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Inhester L, Oostenrijk B, Patanen M, Kokkonen E, Southworth SH, Bostedt C, Travnikova O, Marchenko T, Son SK, Santra R, Simon M, Young L, Sorensen SL. Chemical Understanding of the Limited Site-Specificity in Molecular Inner-Shell Photofragmentation. J Phys Chem Lett 2018; 9:1156-1163. [PMID: 29444399 DOI: 10.1021/acs.jpclett.7b03235] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In many cases fragmentation of molecules upon inner-shell ionization is very unspecific with respect to the initially localized ionization site. Often this finding is interpreted in terms of an equilibration of internal energy into vibrational degrees of freedom after Auger decay. We investigate the X-ray photofragmentation of ethyl trifluoroacetate upon core electron ionization at environmentally distinct carbon sites using photoelectron-photoion-photoion coincidence measurements and ab initio electronic structure calculations. For all four carbon ionization sites, the Auger decay weakens the same bonds and transfers the two charges to opposite ends of the molecule, which leads to a rapid dissociation into three fragments, followed by further fragmentation steps. The lack of site specificity is attributed to the character of the dicationic electronic states after Auger decay instead of a fast equilibration of internal energy.
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Affiliation(s)
- Ludger Inhester
- Center for Free-Electron Laser Science, DESY , Notkestrasse 85, 22607 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging , Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Bart Oostenrijk
- Department of Physics, Lund University , Box 118, 221 00 Lund, Sweden
| | - Minna Patanen
- Faculty of Science, Nano and Molecular Systems Research Unit, University of Oulu , Box 3000, FIN-90014 Oulu, Finland
| | - Esko Kokkonen
- Faculty of Science, Nano and Molecular Systems Research Unit, University of Oulu , Box 3000, FIN-90014 Oulu, Finland
| | - Stephen H Southworth
- Chemical Sciences and Engineering Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Christoph Bostedt
- Chemical Sciences and Engineering Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States
- Department of Physics, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Oksana Travnikova
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, LCPMR , F-75005 Paris, France
| | - Tatiana Marchenko
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, LCPMR , F-75005 Paris, France
| | - Sang-Kil Son
- Center for Free-Electron Laser Science, DESY , Notkestrasse 85, 22607 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging , Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Robin Santra
- Center for Free-Electron Laser Science, DESY , Notkestrasse 85, 22607 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging , Luruper Chaussee 149, 22761 Hamburg, Germany
- Department of Physics, University of Hamburg , Jungiusstrasse 9, 20355 Hamburg, Germany
| | - Marc Simon
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique - Matière et Rayonnement, LCPMR , F-75005 Paris, France
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States
- Department of Physics and James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - Stacey L Sorensen
- Department of Physics, Lund University , Box 118, 221 00 Lund, Sweden
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Zagorodskikh S, Eland JHD, Zhaunerchyk V, Mucke M, Squibb RJ, Linusson P, Feifel R. Mechanisms of site-specific photochemistry following core-shell ionization of chemically inequivalent carbon atoms in acetaldehyde (ethanal). J Chem Phys 2016; 145:124302. [DOI: 10.1063/1.4962823] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Sergey Zagorodskikh
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
- Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden
| | - John H. D. Eland
- Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Vitali Zhaunerchyk
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
- Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden
| | - Melanie Mucke
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Richard J. Squibb
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
- Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden
| | - Per Linusson
- Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm, Sweden
| | - Raimund Feifel
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
- Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden
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Sakai M, Okada K. Effect of fluoro substitution on the fragmentation of the K-shell excited/ionized pyridine studied by electron impact. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:666-671. [PMID: 21744416 DOI: 10.1002/jms.1936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Fragmentation of the pyridine ring followed by K-shell excitation/ionization has been studied with 2-fluoropyridine (2FPy) by electron impact. Ab initio molecular orbital (MO) calculations were also carried out to investigate the electronic states correlating with specific fragment ions. The fragment ions are produced characteristically at the N 1s edge, while the spectra observed at the F 1s and C 1s edges exhibit a small difference from that at the valence ionization. The production of the C(4)H(2)(+), C(4)H(3)(+) and C(4)H(2)F(+) ions indicates that the cleavage of the N-C6 and C2-C3 bonds or the N-C2 and C5-C6 bonds is likely to occur after the N 1s excitation/ionization. Ab initio MO calculations indicate that the former fission is likely to proceed through the n(N)(1)π(2)(1)π(3)(2) and n(N)(0)π(2)(2)π(3)(2) excited states of the parent molecular dication. On the other hand, the breakage of the N-C2 and C4-C5 bonds, which specifically proceeds at the N 1s edge for 2-methylpyridine, does not occur for 2FPy. The present calculation reveals that the products of this channel are unstable by the electronegativity of fluorine and that the relative energy of the Auger-final states of 2FPy is lowered by the reorganization and electron correlation effects.
