1
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Pihlava L, Berholts M, Niskanen J, Vladyka A, Kooser K, Stråhlman C, Eng-Johnsson P, Kivimäki A, Kukk E. Photodissociation of bromine-substituted nitroimidazole radiosensitizers. Phys Chem Chem Phys 2023; 25:13004-13011. [PMID: 37165880 DOI: 10.1039/d2cp04888d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Heavy elements and some nitroimidazoles both exhibit radiosensitizing properties through different mechanisms. In an effort to see how the overall radiosensitivity might be affected when the two radiosensitizers are combined in the same molecule, we studied the gas-phase photodissociation of two brominated nitroimidazoles and a bromine-free reference sample. Synchrotron radiation was employed to initiate the photodynamics and energy-resolved multiparticle coincidence spectroscopy was used to study the ensuing dissociation. We observed the brominated samples releasing high amounts of potentially radiosensitizing fragments upon dissociation. Since bromination also increases the likelihood of the drug molecule being ionised per a given X-ray dose, we conclude that heavy-element substitution of nitroimidazoles appears to be a viable path towards new, potent radiosensitizer drugs.
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Affiliation(s)
- Lassi Pihlava
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland.
| | - Marta Berholts
- Institute of Physics, University of Tartu, EE-50411 Tartu, Estonia
| | - Johannes Niskanen
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland.
| | - Anton Vladyka
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland.
| | - Kuno Kooser
- Institute of Physics, University of Tartu, EE-50411 Tartu, Estonia
| | - Christian Stråhlman
- Department of Materials Science and Applied Mathematics, Malmö University, SE-20506 Malmö, Sweden
| | | | - Antti Kivimäki
- MAX IV Laboratory, Lund University, SE-20100 Lund, Sweden
| | - Edwin Kukk
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland.
- Laboratoire de Chimie Physique-Matière et Rayonnement, UMR 7614, CNRS, Sorbonne University, FR-75005 Paris, France
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2
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Bolognesi P, Avaldi L. Photoelectron-photoion(s) coincidence studies of molecules of biological interest. Phys Chem Chem Phys 2022; 24:22356-22370. [PMID: 36124990 DOI: 10.1039/d2cp03079a] [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
Photoelectron-photoion(s) coincidence, PEPICO, experiments with synchrotron radiation have become one of the most powerful tools to investigate dissociative photoionization thanks to their selectivity. In this paper their application to the study of molecular species of biological interest in the gas phase is reviewed. Some applications of PEPICO to the study of potential radiosensitizers, amino acids and small peptides and opportunities offered by the advent of novel methods for the production of beams of these molecules are discussed.
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Affiliation(s)
- P Bolognesi
- CNR-Istituto di Struttura della Materia, Area della Ricerca di Roma 1, CP 10 00015 Monterotondo Scalo, Italy.
| | - L Avaldi
- CNR-Istituto di Struttura della Materia, Area della Ricerca di Roma 1, CP 10 00015 Monterotondo Scalo, Italy.
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3
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Gopakumar G, Svensson PHW, Grånäs O, Brena B, Schwob L, Unger I, Saak CM, Timm M, Bülow C, Kubin M, Zamudio-Bayer V, Lau JT, von Issendorff B, Abid AR, Lindblad A, Danielsson E, Koerfer E, Caleman C, Björneholm O, Lindblad R. X-ray Induced Fragmentation of Protonated Cystine. J Phys Chem A 2022; 126:1496-1503. [PMID: 35213156 PMCID: PMC8919253 DOI: 10.1021/acs.jpca.1c10158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We demonstrate site-specific X-ray induced fragmentation across the sulfur L-edge of protonated cystine, the dimer of the amino acid cysteine. Ion yield NEXAFS were performed in the gas phase using electrospray ionization (ESI) in combination with an ion trap. The interpretation of the sulfur L-edge NEXAFS spectrum is supported by Restricted Open-Shell Configuration Interaction (ROCIS) calculations. The fragmentation pathway of triply charged cystine ions was modeled by Molecular Dynamics (MD) simulations. We have deduced a possible pathway of fragmentation upon excitation and ionization of S 2p electrons. The disulfide bridge breaks for resonant excitation at lower photon energies but remains intact upon higher energy resonant excitation and upon ionization of S 2p. The larger fragments initially formed subsequently break into smaller fragments.
