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Michoulier E, Ben Amor N, Rapacioli M, Noble JA, Mascetti J, Toubin C, Simon A. Theoretical determination of adsorption and ionisation energies of polycyclic aromatic hydrocarbons on water ice. Phys Chem Chem Phys 2018; 20:11941-11953. [PMID: 29667677 DOI: 10.1039/c8cp01175c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In dense interstellar environments, Polycyclic Aromatic Hydrocarbons (PAHs) are likely to condense onto or integrate into water ice mantles covering dust grains. Understanding the role of ice in the photo-induced processes involving adsorbed PAHs is therefore a key issue in astrochemistry. This requires (i) the knowledge of PAH-ice interactions, i.e. PAH-ice adsorption energies and local structures at the PAH-ice interface, as well as (ii) the understanding of the fate of electrons in the PAH-ice system upon excitation. Regarding (i), in this work, we determined the lowest energy structures of PAH-ice systems for a variety of PAHs ranging from naphthalene to ovalene on three types of ice - crystalline (Ih and Ic) and amorphous (low density) - using an explicit description of the electrons and a finite-sized system. The electronic structure was determined using the Self Consistent Charge Density Functional based Tight Binding (SCC-DFTB) scheme with modified Mulliken charges in order to ensure a good description of the studied systems. Regarding (ii), the influence of the interaction with ice on the Vertical Ionisation Potentials (VIPs) of the series of PAHs was determined using the constrained SCC-DFTB scheme benchmarked against correlated wavefunction results for PAH-(H2O)n (n = 1-6, 13) clusters. The results show a deviation equal, at most, to ∼1.4 eV of the VIPs of PAHs adsorbed on ice with respect to the gas phase values. Our results are discussed in the light of experimental data and previous theoretical studies.
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Affiliation(s)
- Eric Michoulier
- Lab. Chim. & Phys. Quant. LCPQ IRSAMC, Univ. Toulouse [UPS] UPS & CNRS, UMR5626, 118 Route Narbonne, F-31062, Toulouse, France.
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2
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Dawes A, Pascual N, Hoffmann SV, Jones NC, Mason NJ. Vacuum ultraviolet photoabsorption spectroscopy of crystalline and amorphous benzene. Phys Chem Chem Phys 2018; 19:27544-27555. [PMID: 28979950 DOI: 10.1039/c7cp05319c] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We present the first high resolution vacuum ultraviolet photoabsorption study of amorphous benzene with comparisons to annealed crystalline benzene and the gas phase. Vapour deposited benzene layers were grown at 25 K and annealed to 90 K under conditions pertinent to interstellar icy dust grains and icy planetary bodies in our solar system. Three singlet-singlet electronic transitions in solid benzene correspond to the 1B2u, 1B1u and 1E1u states, redshifted by 0.05, 0.25 and 0.51 eV respectively with respect to the gas phase. The symmetry forbidden 1B2u ← 1A1g and 1B1u ← 1A1g transitions exhibit vibronic structure due to vibronic coupling and intensity borrowing from the allowed 1E1u ← 1A1g transition. Additionally the 1B2u ← 1A1g structure shows evidence of coupling between intramolecular vibrational and intermolecular lattice modes in crystalline benzene with Davydov crystal field splitting observed. The optically forbidden 0-0 electronic origin is clearly visible as a doublet at 4.69/4.70 eV in the crystalline solid and as a weak broadened feature at 4.67 eV in amorphous benzene. In the case of the 1B1u ← 1A1g transition the forbidden 0-0 electronic origin is only observed in crystalline benzene as an exciton peak at 5.77 eV. Thicker amorphous benzene samples show diffuse bands around 4.3, 5.0 and 5.4 eV that we tentatively assign to spin forbidden singlet-triplet 3B2u ← 1A1g, 3E1u ← 1A1g and 3B1u ← 1A1g transitions respectively, not previously reported in photoabsorption spectra of amorphous benzene. Furthermore, our results show clear evidence of non-wetting or 'islanding' of amorphous benzene, characterised by thickness-dependent Rayleigh scattering tails at wavelengths greater than 220 nm. These results have significant implications for our understanding of the physical and chemical properties and processes in astrochemical ices and highlight the importance of VUV spectroscopy.
