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Temperature and anion ligand field dependence of LnCl3 (Ln = Nd, Dy, Sm) electronic absorption spectra in LiCl–KCl eutectic molten salt. PROGRESS IN NUCLEAR ENERGY 2023. [DOI: 10.1016/j.pnucene.2023.104584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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2
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Emerson MS, Sharma S, Roy S, Bryantsev VS, Ivanov AS, Gakhar R, Woods ME, Gallington LC, Dai S, Maltsev DS, Margulis CJ. Complete Description of the LaCl 3–NaCl Melt Structure and the Concept of a Spacer Salt That Causes Structural Heterogeneity. J Am Chem Soc 2022; 144:21751-21762. [DOI: 10.1021/jacs.2c09987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Matthew S. Emerson
- Department of Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Shobha Sharma
- Department of Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Santanu Roy
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Vyacheslav S. Bryantsev
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Alexander S. Ivanov
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Ruchi Gakhar
- Pyrochemistry and Molten Salt Systems Department, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States
| | - Michael E. Woods
- Pyrochemistry and Molten Salt Systems Department, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States
| | - Leighanne C. Gallington
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Lemont, Illinois 60439, United States
| | - Sheng Dai
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Dmitry S. Maltsev
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Claudio J. Margulis
- Department of Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
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Dhumal NR, Seol K, Isaev D, Helminen M, Williams B, Latortue S. Effect of Bulky Anion around the Dication on the Electronic Structure and Normal Frequencies in 1,3-Bis(3-methylimidazolium-1-yl)propane Bis(trifluoromethanesulfonyl)imide Ionic Liquid. ACS OMEGA 2021; 6:23293-23299. [PMID: 34549129 PMCID: PMC8444328 DOI: 10.1021/acsomega.1c03017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
A manifestation of hydrogen bonding between the dication and anions attributed to their relative position of the anions around the cation can influence both the conformational equilibrium and the physical properties of ionic liquids. With this view, we studied the electronic structure and normal frequencies using density functional theory calculations to analyze the hydrogen-bonding interactions in dicationic ionic liquids. The conformers are distinguished based on the hydrogen-bonding sites of the cation and anion. The weak hydrogen bonding between the dication and anions in dication ionic liquids can lead to greater conformational equilibrium compared to the monocation system. Consequences of these interactions for the vibrational spectrum are analyzed to provide an insight into the conformational equilibrium in dicationic ionic liquids at the molecular level.
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Affiliation(s)
- Nilesh R. Dhumal
- Department of Chemistry and
Physics, Florida Gulf Coast University, Fort Myers, Florida 33965, United States
| | - Kyung Seol
- Department of Chemistry and
Physics, Florida Gulf Coast University, Fort Myers, Florida 33965, United States
| | - Dmitry Isaev
- Department of Chemistry and
Physics, Florida Gulf Coast University, Fort Myers, Florida 33965, United States
| | - Michelle Helminen
- Department of Chemistry and
Physics, Florida Gulf Coast University, Fort Myers, Florida 33965, United States
| | - Brooke Williams
- Department of Chemistry and
Physics, Florida Gulf Coast University, Fort Myers, Florida 33965, United States
| | - Sherly Latortue
- Department of Chemistry and
Physics, Florida Gulf Coast University, Fort Myers, Florida 33965, United States
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Jiang S, Lan J, Wang L, Liu Y, Zhong Y, Liu Y, Yuan LLY, Zheng L, Chai Z, Shi W. Competitive Coordination of Chloride and Fluoride Anions Towards Trivalent Lanthanide Cations (La 3+ and Nd 3+ ) in Molten Salts. Chemistry 2021; 27:11721-11729. [PMID: 34105835 DOI: 10.1002/chem.202101505] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Indexed: 11/08/2022]
Abstract
Molten salt electrolysis is a vital technique to produce high-purity lanthanide metals and alloys. However, the coordination environments of lanthanides in molten salts, which heavily affect the related redox potential and electrochemical properties, have not been well elucidated. Here, the competitive coordination of chloride and fluoride anions towards lanthanide cations (La3+ and Nd3+ ) is explored in molten LiCl-KCl-LiF-LnCl3 salts using electrochemical, spectroscopic, and computational approaches. Electrochemical analyses show that significant negative shifts in the reduction potential of Ln3+ occur when F- concentration increases, indicating that the F- anions interact with Ln3+ via substituting the coordinated Cl- anions, and confirm [LnClx Fy ]3-x-y (ymax =3) complexes are prevailing in molten salts. Spectroscopic and computational results on solution structures further reveal the competition between Cl- and F- anions, which leads to the formation of four distinct Ln(III) species: [LnCl6 ]3- , [LnCl5 F]3- , [LnCl4 F2 ]3- and [LnCl4 F3 ]4- . Among them, the seven-coordinated [LnCl4 F3 ]4- complex possesses a low-symmetry structure evidenced by the pattern change of Raman spectra. After comparing the polarizing power (Z/r) among different metal cations, it was concluded that Ln-F interaction is weaker than that between transition metal and F- ions.