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Affiliation(s)
- Geethanjali Gopakumar
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Pamela H W Svensson
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Oscar Grånäs
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Barbara Brena
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Lucas Schwob
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, DE-22607 Hamburg, Germany
| | - Isaak Unger
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Clara-Magdalena Saak
- Department of Physical Chemistry, University of Vienna, Währingerstraßze 42, 1090 Vienna, Austria
| | - Martin Timm
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, DE-12489 Berlin, Germany.,Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, DE-10623 Berlin, Germany
| | - Christine Bülow
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, DE-12489 Berlin, Germany.,Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, DE-79104 Freiburg, Germany
| | - Markus Kubin
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, DE-12489 Berlin, Germany
| | - Vicente Zamudio-Bayer
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, DE-12489 Berlin, Germany
| | - J Tobias Lau
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, DE-12489 Berlin, Germany.,Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, DE-79104 Freiburg, Germany
| | - Bernd von Issendorff
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, DE-79104 Freiburg, Germany
| | - Abdul R Abid
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.,Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, 90570 Oulu, Finland
| | - Andreas Lindblad
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Emma Danielsson
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Ebba Koerfer
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Carl Caleman
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.,Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, DE-22607 Hamburg, Germany
| | - Olle Björneholm
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Rebecka Lindblad
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.,Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, DE-12489 Berlin, Germany.,Department of Physics, Lund University, Box 118, SE-22100 Lund, Sweden.,Department of Chemistry - Ångström Laboratory, Uppsala University, Box 538, SE-75121 Uppsala, Sweden
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4
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Hans A, Schmidt P, Küstner-Wetekam C, Trinter F, Deinert S, Bloß D, Viehmann JH, Schaf R, Gerstel M, Saak CM, Buck J, Klumpp S, Hartmann G, Cederbaum LS, Kryzhevoi NV, Knie A. Suppression of X-ray-Induced Radiation Damage to Biomolecules in Aqueous Environments by Immediate Intermolecular Decay of Inner-Shell Vacancies. J Phys Chem Lett 2021; 12:7146-7150. [PMID: 34297572 DOI: 10.1021/acs.jpclett.1c01879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The predominant reason for the damaging power of high-energy radiation is multiple ionization of a molecule, either direct or via the decay of highly excited intermediates, as, e.g., in the case of X-ray irradiation. Consequently, the molecule is irreparably damaged by the subsequent fragmentation in a Coulomb explosion. In an aqueous environment, however, it has been observed that irradiated molecules may be saved from fragmentation presumably by charge and energy dissipation mechanisms. Here, we show that the protective effect of the environment sets in even earlier than hitherto expected, namely immediately after single inner-shell ionization. By combining coincidence measurements of the fragmentation of X-ray-irradiated microsolvated pyrimidine molecules with theoretical calculations, we identify direct intermolecular electronic decay as the protective mechanism, outrunning the usually dominant Auger decay. Our results demonstrate that such processes play a key role in charge delocalization and have to be considered in investigations and models on high-energy radiation damage in realistic environments.
