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Auburger P, Kemeny I, Bertram C, Ligges M, Bockstedte M, Bovensiepen U, Morgenstern K. Microscopic Insight into Electron-Induced Dissociation of Aromatic Molecules on Ice. PHYSICAL REVIEW LETTERS 2018; 121:206001. [PMID: 30500234 DOI: 10.1103/physrevlett.121.206001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Indexed: 06/09/2023]
Abstract
We use scanning tunneling microscopy, photoelectron spectroscopy, and ab initio calculations to investigate the electron-induced dissociation of halogenated benzene molecules adsorbed on ice. Dissociation of halobenzene is triggered by delocalized excess electrons attaching to the π^{*} orbitals of the halobenzenes from where they are transferred to σ^{*} orbitals. The latter orbitals provide a dissociative potential surface. Adsorption on ice sufficiently lowers the energy barrier for the transfer between the orbitals to facilitate dissociation of bromo- and chloro- but not of flourobenzene at cryogenic temperatures. Our results shed light on the influence of environmentally important ice particles on the reactivity of halogenated aromatic molecules.
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Affiliation(s)
- Philipp Auburger
- Solid State Theory, Friedrich-Alexander University Erlangen-Nürnberg, Staudstr. 7B2, D-91058 Erlangen, Germany
| | - Ishita Kemeny
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
| | - Cord Bertram
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
- Physical Chemistry I, Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| | - Manuel Ligges
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
| | - Michel Bockstedte
- Solid State Theory, Friedrich-Alexander University Erlangen-Nürnberg, Staudstr. 7B2, D-91058 Erlangen, Germany
- Department of Chemistry and Physics of Materials, Paris-Lodron University Salzburg, Jakob-Haringer-Str. 2a, A-5020 Salzburg, Austria
| | - Uwe Bovensiepen
- Faculty of Physics, University of Duisburg-Essen, Lotharstr. 1, D-47057 Duisburg, Germany
| | - Karina Morgenstern
- Physical Chemistry I, Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
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Plane JMC, Feng W, Dawkins ECM. The mesosphere and metals: chemistry and changes. Chem Rev 2015; 115:4497-541. [PMID: 25751779 PMCID: PMC4448204 DOI: 10.1021/cr500501m] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Indexed: 12/03/2022]
Affiliation(s)
- John M. C. Plane
- School of Chemistry, National Centre
for Atmospheric Science, and School of Earth
and Environment, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Wuhu Feng
- School of Chemistry, National Centre
for Atmospheric Science, and School of Earth
and Environment, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Erin C. M. Dawkins
- School of Chemistry, National Centre
for Atmospheric Science, and School of Earth
and Environment, University of Leeds, Leeds LS2 9JT, United Kingdom
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Meyer M, Agarwal I, Wolf M, Bovensiepen U. Ultrafast electron dynamics at water covered alkali adatoms adsorbed on Cu(111). Phys Chem Chem Phys 2015; 17:8441-8. [PMID: 25639630 DOI: 10.1039/c4cp05356g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Here we report on the ultrafast electron dynamics of the alkalis Na, K, and Cs coadsorbed with D2O on Cu(111) surfaces, which we investigated with femtosecond time-resolved two-photon photoemission. The well known transient electronic binding energy stabilization in bare adsorbed alkalis is enhanced by the presence of water which acts as a solvent and increases the transient energy gain. We observe for all adsorbed alkalis a transient binding energy stabilization of 100-300 meV. The stabilization rates range from 1 to 2 eV ps(-1). Here the heavier alkali exhibits a slower stabilization which we explain by their weaker static alkali-water interaction observed in thermal desorption spectroscopy. The population dynamics at low water coverage is described by a single exponential. With increasing water coverage the behavior becomes non-exponential suggesting an additional excited state due to electron solvation.
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Affiliation(s)
- Michael Meyer
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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Vondrak T, Meech SR, Plane JMC. Photoelectric emission from the alkali metal doped vacuum-ice interface. J Chem Phys 2009; 130:054702. [PMID: 19206984 DOI: 10.1063/1.3063658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The photoelectron photoemission spectra and thresholds for low coverages of Li and K adsorbed on water-ice have been measured, compared with photoionization spectra of the gas-phase atoms, and modeled by quantum chemical calculations. For both alkali metals the threshold for photoemission is dramatically decreased and the cross section increased on adsorption to the water-ice surface. Quantum chemical calculations suggest that the initial state is formed by the metal atoms adsorbed into the water-ice surface, forming a state with a delocalized electron distribution. This state is metastable and decays on the hundreds of seconds time scale at 92 K. The decay is markedly faster for Li than for K, probably due to diffusion into the ice film.
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Affiliation(s)
- Tomas Vondrak
- School of Chemistry, University of Leeds, Leeds LS2 9JT, United Kingdom
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