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Affiliation(s)
- Anita Dawes
- School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, Mk7 6AA, UK.
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Kania R, Malongwe JK, Nachtigallová D, Krausko J, Gladich I, Roeselová M, Heger D, Klán P. Spectroscopic Properties of Benzene at the Air–Ice Interface: A Combined Experimental–Computational Approach. J Phys Chem A 2014; 118:7535-47. [DOI: 10.1021/jp501094n] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rafał Kania
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | | | - Dana Nachtigallová
- Institute
of Organic Chemistry and Biochemistry, AS CR, v.v.i., Flemingovo nam. 2, 166 10 Prague, Czech Republic
| | - Ján Krausko
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Department
of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Ivan Gladich
- International
School for Advanced Studies (SISSA), Via Bonomea 265, I-34136, Trieste, Italy
| | - Martina Roeselová
- Institute
of Organic Chemistry and Biochemistry, AS CR, v.v.i., Flemingovo nam. 2, 166 10 Prague, Czech Republic
| | - Dominik Heger
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Department
of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Petr Klán
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
- Department
of Chemistry, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
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Petitjean M, Hantal G, Chauvin C, Mirabel P, Le Calvé S, Hoang PNM, Picaud S, Jedlovszky P. Adsorption of benzaldehyde at the surface of ice, studied by experimental method and computer simulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:9596-9606. [PMID: 20329716 DOI: 10.1021/la100169h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Adsorption study of benzaldehyde on ice surfaces is performed by combining experimental and theoretical approaches. The experiments are conducted over the temperature range 233-253 K using a coated wall flow tube coupled to a mass spectrometric detector. Besides the experimental way, the adsorption isotherm is also determined by performing a set of grand canonical Monte Carlo simulations at 233 K. The experimental and calculated adsorption isotherms show a very good agreement within the corresponding errors. Besides, both experimental and theoretical studies permit us to derive the enthalpy of adsorption of benzaldehyde on ice surfaces DeltaH(ads), which are in excellent agreement: DeltaH(ads) = -61.4 +/- 9.7 kJ/mol (experimental) and DeltaH(ads) = -59.4 +/- 5.1 kJ/mol (simulation). The obtained results indicate a much stronger ability of benzaldehyde of being adsorbed at the surface of ice than that of small aliphatic aldehydes, such as formaldehyde or acetaldehyde. At low surface coverages the adsorbed molecules exclusively lie parallel with the ice surface. With increasing surface coverage, however, the increasing competition of the adsorbed molecules for the surface area to be occupied leads to the appearance of two different perpendicular orientations relative to the surface. In the first orientation, the benzaldehyde molecule turns its aldehyde group toward the ice phase, and, similarly to the molecules in the lying orientation, forms a hydrogen bond with a surface water molecule. In the other perpendicular orientation the aldehyde group turns to the vapor phase, and its O atom interacts with the delocalized pi system of the benzene ring of a nearby lying benzaldehyde molecule of the second molecular layer. In accordance with this observed scenario, the saturated adsorption layer, being stable in a roughly 1 kJ/mol broad range of chemical potentials, contains, besides the first molecular layer, also traces of the second molecular layer of adsorbed benzaldehyde.
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Affiliation(s)
- Mélanie Petitjean
- Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse (LMSPC, UMR 7515 CNRS/UdS), 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
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Vácha R, Cwiklik L, Řezáč J, Hobza P, Jungwirth P, Valsaraj K, Bahr S, Kempter V. Adsorption of Aromatic Hydrocarbons and Ozone at Environmental Aqueous Surfaces. J Phys Chem A 2008; 112:4942-50. [DOI: 10.1021/jp711813p] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Robert Vácha
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Lukasz Cwiklik
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Jan Řezáč
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Pavel Hobza
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Kalliat Valsaraj
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Stephan Bahr
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
| | - Volker Kempter
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic, Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803-7303, Institut für Physik and Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany, and Institut für Physik, Universität Osnabrück, Barbarastr. 7, D
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