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Affiliation(s)
- Andreas Hans
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Philipp Schmidt
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Catmarna Küstner-Wetekam
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Florian Trinter
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4, 14195 Berlin, Germany
| | - Sascha Deinert
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Dana Bloß
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Johannes H Viehmann
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Rebecca Schaf
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Miriam Gerstel
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Clara M Saak
- Molecular and Condensed Matter Physics Division, Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - Jens Buck
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Stephan Klumpp
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Gregor Hartmann
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
- Helmholtz-Zentrum Berlin (HZB), Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Lorenz S Cederbaum
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
| | - Nikolai V Kryzhevoi
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
| | - André Knie
- Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
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5
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The reactivity of methanimine radical cation (H2CNH+) and its isomer aminomethylene (HCNH2+) with methane. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138611] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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6
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Mendes M, Kossoski F, Lozano AI, Pereira-da-Silva J, Rodrigues R, Ameixa J, Jones NC, Hoffmann SV, Ferreira da Silva F. Excited States of Bromopyrimidines Probed by VUV Photoabsorption Spectroscopy and Theoretical Calculations. Int J Mol Sci 2021; 22:6460. [PMID: 34208711 PMCID: PMC8235550 DOI: 10.3390/ijms22126460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/10/2021] [Accepted: 06/12/2021] [Indexed: 11/16/2022] Open
Abstract
We report absolute photoabsorption cross sections for gas-phase 2- and 5-bromopyrimidine in the 3.7-10.8 eV energy range, in a joint theoretical and experimental study. The measurements were carried out using high-resolution vacuum ultraviolet synchrotron radiation, with quantum chemical calculations performed through the nuclear ensemble approach in combination with time-dependent density functional theory, along with additional Franck-Condon Herzberg-Teller calculations for the first absorption band (3.7-4.6 eV). The cross sections of both bromopyrimidines are very similar below 7.3 eV, deviating more substantially from each other at higher energies. In the 7.3-9.0 eV range where the maximum cross-section is found, a single and broad band is observed for 5-bromopyrimidine, while more discernible features appear in the case of 2-bromopyrimidine. Several π* ← π transitions account for the most intense bands, while weaker ones are assigned to transitions involving the nitrogen and bromine lone pairs, the antibonding σ*Br orbital, and the lower-lying Rydberg states. A detailed comparison with the available photo-absorption data of bromobenzene is also reported. We have found significant differences regarding the main absorption band, which is more peaked in bromobenzene, becoming broader and shifting to higher energies in both bromopyrimidines. In addition, there is a significant suppression of vibrational structures and of Rydberg states in the pair of isomers, most noticeably for 2-bromopyrimidine.
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Affiliation(s)
- Mónica Mendes
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - Fábris Kossoski
- Laboratoire de Chimie et Physique Quantiques (UMR 5626), Université de Toulouse, CNRS, UPS, CEDEX 09, 31062 Toulouse, France
| | - Ana I. Lozano
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - João Pereira-da-Silva
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - Rodrigo Rodrigues
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - João Ameixa
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
| | - Nykola C. Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark; (N.C.J.); (S.V.H.)
| | - Søren V. Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark; (N.C.J.); (S.V.H.)
| | - Filipe Ferreira da Silva
- CEFITEC, Departamento de Física, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (A.I.L.); (J.P.-d.-S.); (R.R.); (J.A.); (F.F.d.S.)
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7
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Casavola AR, Cartoni A, Castrovilli MC, Borocci S, Bolognesi P, Chiarinelli J, Catone D, Avaldi L. VUV Photofragmentation of Chloroiodomethane: The Iso-CH 2I-Cl and Iso-CH 2Cl-I Radical Cation Formation. J Phys Chem A 2020; 124:7491-7499. [PMID: 32786965 PMCID: PMC8010789 DOI: 10.1021/acs.jpca.0c05754] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Dihalomethanes
XCH2Y (X and Y = F, Cl, Br, and I) are a class of compounds
involved in several processes leading to the release of halogen atoms,
ozone consumption, and aerosol particle formation. Neutral dihalomethanes
have been largely studied, but chemical physics properties and processes
involving their radical ions, like the pathways of their decomposition,
have not been completely investigated. In this work the photodissociation
dynamics of the ClCH2I molecule has been explored in the
photon energy range 9–21 eV using both VUV rare gas discharge
lamps and synchrotron radiation. The experiments show that, among
the different fragment ions, CH2I+ and CH2Cl+, which correspond to the Cl- and I-losses,
respectively, play a dominant role. The experimental ionization energy
of ClCH2I and the appearance energies of the CH2I+ and CH2Cl+ ions are in agreement
with the theoretical results obtained at the MP2/CCSD(T) level of
theory. Computational investigations have been also performed to study
the isomerization of geminal [ClCH2I]•+ into the iso-chloroiodomethane isomers: [CH2I–Cl]•+ and [CH2Cl–I]•+.
