title: Stripping off hydrogens in imidazole triggered by the attachment of a single electron.
abstract: Imidazole [C3H4N2] is ubiquitous in nature as an important biological building block of amino acids, purine nucleobases or antibiotics. In the present study, dissociative electron attachment to imidazole shows low energy shape resonances at 1.52 and 2.29 eV leading to the most abundant dehydrogenated anion [imidazole - H]-through dehydrogenation at the N1 position. All the other anions formed exhibit core excited resonances observed dominantly at similar electron energies of ∼7 and 11 eV, suggesting an initial formation through two temporary negative ion states. Among these anions, multiple dehydrogenation reactions are observed resulting in the loss of 2 up to 4 hydrogens, thus, leading to a complete dehydrogenation of the imidazole molecule, an interesting prototype of complex unimolecular decay induced by the attachment of a single electron. Additionally, the quantum chemical calculations reveal that these multiple dehydrogenation reactions are responsible for the remarkable one electron-induced gas-phase chemistry leading to the opening of the ring. The formation of the observed anions is likely driven by the high positive electron affinity of cyanocarbon molecules supported by quantum chemical calculations. The formation of H-showed additional resonance at about 5 eV and dipolar dissociation above ∼14 eV.
authors.affiliation: Institut für Ionenphysik und Angewandte Physik and Center for Molecular Biosciences Innsbruck (CMBI), Leopold Franzens Universität Innsbruck, Technikerstrasse 25, A-6020, Austria. Linda.Feketeova@uibk.ac.at Stephan.Denifl@uibk.ac.at and Department of Plasma Physics, Comenius University, Mlynská dolina F2, 84248 Bratislava, Slovakia.
authors.forename: A
authors.initials: A
authors.lastname: Ribar
authors.affiliation: Institut für Ionenphysik und Angewandte Physik and Center for Molecular Biosciences Innsbruck (CMBI), Leopold Franzens Universität Innsbruck, Technikerstrasse 25, A-6020, Austria. Linda.Feketeova@uibk.ac.at Stephan.Denifl@uibk.ac.at.
authors.forename: K
authors.initials: K
authors.lastname: Fink
authors.affiliation: Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA and Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.affiliation: Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA and Department of Physics, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ptasińska
authors.affiliation: Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: I
authors.initials: I
authors.lastname: Carmichael
authors.affiliation: Institut für Ionenphysik und Angewandte Physik and Center for Molecular Biosciences Innsbruck (CMBI), Leopold Franzens Universität Innsbruck, Technikerstrasse 25, A-6020, Austria. Linda.Feketeova@uibk.ac.at Stephan.Denifl@uibk.ac.at and Université de Lyon, 69003 Lyon, France and CNRS/IN2P3, UMR5822, Institut de Physique Nucléaire de Lyon, 69622 Villeurbanne, France.
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-7472-0639
authors.initials: L
authors.lastname: Feketeová
authors.affiliation: Institut für Ionenphysik und Angewandte Physik and Center for Molecular Biosciences Innsbruck (CMBI), Leopold Franzens Universität Innsbruck, Technikerstrasse 25, A-6020, Austria. Linda.Feketeova@uibk.ac.at Stephan.Denifl@uibk.ac.at.
authors.forename: S
authors.initials: S
authors.lastname: Denifl
mesh_terms: D004583:Electrons; D006859:Hydrogen / Q000737:chemistry*; D006865:Hydrogenation; D007093:Imidazoles / Q000737:chemistry*; D008956:Models, Chemical
chemical_list: D007093:Imidazoles; C029899:imidazole; D006859:Hydrogen