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Affiliation(s)
- Masamichi Sakai
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
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Sakai M, Okada K, Ohno K, Tabayashi K. Specific fragmentation of the K-shell excited/ionized pyridine derivatives studied by electron impact: 2-, 3- and 4-methylpyridine. JOURNAL OF MASS SPECTROMETRY : JMS 2010; 45:306-312. [PMID: 20166104 DOI: 10.1002/jms.1717] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fragmentation of the pyridine ring upon K-shell excitation/ionization has been studied with gaseous 2-, 3- and 4-methylpyridine by the electron-impact method. Ab initio molecular orbital (MO) calculations were also carried out to explore electronic states correlating with specific fragments. Some specific fragmentation channels were identified from the ionic fragments enhanced characteristically at the N 1s edge. Yields of the C(2)HN(+) and C(5)H(5)(+)/C(5)H(6)(+) ions show that the fission of the N-C2 and C4-C5/C5-C6 bonds of the ring is likely to occur after the N 1s excitation and ionization. Ab initio MO calculations for the 2-methylpyridine molecule indicate that the dissociation channels to produce these ions are only accessible through the excited states of the parent molecular dication, which can be formed by Auger decays after the N 1s ionization. Fragment ions via hydrogen rearrangement are produced as well, but the rearrangement is not a phenomenon specific to the K-shell excitation/ionization.
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Affiliation(s)
- Masamichi Sakai
- Department of Chemistry, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
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Suzuki IH, Nitta A, Fukuzawa H, Ueda K, Takahashi O, Tamenori Y, Nagaoka S. Site-specific behavior in de-excitation spectra of F(3)SiCH(2)CH(2)Si(CH(3))(3) in the Si 1s excitation region. J Chem Phys 2009; 131:164309. [PMID: 19894949 DOI: 10.1063/1.3257639] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Excitation (total ion yield) and de-excitation (resonant photoemission) spectra have been measured in the Si 1s photoexcitation region of the F(3)SiCH(2)CH(2)Si(CH(3))(3) molecule using monochromatized undulator radiation. Theoretical calculations within the framework of density functional theory have reproduced the observed total ion yield spectrum very well. The first peak at the lowest photon energy, coming from Si 1s excitation at the trimethyl side into a vacant orbital, induces spectator Auger decays in which the excited electron remains in its valence orbital. The second peak produced through excitation of Si 1s electron at the trifluoride side generates resonant Auger decays in which the excited valence electron remains predominantly also in the valence orbital or is partly shaken up into higher Rydberg orbitals. The third peak generated through Si 1s excitation at the trifluoride side produces resonant Auger decays in which the excited Rydberg electron remains or is partly shaken down to a lower lying valence molecular orbital. These findings exhibit a clear distinction between resonant Auger decays following photoexcitation of Si 1s electrons under different chemical environments.
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Affiliation(s)
- I H Suzuki
- Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801, Japan.
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Fukuzawa H, Prümper G, Liu X, Kukk E, Sankari R, Hoshino M, Tanaka H, Tamenori Y, Ueda K. Site-selective ion pair production via normal Auger decay of free CH3F molecules studied by electron–ion–ion coincidence spectroscopy. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.01.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fukuzawa H, Prümper G, Nagaoka SI, Ibuki T, Tamenori Y, Harries J, Liu X, Ueda K. Site-specific fragmentation following F 1s photoionization of free CF3SF5 molecules studied by electron–ion coincidence spectroscopy. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.09.099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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