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Affiliation(s)
- Anna Rita Casavola
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy
| | - Antonella Cartoni
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy.,Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Mattea Carmen Castrovilli
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy
| | - Stefano Borocci
- Department for Innovation in Biological, Agrofood and Forest Systems, University of Tuscia, Viterbo 01100, Italy.,Institute for Biological Systems-CNR (ISB-CNR), Area della Ricerca di Roma 1, Via Salaria, Km 29.500,, 00015 Monterotondo, Italy
| | - Paola Bolognesi
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy
| | - Jacopo Chiarinelli
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy
| | - Daniele Catone
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Tor Vergata, Via del Fosso del Cavaliere, 00133 Rome, Italy
| | - Lorenzo Avaldi
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy
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8
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Satta M, Cartoni A, Catone D, Castrovilli MC, Bolognesi P, Zema N, Avaldi L. The Reaction of Sulfur Dioxide Radical Cation with Hydrogen and its Relevance in Solar Geoengineering Models. Chemphyschem 2020; 21:1146-1156. [PMID: 32203633 DOI: 10.1002/cphc.202000194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/23/2020] [Indexed: 11/06/2022]
Abstract
SO2 has been proposed in solar geoengineering as a precursor of H2 SO4 aerosol, a cooling agent active in the stratosphere to contrast climate change. Atmospheric ionization sources can ionize SO2 into excited states of S O 2 · + , which quickly reacts with trace gases in the stratosphere. In this work we explore the reaction of H 2 D 2 with S O 2 · + excited by tunable synchrotron radiation, leading to H S O 2 + + H ( D S O 2 + + D ), where H contributes to O3 depletion and OH formation. Density Functional Theory and Variational Transition State Theory have been used to investigate the dynamics of the title barrierless and exothermic reaction. The present results suggest that solar geoengineering models should test the reactivity of S O 2 · + with major trace gases in the stratosphere, such as H2 since this is a relevant channel for the OH formation during the nighttime when there is not OH production by sunlight. OH oxides SO2 , triggering the chemical reactions leading to H2 SO4 aerosol.
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Affiliation(s)
- Mauro Satta
- ISMN (CNR) c/o Dipartimento di Chimica Sapienza Universita' di Roma, Pl.e Aldo Moro 5, Roma, Italy
| | - Antonella Cartoni
- Dipartimento di Chimica, Sapienza Universitá di Roma, Pl.e Aldo Moro 5, Roma, Italy
| | - Daniele Catone
- CNR-ISM, Area della Ricerca di Tor Vergata, Via del Fosso del Cavaliere, Roma, Italy
| | | | - Paola Bolognesi
- CNR-ISM, Area della Ricerca di Roma 1, Via Salaria Km 29,300, Monterotondo Scalo (RM), Italy
| | - Nicola Zema
- CNR-ISM, Area della Ricerca di Tor Vergata, Via del Fosso del Cavaliere, Roma, Italy
| | - Lorenzo Avaldi
- CNR-ISM, Area della Ricerca di Roma 1, Via Salaria Km 29,300, Monterotondo Scalo (RM), Italy
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9
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Chiarinelli J, Casavola AR, Castrovilli MC, Bolognesi P, Cartoni A, Wang F, Richter R, Catone D, Tosic S, Marinkovic BP, Avaldi L. Radiation Damage Mechanisms of Chemotherapeutically Active Nitroimidazole Derived Compounds. Front Chem 2019; 7:329. [PMID: 31157205 PMCID: PMC6528692 DOI: 10.3389/fchem.2019.00329] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 04/24/2019] [Indexed: 11/15/2022] Open
Abstract
Photoionization mass spectrometry, photoelectron-photoion coincidence spectroscopic technique, and computational methods have been combined to investigate the fragmentation of two nitroimidazole derived compounds: the metronidazole and misonidazole. These molecules are used in radiotherapy thanks to their capability to sensitize hypoxic tumor cells to radiation by "mimicking" the effects of the presence of oxygen as a damaging agent. Previous investigations of the fragmentation patterns of the nitroimidazole isomers (Bolognesi et al., 2016; Cartoni et al., 2018) have shown their capacity to produce reactive molecular species such as nitric oxide, carbon monoxide or hydrogen cyanide, and their potential impact on the biological system. The results of the present work suggest that different mechanisms are active for the more complex metronidazole and misonidazole molecules. The release of nitric oxide is hampered by the efficient formation of nitrous acid or nitrogen dioxide. Although both metronidazole and misonidazole contain imidazole ring in the backbone, the side branches of these molecules lead to very different bonding mechanisms and properties.