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Affiliation(s)
- Shilin Jiang
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianhui Lan
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Lin Wang
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Yalan Liu
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuke Zhong
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yichuan Liu
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Liyong L-Y Yuan
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Lirong Zheng
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhifang Chai
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.,Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Weiqun Shi
- Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
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6
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Roy S, Brehm M, Sharma S, Wu F, Maltsev DS, Halstenberg P, Gallington LC, Mahurin SM, Dai S, Ivanov AS, Margulis CJ, Bryantsev VS. Unraveling Local Structure of Molten Salts via X-ray Scattering, Raman Spectroscopy, and Ab Initio Molecular Dynamics. J Phys Chem B 2021; 125:5971-5982. [PMID: 34037400 DOI: 10.1021/acs.jpcb.1c03786] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, we resolve a long-standing issue concerning the local structure of molten MgCl2 by employing a multimodal approach, including X-ray scattering and Raman spectroscopy, along with the theoretical modeling of the experimental spectra based on ab initio molecular dynamics (AIMD) simulations utilizing several density functional theory (DFT) methods. We demonstrate the reliability of AIMD simulations in achieving excellent agreement between the experimental and simulated spectra for MgCl2 and 50 mol % MgCl2 + 50 mol % KCl, and ZnCl2, thus allowing structural insights not directly available from experiment alone. A thorough computational analysis using five DFT methods provides a convergent view that octahedrally coordinated magnesium in pure MgCl2 upon melting preferentially coordinates with five chloride anions to form distorted square pyramidal polyhedra that are connected via corners and to a lesser degree via edges. This is contrasted with the results for ZnCl2, which does not change its tetrahedral coordination on melting. Although the five-coordinate MgCl53- complex was not considered in the early literature, together with an increasing tendency to form a tetrahedrally coordinated complex with decreasing the MgCl2 content in the mixture with alkali metal chloride systems, current work reconciles the results of most previous seemingly contradictory experimental studies.
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Affiliation(s)
- Santanu Roy
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Martin Brehm
- Institut für Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany
| | - Shobha Sharma
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Fei Wu
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Dmitry S Maltsev
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Phillip Halstenberg
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.,Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Leighanne C Gallington
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Shannon M Mahurin
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Sheng Dai
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.,Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Alexander S Ivanov
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Claudio J Margulis
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Vyacheslav S Bryantsev
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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7
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Zakiryanov D, Tkachev N. Local structure and vibrational properties of molten lead halides PbX2 (X = Cl, Br, I) from ab initio molecular dynamics. COMPUT THEOR CHEM 2019. [DOI: 10.1016/j.comptc.2019.03.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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8
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Deconvolution of conformational equilibria in methimazolium-based ionic liquid ion pair: Infrared spectroscopic and computational study. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.06.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Ishii Y, Kasai S, Salanne M, Ohtori N. Transport coefficients and the Stokes–Einstein relation in molten alkali halides with polarisable ion model. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1046527] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Yoshiki Ishii
- Graduate School of Science and Technology, Niigata University , Niigata, Japan
| | - Satoshi Kasai
- Graduate School of Science and Technology, Niigata University , Niigata, Japan
| | - Mathieu Salanne
- Sorbonne Universités , UPMC Univ Paris 06, CNRS, UMR 8234, PHENIX, Paris, France
- Maison de la Simulation, CEA – CNRS – INRIA – Université Paris-Sud – Université de Versailles , Gif-sur-Yvette, France
| | - Norikazu Ohtori
- Department of Chemistry, Niigata University , Niigata, Japan
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10
