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Selective Generation of the Radical Cation Isomers [CH3CN](center dot+) and [CH2CNH](center dot+) via VUV Photoionization of Different Neutral Precursors and Their Reactivity with C2H4
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SYSNO ASEP 0467081 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Selective Generation of the Radical Cation Isomers [CH3CN](center dot+) and [CH2CNH](center dot+) via VUV Photoionization of Different Neutral Precursors and Their Reactivity with C2H4 Tvůrce(i) Polášek, Miroslav (UFCH-W) RID, ORCID
Zins, E. L. (FR)
Alcaraz, Ch. (FR)
Žabka, Ján (UFCH-W) RID, ORCID, SAI
Křížová, Věra (UFCH-W)
Giacomozzi, L. (IT)
Tosi, P. (IT)
Ascenzi, D. (IT)Zdroj.dok. Journal of Physical Chemistry A. - : American Chemical Society - ISSN 1089-5639
Roč. 120, č. 27 (2016), s. 5041-5052Poč.str. 12 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova COMPLEX ORGANIC-MOLECULES ; MILLIMETER EMISSION-LINES ; TITANS UPPER-ATMOSPHERE Vědní obor RIV CF - Fyzikální chemie a teoretická chemie CEP LD14024 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy GA14-19693S GA ČR - Grantová agentura ČR Institucionální podpora UFCH-W - RVO:61388955 UT WOS 000379988900051 EID SCOPUS 84978630833 DOI 10.1021/acs.jpca.5b12757 Anotace Experimental and theoretical studies have been carried out to demonstrate the selective generation of two different C2H3N center dot+ isomers, namely, the acetonitrile [CH3CN](center dot+) and the ketenimine [CH2CNH](center dot+) radical cations. Photoionization and dissociative photoionization experiments from different neutral precursors (acetonitrile and butanenitrile) have been performed using vacuum ultraviolet (VUV) synchrotron radiation in the 10-15 eV energy range, delivered by the DESIRS beamline at the SOLEIL storage ring. For butanenitrile (CH3CH2CH2CN) an experimental ionization threshold of 11.29 +/- 0.05 eV is obtained, whereas the appearance energy for the formation of [CH2CNH](center dot+) fragments is 11.52 +/- 0.05 eV. Experimental findings are fully supported by theoretical calculations at the G4 level of theory (ZPVE corrected energies at 0 K), giving a value of 11.33 eV for the adiabatic ionization energy of butanenitrile and an exothermicity of 0.49 for fragmentation into [CH2CNH](center dot+) plus C2H4, hampered by an energy barrier of 0.29 eV. The energy difference between [CH3CN](center dot+) and [CH2CNH](center dot+) is 2.28 eV (with the latter being the lowest energy isomer), and the isomerization barrier is 0.84 eV. Reactive monitoring experiments of the [CH3CN](center dot+) and [CH2CNH](center dot+) isomers with C2H4 have been performed using the CERISES guided ion beam tandem mass spectrometer and exploiting the selectivity of ethylene that gives exothermic charge exchange and proton transfer reactions with [CH3CN](center dot+) but not with [CH2CNH](center dot+) isomers. In addition, minor reactive channels are observed leading to the formation of new C-C bonds upon reaction of [CH3CN](center dot+) with C2H4, and their astrochemical implications are briefly discussed. Pracoviště Ústav fyzikální chemie J.Heyrovského Kontakt Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Rok sběru 2017
Počet záznamů: 1