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Affiliation(s)
- Jacopo Chiarinelli
- CNR-Istituto di Struttura Della Materia (CNR-ISM), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
- Dipartimento di Scienze, Università di Roma Tre, Rome, Italy
| | - Anna Rita Casavola
- CNR-Istituto di Struttura Della Materia (CNR-ISM), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
| | - Mattea Carmen Castrovilli
- CNR-Istituto di Struttura Della Materia (CNR-ISM), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
| | - Paola Bolognesi
- CNR-Istituto di Struttura Della Materia (CNR-ISM), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
| | - Antonella Cartoni
- CNR-Istituto di Struttura Della Materia (CNR-ISM), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
- Dipartimento di Chimica, Sapienza Università di Roma, Rome, Italy
| | - Feng Wang
- Molecular Modelling Discovery Laboratory, Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, VIC, Australia
| | - R. Richter
- Elettra-Sincrotrone Trieste, Trieste, Italy
| | - Daniele Catone
- CNR-Istituto di Struttura Della Materia, Area della Ricerca di Tor Vergata, Rome, Italy
| | - Sanja Tosic
- Institute of Physics, Laboratory for Atomic Collision Processes, University of Belgrade, Belgrade, Serbia
| | - Bratislav P. Marinkovic
- Institute of Physics, Laboratory for Atomic Collision Processes, University of Belgrade, Belgrade, Serbia
| | - Lorenzo Avaldi
- CNR-Istituto di Struttura Della Materia (CNR-ISM), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
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10
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Catone D, Satta M, Cartoni A, Castrovilli MC, Bolognesi P, Turchini S, Avaldi L. Gas Phase Oxidation of Carbon Monoxide by Sulfur Dioxide Radical Cation: Reaction Dynamics and Kinetic Trend With the Temperature. Front Chem 2019; 7:140. [PMID: 30972318 PMCID: PMC6443698 DOI: 10.3389/fchem.2019.00140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/25/2019] [Indexed: 01/16/2023] Open
Abstract
Gas phase ion chemistry has fundamental and applicative purposes since it allows the study of the chemical processes in a solvent free environment and represents models for reactions occurring in the space at low and high temperatures. In this work the ion-molecule reaction of sulfur dioxide ion SO 2 . + with carbon monoxide CO is investigated in a joint experimental and theoretical study. The reaction is a fast and exothermic chemical oxidation of CO into more stable CO2 by a metal free species, as SO 2 . + , excited into ro-vibrational levels of the electronic ground state by synchrotron radiation. The results show that the reaction is hampered by the enhancement of internal energy of sulfur dioxide ion and the only ionic product is SO.+. The theoretical approach of variational transition state theory (VTST) based on density functional electronic structure calculations, shows an interesting and peculiar reaction dynamics of the interacting system along the reaction path. Two energy minima corresponding to [SO2-CO].+ and [OS-OCO].+ complexes are identified. These minima are separated by an intersystem crossing barrier which couples the bent 3B2 state of CO2 with C2v symmetry and the 1A1 state with linear D∞h symmetry. The spin and charge reorganization along the minimum energy path (MEP) are analyzed and eventually the charge and spin remain allocated to the SO.+ moiety and the stable CO2 molecule is easily produced. There is no bottleneck that slows down the reaction and the values of the rate coefficient k at different temperatures are calculated with capture theory. A value of 2.95 × 10-10 cm3s-1molecule-1 is obtained at 300 K in agreement with the literature experimental measurement of 3.00 × 10-10 ± 20% cm3s-1molecule-1, and a negative trend with temperature is predicted consistently with the experimental observations.