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Cikit S, Akdeniz Z, Madden PA. Structure and Raman Spectra in Cryolitic Melts: Simulations with an ab Initio Interaction Potential. J Phys Chem B 2014; 118:1064-70. [PMID: 24432905 DOI: 10.1021/jp4080459] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Serpil Cikit
- Department
of Mathematics, Halic University, Istanbul, Turkey
| | - Zehra Akdeniz
- Faculty
of Science and Letters, Piri Reis University, 34940 Tuzla, Istanbul, Turkey
| | - Paul A. Madden
- Department
of Materials, University of Oxford, Parks Road, OX1 3PH, United Kingdom
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11
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12
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Estager J, Holbrey JD, Swadźba-Kwaśny M. Halometallate ionic liquids – revisited. Chem Soc Rev 2014; 43:847-86. [DOI: 10.1039/c3cs60310e] [Citation(s) in RCA: 212] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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14
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15
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Pauvert O, Salanne M, Zanghi D, Simon C, Reguer S, Thiaudière D, Okamoto Y, Matsuura H, Bessada C. Ion Specific Effects on the Structure of Molten AF-ZrF4 Systems (A+ = Li+, Na+, and K+). J Phys Chem B 2011; 115:9160-7. [DOI: 10.1021/jp203137h] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Olivier Pauvert
- CNRS-CEMHTI, 1D avenue de la Recherche Scientifique, UPR 3079, F-45071, Orléans, France
- Université d’Orléans, Avenue du Parc Floral, BP 6749, F-45067, Orléans, France
- European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125, Karlsruhe, Germany
| | - Mathieu Salanne
- UPMC Univ Paris 06, CNRS, ESPCI, UMR 7195, PECSA, F-75005 Paris, France
| | - Didier Zanghi
- CNRS-CEMHTI, 1D avenue de la Recherche Scientifique, UPR 3079, F-45071, Orléans, France
- Université d’Orléans, Avenue du Parc Floral, BP 6749, F-45067, Orléans, France
| | - Christian Simon
- UPMC Univ Paris 06, CNRS, ESPCI, UMR 7195, PECSA, F-75005 Paris, France
| | - Solenn Reguer
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP 48, F-91192, Gif-sur-Yvette, France
| | - Dominique Thiaudière
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP 48, F-91192, Gif-sur-Yvette, France
| | - Yoshihiro Okamoto
- Department of Materials Science, Japan Atomic Energy Research Institute, Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
| | - Haruaki Matsuura
- Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 Meguro-ku, Tokyo 152-8550, Japan
| | - Catherine Bessada
- CNRS-CEMHTI, 1D avenue de la Recherche Scientifique, UPR 3079, F-45071, Orléans, France
- Université d’Orléans, Avenue du Parc Floral, BP 6749, F-45067, Orléans, France
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16
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Rollet AL, Salanne M. Studies of the local structures of molten metal halides. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1pc90003j] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Hudry D, Rakhmatullin A, Bessada C, Bardez I, Bart F, Jobic S, Deniard P. Reactivity of NH4H2PO4 toward LaCl3 in LiCl-KCl Melt Flux. Step by Step Formation of Monazite-Like LaPO4. Inorg Chem 2009; 48:7141-50. [DOI: 10.1021/ic9003142] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Damien Hudry
- Institut des Matériaux Jean Rouxel, Université de Nantes-CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France
- CEA Marcoule DTCD/SECM/LDMC, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Aydar Rakhmatullin
- Conditions Extrêmes et Matériaux: Haute Température et Irradiation (CEMHTI), CNRS, 45071 Orléans cedex 2, France
- Université d’Orléans, Faculté des Sciences, BP 6749, 45067 Orléans cedex 2, France
| | - Catherine Bessada
- Conditions Extrêmes et Matériaux: Haute Température et Irradiation (CEMHTI), CNRS, 45071 Orléans cedex 2, France
- Université d’Orléans, Faculté des Sciences, BP 6749, 45067 Orléans cedex 2, France
| | - Isabelle Bardez
- CEA Marcoule DTCD/SECM/LDMC, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Florence Bart
- CEA Marcoule DTCD/SECM/LDMC, BP 17171, 30207 Bagnols-sur-Cèze cedex, France
| | - Stéphane Jobic
- Institut des Matériaux Jean Rouxel, Université de Nantes-CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France
| | - Philippe Deniard
- Institut des Matériaux Jean Rouxel, Université de Nantes-CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes cedex 3, France
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Buz’ko VY, Kushkhov KB, Buz’ko MB, Panyushkin VT. Ab initio study of the structure and stability of LaCl n (3 − n)+ complexes (n = 1−8). RUSS J INORG CHEM+ 2008. [DOI: 10.1134/s0036023608110181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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The Chemical Environment of Ionic Liquids: Links Between Liquid Structure, Dynamics, and Solvation. ADVANCES IN CHEMICAL PHYSICS 2008. [DOI: 10.1002/9780470259498.ch2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
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21
