosa E, Ji M, Kono N, Schmidt HT, Zettergren H. Unimolecular fragmentation and radiative cooling of isolated PAH ions: A quantitative study. J Chem Phys 2020; 153:154303. [PMID: 33092387 DOI: 10.1063/5.0027773] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Time-resolved spontaneous and laser-induced unimolecular fragmentation of perylene cations (C20H12 +) has been measured on timescales up to 2 s in a cryogenic electrostatic ion beam storage ring. We elaborate a quantitative model, which includes fragmentation in competition with radiative cooling via both vibrational and electronic (recurrent fluorescence) de-excitation. Excellent agreement with experimental results is found when sequential fragmentation of daughter ions co-stored with the parent perylene ions is included in the model. Based on the comparison of the model to experiment, we constrain the oscillator strength of the D1 → D0 emissive electronic transition in perylene (fRF = 0.055 ± 0.011), as well as the absolute absorption cross section of the D5 ← D0 excitation transition (σabs > 670 Mb). The former transition is responsible for the laser-induced and recurrent fluorescence of perylene, and the latter is the most prominent in the absorption spectrum. The vibrational cooling rate is found to be consistent with the simple harmonic cascade approximation. Quantitative experimental benchmarks of unimolecular processes in polycyclic aromatic hydrocarbon ions like perylene are important for refining astrochemical models.
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Affiliation(s)
- Mark H Stockett
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - James N Bull
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Jack T Buntine
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Eduardo Carrascosa
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - MingChao Ji
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Naoko Kono
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Henning T Schmidt
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
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7
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Zhang L, Jaroniec M. Strategies for development of nanoporous materials with 2D building units. Chem Soc Rev 2020; 49:6039-6055. [PMID: 32692344 DOI: 10.1039/d0cs00185f] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
It has already been realized that two-dimensional (2D) materials carry a great potential in energy conversion and storage, gas storage, chemical sensing, and many other applications closely related to human life. These applications benefit from a key feature of 2D materials, namely the large specific surface area, which however can be diminished significantly due to the tendency of these materials to restack. In this review, we revisit the strategies - including soft and hard templating - that have been developed for generating nanoporosity in 3D materials and demonstrate their adaptation for 2D materials using carbon nitride and graphene materials as examples. Owing to the 2D nature of the building units, a new type of nanopore can be generated by perforating the basal planes. These in-plane nanopores are essential in many emerging applications of 2D materials such as semipermeable membranes; hence, their creation methods, including post-synthesis activation, ion bombardment, electron beam drilling, and nanolithography, are worthy of a critical review. Lastly, techniques for preventing the restacking by fabricating 2D-0D, 2D-1D, and 2D-2D layer-by-layer composite structures are discussed. The goal is to promote the use of these methods for creating nanoporosity in more 2D materials.
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Affiliation(s)
- Liping Zhang
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, USA.
| | - Mietek Jaroniec
- Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio 44242, USA.
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8
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Giacomozzi L, D’Angelo G, Diaz-Tendero S, de Ruette N, Stockett MH, Alcamí M, Cederquist H, Schmidt HT, Zettergren H. Decay pathways for protonated and deprotonated adenine molecules. J Chem Phys 2019; 151:044306. [DOI: 10.1063/1.5109963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- L. Giacomozzi
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - G. D’Angelo
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - S. Diaz-Tendero
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - N. de Ruette
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - M. H. Stockett
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - M. Alcamí
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-NANO), 28049 Madrid, Spain
| | - H. Cederquist
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - H. T. Schmidt
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - H. Zettergren
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
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9
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West BJ, Lesniak L, Mayer PM. Why Do Large Ionized Polycyclic Aromatic Hydrocarbons Not Lose C2H2? J Phys Chem A 2019; 123:3569-3574. [DOI: 10.1021/acs.jpca.9b01879] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brandi J. West
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada K1N 6N5
| | - Lukas Lesniak
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada K1N 6N5
| | - Paul M. Mayer
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada K1N 6N5
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10
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Rapacioli M, Cazaux S, Foley N, Simon A, Hoekstra R, Schlathölter T. Atomic hydrogen interactions with gas-phase coronene cations: hydrogenation versus fragmentation. Phys Chem Chem Phys 2018; 20:22427-22438. [PMID: 29947389 DOI: 10.1039/c8cp03024c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sequential hydrogenation of polycyclic aromatic hydrocarbon (PAH) cations drives a gradual transition from a planar to a puckered geometry and from an aromatic to an aliphatic electronic structure. The resulting H-induced weakening of the molecular structure together with the exothermic nature of the consecutive H-attachment processes can lead to substantial molecular fragmentation. We have studied H attachment to gas-phase coronene cations in a radiofrequency ion trap using tandem mass spectrometry. With increasing hydrogenation, C2Hi loss and multifragmentation are identified as main de-excitation channels. To understand the dependence of both channels on H-exposure time, we have simulated the molecular stability and fragmentation channels of hydrogenated PAHs using a molecular dynamics approach employing potential energies determined by a density functional based tight binding method. As the coronene fragmentation patterns depend on the balance between energy deposition by H-attachment and the extent of cooling in between subsequent attachment processes, we investigate several scenarios for the energy distribution of hydrogenated PAHs. Good agreement between experiment and simulation is reached, when realistic energy distributions are considered.
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Affiliation(s)
- Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
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11
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Dissociation of polycyclic aromatic hydrocarbons at high energy: MD/DFTB simulations versus collision experiments. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2287-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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de Ruette N, Wolf M, Giacomozzi L, Alexander JD, Gatchell M, Stockett MH, Haag N, Zettergren H, Schmidt HT, Cederquist H. DESIREE electrospray ion source test bench and setup for collision induced dissociation experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:075102. [PMID: 30068131 DOI: 10.1063/1.5030528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this paper, we give a detailed description of an electrospray ion source test bench and a single-pass setup for ion fragmentation studies at the Double ElectroStatic Ion Ring ExpEriment infrastructure at Stockholm University. This arrangement allows for collision-induced dissociation experiments at the center-of-mass energies between 10 eV and 1 keV. Charged fragments are analyzed with respect to their kinetic energies (masses) by means of an electrostatic energy analyzer with a wide angular acceptance and adjustable energy resolution.
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Affiliation(s)
- N de Ruette
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - M Wolf
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - L Giacomozzi
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - J D Alexander
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - M Gatchell
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - M H Stockett
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - N Haag
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - H Zettergren
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - H T Schmidt
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
| | - H Cederquist
- Department of Physics, Stockholm University, Stockholm SE-106 91, Sweden
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Giacomozzi L, Gatchell M, de Ruette N, Wolf M, D'Angelo G, Schmidt HT, Cederquist H, Zettergren H. Knockout driven fragmentation of porphyrins. Phys Chem Chem Phys 2017. [DOI: 10.1039/c7cp01583f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have studied collisions between tetraphenylporphyrin cations and He or Ne at center-of-mass energies in the range 50–110 eV.
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Affiliation(s)
| | | | | | - Michael Wolf
- Department of Physics
- Stockholm University
- Stockholm
- Sweden
| | - Giovanna D'Angelo
- Department of Physics
- Stockholm University
- Stockholm
- Sweden
- Faculdade de Ciências
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14
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PHOTO-STABILITY OF SUPER-HYDROGENATED PAHs DETERMINED BY ACTION SPECTROSCOPY EXPERIMENTS. ACTA ACUST UNITED AC 2016. [DOI: 10.3847/0004-637x/832/1/24] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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