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Affiliation(s)
- Daniele Catone
- Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR-ISM), Area della Ricerca di Roma Tor Vergata, Rome, Italy
| | - Mauro Satta
- Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), Dipartimento di Chimica, Sapienza Università di Roma, Rome, Italy
| | - Antonella Cartoni
- Dipartimento di Chimica, Sapienza Università di Roma, Rome, Italy.,Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR-ISM), Area della Ricerca di Roma 1, Rome, Italy
| | - Mattea C Castrovilli
- Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR-ISM), Area della Ricerca di Roma 1, Rome, Italy
| | - Paola Bolognesi
- Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR-ISM), Area della Ricerca di Roma 1, Rome, Italy
| | - Stefano Turchini
- Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR-ISM), Area della Ricerca di Roma Tor Vergata, Rome, Italy
| | - Lorenzo Avaldi
- Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR-ISM), Area della Ricerca di Roma 1, Rome, Italy
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11
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Corinti D, Catone D, Turchini S, Rondino F, Crestoni ME, Fornarini S. Photoionization mass spectrometry of ω-phenylalkylamines: Role of radical cation-π interaction. J Chem Phys 2018; 148:164307. [DOI: 10.1063/1.5027786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Davide Corinti
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza,” P.le A. Moro 5, I-00185 Roma, Italy
| | - Daniele Catone
- CNR-ISM, Area della Ricerca di Roma Tor Vergata, Via del Fosso del Cavaliere 100, Roma, Italy
| | - Stefano Turchini
- CNR-ISM, Area della Ricerca di Roma Tor Vergata, Via del Fosso del Cavaliere 100, Roma, Italy
| | - Flaminia Rondino
- C. R. ENEA Frascati, FSN-TECFIS, Via E. Fermi 45, 00044 Frascati, Italy
| | - Maria Elisa Crestoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza,” P.le A. Moro 5, I-00185 Roma, Italy
| | - Simonetta Fornarini
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma “La Sapienza,” P.le A. Moro 5, I-00185 Roma, Italy
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12
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Cartoni A, Casavola AR, Bolognesi P, Castrovilli MC, Catone D, Chiarinelli J, Richter R, Avaldi L. Insights into 2- and 4(5)-Nitroimidazole Decomposition into Relevant Ions and Molecules Induced by VUV Ionization. J Phys Chem A 2018; 122:4031-4041. [DOI: 10.1021/acs.jpca.8b01144] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. Cartoni
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1, via Salaria Km 29,300, Monterotondo Scalo (RM), 00016, Italy
- Dipartimento di Chimica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185, Roma, Italy
| | - A. R. Casavola
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1, via Salaria Km 29,300, Monterotondo Scalo (RM), 00016, Italy
| | - P. Bolognesi
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1, via Salaria Km 29,300, Monterotondo Scalo (RM), 00016, Italy
| | - M. C. Castrovilli
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1, via Salaria Km 29,300, Monterotondo Scalo (RM), 00016, Italy
| | - D. Catone
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 2, via del Fosso del Cavaliere 10, 00133, Roma, Italy
| | - J. Chiarinelli
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1, via Salaria Km 29,300, Monterotondo Scalo (RM), 00016, Italy
| | - R. Richter
- Elettra Sincrotrone Trieste, Area Science
Park, 34149, Basovizza, Trieste, Italy
| | - L. Avaldi
- Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1, via Salaria Km 29,300, Monterotondo Scalo (RM), 00016, Italy
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13
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Castrovilli MC, Bolognesi P, Bodo E, Mattioli G, Cartoni A, Avaldi L. An experimental and theoretical investigation of XPS and NEXAFS of 5-halouracils. Phys Chem Chem Phys 2018; 20:6657-6667. [PMID: 29457179 DOI: 10.1039/c8cp00026c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The C, N and O 1s excitation and ionization processes of 5X-uracil (X = F, Cl, Br, and I) were investigated using near edge X-ray absorption fine structure (NEXAFS) and X-ray photoemission (XPS) spectroscopies. This study aims at the fine assessment of the effects of the functionalization of uracil molecules by halogen atoms having different electronegativity and bound to the same molecular site. Two DFT-based approaches, which rely on different paradigms, have been used to simulate the experimental spectra and to assign the corresponding features. The analysis of the screening of the core holes of the different atoms via electronic charge density plots has turned out to be a useful tool to illustrate the competition between the partially aromatic and partially conjugate properties of this class of molecules.
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Affiliation(s)
- M C Castrovilli
- Istituto di Struttura della Materia-CNR, ISM-CNR, Area della Ricerca di Roma 1, CP10, 00015 Monterotondo Scalo, Italy.
