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Kuusik I, Berholts M, Kruusma J, Tõnisoo A, Lust E, Nõmmiste E, Kisand V. Valence electronic structure of [EMIM][B(CN)4]: ion-pair vs. bulk description. RSC Adv 2019; 9:33140-33146. [PMID: 35529163 PMCID: PMC9073151 DOI: 10.1039/c9ra06762k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 10/10/2019] [Indexed: 11/21/2022] Open
Abstract
The ultraviolet photoelectron spectrum of the [EMIM][B(CN)4] ionic liquid was recorded and analyzed. Together with different ab initio calculation methods, detailed insight into the electronic structure of this simple room temperature ionic liquid is possible. The ion-pair approximation to the liquid electronic structure was not sufficient. Therefore bulk ab initio calculations were performed on a proposed crystal structure. The modelling of bulk electronic spectra is able to explain the experimental electronic structure of the ionic liquid. Most notably, the dispersion corrected PBE calculation (PBE-D3BJ) showed good agreement with the experimental UPS spectrum. The spectra simulated by the B97-D and the BLYP-D3(BJ) functionals were also in agreement with the experimental data. The LDA approximation only provided qualitative agreement while the optB88-vdW and CX-vdW functionals were not good. However, it will be shown that many requirements have to be met in order to accurately describe the electronic structure of this ionic liquid. The ultraviolet photoelectron spectrum of the [EMIM][B(CN)4] ionic liquid was recorded and simulated using different ab initio ion-pair and bulk calculation methods.![]()
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Affiliation(s)
- I. Kuusik
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - M. Berholts
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
- Dept. of Physics and Astronomy
| | - J. Kruusma
- Institute of Chemistry
- University of Tartu
- 50411 Tartu
- Estonia
| | - A. Tõnisoo
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - E. Lust
- Institute of Chemistry
- University of Tartu
- 50411 Tartu
- Estonia
| | - E. Nõmmiste
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - V. Kisand
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
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Kukk E, Thomas TD, Céolin D, Granroth S, Travnikova O, Berholts M, Marchenko T, Guillemin R, Journel L, Ismail I, Püttner R, Piancastelli MN, Ueda K, Simon M. Energy Transfer into Molecular Vibrations and Rotations by Recoil in Inner-Shell Photoemission. Phys Rev Lett 2018; 121:073002. [PMID: 30169107 DOI: 10.1103/physrevlett.121.073002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Indexed: 06/08/2023]
Abstract
A mixture of CF_{4} and CO gases is used to study photoelectron recoil effects extending into the tender x-ray region. In CF_{4}, the vibrational envelope of the C 1s photoelectron spectrum becomes fully dominated by the recoil-induced excitations, revealing vibrational modes hidden from Franck-Condon excitations. In CO, using CF_{4} as an accurate energy calibrant, we determine the partitioning of the recoil-induced internal excitation energy between rotational and vibrational excitation. The observed rotational recoil energy is 2.88(28) times larger than the observed vibrational recoil energy, well in excess of the ratio of 2 predicted by the basic recoil model. The experiment is, however, in good agreement with the value of 2.68 if energy transfer via Coriolis coupling is included.
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Affiliation(s)
- E Kukk
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
| | - T D Thomas
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - D Céolin
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, B.P. 48, FR-91192 Gif-sur-Yvette Cedex, France
| | - S Granroth
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
| | - O Travnikova
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
| | - M Berholts
- Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
- Department of Physics, University of Tartu, EST-50411 Tartu, Estonia
| | - T Marchenko
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
| | - R Guillemin
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
| | - L Journel
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
| | - I Ismail
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
| | - R Püttner
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin-Dahlem, Germany
| | - M N Piancastelli
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
- Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala, Sweden
| | - K Ueda
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - M Simon
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, B.P. 48, FR-91192 Gif-sur-Yvette Cedex, France
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
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Kuusik I, Berholts M, Kruusma J, Kisand V, Tõnisoo A, Lust E, Nõmmiste E. Valence electronic structure of [EMIM][BF4] ionic liquid: photoemission and DFT+D study. RSC Adv 2018; 8:30298-30304. [PMID: 35546846 PMCID: PMC9085424 DOI: 10.1039/c8ra05865b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/22/2018] [Indexed: 11/21/2022] Open
Abstract
The ultraviolet photoelectron spectrum (UPS) of the [EMIM][BF4] ionic liquid was recorded and analyzed. Together with the gas-phase UPS spectrum of the [EMIM][BF4] vapor and ab initio calculation methods, detailed insight into the electronic structure of this simple ionic liquid is possible. The low binding energy tail in the UPS spectrum is about 7.4 eV, in agreement with previous estimations of the HOMO–LUMO gap of the [EMIM][BF4] ion-pair. The bulk ab initio calculations are able to explain most of the features in the spectrum. However, DFT consistently lacks accuracy in the description of the top of the valence band. The dispersion corrected PBE calculation (PBE-D3) did offer very good agreement with the experimental structure, but the recently-developed vdW-DF functionals C09, optPBE, optB88 and CX were found to offer the best agreement in terms of the electronic structure. The ultraviolet photoelectron spectrum (UPS) of the [EMIM][BF4] ionic liquid was recorded and compared to previously measured vapor phase UPS spectrum.![]()
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Affiliation(s)
- I. Kuusik
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - M. Berholts
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
- Dept. of Physics and Astronomy
| | - J. Kruusma
- Institute of Chemistry
- University of Tartu
- 50411 Tartu
- Estonia
| | - V. Kisand
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - A. Tõnisoo
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
| | - E. Lust
- Institute of Chemistry
- University of Tartu
- 50411 Tartu
- Estonia
| | - E. Nõmmiste
- Institute of Physics
- University of Tartu
- 50411 Tartu
- Estonia
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