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14
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Wang M, Chen J, Fei WF, Li ZH, Yu YP, Lin X, Shan XB, Liu FY, Sheng LS. Dissociative Photoionization of 1,4-Dioxane with Tunable VUV Synchrotron Radiation. CHINESE J CHEM PHYS 2017. [DOI: 10.1063/1674-0068/30/cjcp1704068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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15
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Rezaee M, Hill RP, Jaffray DA. The Exploitation of Low-Energy Electrons in Cancer Treatment. Radiat Res 2017; 188:123-143. [PMID: 28557630 DOI: 10.1667/rr14727.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Given the distinct characteristics of low-energy electrons (LEEs), particularly at energies less than 30 eV, they can be applied to a wide range of therapeutic modalities to improve cancer treatment. LEEs have been shown to efficiently produce complex molecular damage resulting in substantial cellular toxicities. Since LEEs are produced in copious amounts from high-energy radiation beam, including photons, protons and ions; the control of LEE distribution can potentially enhance the therapeutic radio of such beams. LEEs can play a substantial role in the synergistic effect between radiation and chemotherapy, particularly halogenated and platinum-based anticancer drugs. Radiosensitizing entities containing atoms of high atomic number such as gold nanoparticles can be a source of LEE production if high-energy radiation interacts with them. This can provide a high local density of LEEs in a cell and produce cellular toxicity. Auger-electron-emitting radionuclides also create a high number of LEEs in each decay, which can induce lethal damage in a cell. Exploitation of LEEs in cancer treatment, however, faces a few challenges, such as dosimetry of LEEs and selective delivery of radiosensitizing and chemotherapeutic molecules close to cellular targets. This review first discusses the rationale for utilizing LEEs in cancer treatment by explaining their mechanism of action, describes theoretical and experimental studies at the molecular and cellular levels, then discusses strategies for achieving modification of the distribution and effectiveness of LEEs in cancerous tissue and their associated clinical benefit.
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Affiliation(s)
- Mohammad Rezaee
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Ontario Cancer Institute and Campbell Family Institute for Cancer Research and Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Richard P Hill
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Ontario Cancer Institute and Campbell Family Institute for Cancer Research and Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - David A Jaffray
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Ontario Cancer Institute and Campbell Family Institute for Cancer Research and Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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16
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Cartoni A, Catone D, Bolognesi P, Satta M, Markus P, Avaldi L. HSO2
+
Formation from Ion-Molecule Reactions of SO2
⋅+
with Water and Methane: Two Fast Reactions with Reverse Temperature-Dependent Kinetic Trend. Chemistry 2017; 23:6772-6780. [DOI: 10.1002/chem.201700028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Antonella Cartoni
- Dipartimento di Chimica; Sapienza Università di Roma; Pl.e Aldo Moro 5 00185 Roma Italy
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
| | - Daniele Catone
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 2; via del Fosso del Cavaliere 10 00133 Roma Italy
| | - Paola Bolognesi
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
| | - Mauro Satta
- Istituto per lo Studio dei Materiali Nanostrutturati (ISMN); Dipartimento di Chimica; Sapienza Università di Roma; P.le Aldo Moro 5 00185 Roma Italy
| | - Pal Markus
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
| | - Lorenzo Avaldi
- Istituto di Struttura della Materia (ISM); Consiglio Nazionale delle Ricerche (CNR), Area della Ricerca di Roma 1; via Salaria Km 29,300 Monterotondo Scalo (RM) 00016 Italy
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17
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Castrovilli MC, Markush P, Bolognesi P, Rousseau P, Maclot S, Cartoni A, Delaunay R, Domaracka A, Kočišek J, Huber BA, Avaldi L. Fragmentation of pure and hydrated clusters of 5Br-uracil by low energy carbon ions: observation of hydrated fragments. Phys Chem Chem Phys 2017; 19:19807-19814. [DOI: 10.1039/c7cp02233f] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The fragmentation of the isolated 5-bromouracil (5BrU) molecule and pure and nano-hydrated 5BrU clusters induced by low energy 12C4+ ions has been studied.
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Affiliation(s)
| | | | | | | | - S. Maclot
- Normandie Université
- ENSICAEN
- UNICAEN
- CEA
- CNRS
| | - A. Cartoni
- CNR-ISM
- Monterotondo Scalo
- Italy
- Dipartimento di Chimica
- Sapienza Università di Roma
| | | | | | - J. Kočišek
- Normandie Université
- ENSICAEN
- UNICAEN
- CEA
- CNRS
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18
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Satta M, Bolognesi P, Cartoni A, Casavola AR, Catone D, Markus P, Avaldi L. A joint theoretical and experimental study on diiodomethane: Ions and neutrals in the gas phase. J Chem Phys 2015; 143:244312. [DOI: 10.1063/1.4937425] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mauro Satta
- Dipartimento di Chimica, CNR-ISMN, Sapienza Università di Roma, Roma 00185, Italy
| | - Paola Bolognesi
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo Scalo, RM 00015, Italy
| | - Antonella Cartoni
- Dipartimento di Chimica, Sapienza Università di Roma, Roma 00185, Italy
| | - Anna Rita Casavola
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo Scalo, RM 00015, Italy
| | - Daniele Catone
- CNR-ISM, Area della Ricerca di Roma 2, Roma 00133, Italy
| | - Pal Markus
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo Scalo, RM 00015, Italy
| | - Lorenzo Avaldi
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo Scalo, RM 00015, Italy
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19
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Bolognesi P, Kettunen JA, Cartoni A, Richter R, Tosic S, Maclot S, Rousseau P, Delaunay R, Avaldi L. Site- and state-selected photofragmentation of 2Br-pyrimidine. Phys Chem Chem Phys 2015; 17:24063-9. [PMID: 26314495 DOI: 10.1039/c5cp02601f] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fragmentation of the 2Br-pyrimidine molecule following direct valence photoionization or inner shell excitation has been studied by electron-ion coincidence experiments. 2Br-pyrimidine has been chosen as a model for the class of pyrimidinic building blocks of three nucleic acids and several radiosensitizers. It is known that the site- and state-localization of energy deposition, typical of inner shell excitation, results in the enhancement of the total ion yield as well as in changes in the relative intensity of the different fragmentation channels. Here we address the question of the origin of this selective fragmentation by using electron-ion coincidence techniques. The results show that the fragmentation is strongly selective in the final singly charged ion state, independently of the process that leads to the population of that state, and the dominant fragmentation patterns correlate with the nearest appearance potential.
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Affiliation(s)
- P Bolognesi
- CNR-Istituto di Struttura della Materia, Area della Ricerca di Roma1, Monterotondo Scalo, Italy.
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20
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Cartoni A, Casavola AR, Bolognesi P, Borocci S, Avaldi L. VUV Photofragmentation of CH2I2: The [CH2I–I]•+ Iso-diiodomethane Intermediate in the I-Loss Channel from [CH2I2]•+. J Phys Chem A 2015; 119:3704-9. [DOI: 10.1021/jp511067d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Antonella Cartoni
- Dipartimento
di Chimica, Sapienza Università di Roma, P. le Aldo Moro
5, Rome 00185, Italy
| | - Anna Rita Casavola
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo
Scalo (RM) 00015, Italy
| | - Paola Bolognesi
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo
Scalo (RM) 00015, Italy
| | - Stefano Borocci
- Dipartimento
per l’ Innovazione nei sistemi Biologici, Agroalimentari e
Forestali (DIBAF), Università della Tuscia, L.go dell’Università, s.n.c., 01100 Viterbo, Italy
| | - Lorenzo Avaldi
- CNR-ISM, Area della Ricerca di Roma 1, Monterotondo
Scalo (RM) 00015, Italy
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21
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Cartoni A, Bolognesi P, Fainelli E, Avaldi L. Photofragmentation spectra of halogenated methanes in the VUV photon energy range. J Chem Phys 2014; 140:184307. [PMID: 24832270 DOI: 10.1063/1.4874114] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this paper an investigation of the photofragmentation of dihalomethanes CH2X2 (X = F, Cl, Br, I) and chlorinated methanes (CH(n)Cl(4-n) with n = 0-3) with VUV helium, neon, and argon discharge lamps is reported and the role played by the different halogen atoms is discussed. Halogenated methanes are a class of molecules used in several fields of chemistry and the study of their physical and chemical proprieties is of fundamental interest. In particular their photodissociation and photoionization are of great importance since the decomposition of these compounds in the atmosphere strongly affects the environment. The results of the present work show that the halogen-loss is the predominant fragmentation channel for these molecules in the VUV photon energy range and confirm their role as reservoir of chlorine, bromine, and iodine atoms in the atmosphere. Moreover, the results highlight the peculiar feature of CH2F2 as a source of both fluorine and hydrogen atoms and the characteristic formation of I2(+) and CH2(+) ions from the photofragmentation of the CH2I2 molecule.
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Affiliation(s)
- Antonella Cartoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, P.le Aldo Moro 5, Roma 00185, Italy
| | - Paola Bolognesi
- CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015, Italy
| | - Ettore Fainelli
- CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015, Italy
| | - Lorenzo Avaldi
- CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015, Italy
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