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Rollet AL, Godier S, Bessada C. High temperature NMR study of the local structure of molten LaF3–AF (A = Li, Na, K and Rb) mixtures. Phys Chem Chem Phys 2008; 10:3222-8. [DOI: 10.1039/b719158h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Dhumal NR. Molecular interactions in 1,3-dimethylimidazolium-bis(trifluromethanesulfonyl)imide ionic liquid. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.10.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Miani A, Raugei S, Carloni P, Helfand MS. Structure and Raman Spectrum of Clavulanic Acid in Aqueous Solution. J Phys Chem B 2007; 111:2621-30. [PMID: 17302447 DOI: 10.1021/jp066135u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The calculation of the vibrational Raman spectrum of enzyme-bound beta-lactamase inhibitors may be of help to understand the mechanisms responsible for bacterial drug resistance. Here, we present a study of the solvation structure and the vibrational properties of clavulanate, an important beta-lactamase inhibitor, in aqueous solution as obtained from full quantum and hybrid empirical/quantum molecular dynamics simulations at ambient conditions. The analysis of the vibrational density of states indicates that hybrid empirical/quantum mechanical simulations are able to properly describe the vibrational levels of clavulanate in solution. In addition, we propose a computationally efficient protocol to calculate the vibrational Raman effect for large solute molecules in water, which is able to faithfully reproduce the experimentally recorded clavulanate Raman spectrum and discloses the possibility to employ hybrid simulations to assign the experimental Raman spectra of inhibitors bound to beta-lactamases.
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Affiliation(s)
- Andrea Miani
- SISSA/ISAS and INFM-DEMOCRITOS, Modeling Center for Research in Atomistic Simulation, via Beirut 2, I-34014, Trieste, Italy
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24
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Kobrak MN. Characterization of the solvation dynamics of an ionic liquid via molecular dynamics simulation. J Chem Phys 2006; 125:64502. [PMID: 16942293 DOI: 10.1063/1.2227026] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The solvation dynamics of ionic liquids have been the subject of intense experimental study but remain poorly understood. We present the results of molecular dynamics simulations of the solvation dynamics of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate in response to photoexcitation of the fluorescent dye coumarin-153. We reproduce the time-resolved fluorescence Stokes shift using linear response theory, then use novel statistical techniques to analyze cation and anion contributions to the signal. We find that the solvation dynamics are dominated by collective ionic motion and characterize the time scale for various features of the collective response. Further, we use the Steele analysis [Mol. Phys. 61, 1031 (1987)] to characterize the contributions to the observed Stokes shift made by translational and rovibrational degrees of freedom. Our results indicate that in contrast to molecular liquids, the rovibrational response is trivial and the observed fluorescence response arises almost entirely from ionic translation. Our results resolve previously open questions in the literature about the nature of the rapid dynamics in room-temperature ionic liquids and offer insight into the physical principles governing ionic liquid behavior on longer time scales.
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Affiliation(s)
- Mark N Kobrak
- Department of Chemistry, Brooklyn College of the City University of New York, 2900 Bedford Ave., Brooklyn, New York 11210, USA.
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25
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Akdeniz Z, Madden PA. Raman Spectra of Ionic Liquids: A Simulation Study of AlF3 and Its Mixtures with NaF. J Phys Chem B 2006; 110:6683-91. [PMID: 16570973 DOI: 10.1021/jp060064h] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Theoretical Raman spectra of the melts of NaF/AlF3 mixtures have been obtained from computer simulations in order to examine how the Raman spectra reflect the coordination structure around the Al3+ ions. The Raman spectra, both polarized and depolarized, are calculated from a model for the dependence of the polarizability of the system on the ionic coordinates which was inspired by electronic structure calculations of the polarizabilities of ions in a condensed-phase environment. The shapes of the spectra and their evolution with composition in the mixtures conform remarkably well to those seen experimentally, and we discuss the relationship between the bands seen in the spectra and the vibrational modes of the AlFn(3-n) coordination complexes which are found in the melts. Finally, we calculate quantities which relate to the degree of cross-linking between these coordination complexes and their lifetimes.
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Affiliation(s)
- Zehra Akdeniz
- Department of Physics, Istanbul University, Istanbul, Turkey
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26
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Wang Y, Li H, Han S. Structure and conformation properties of 1-alkyl-3-methylimidazolium halide ionic liquids: A density-functional theory study. J Chem Phys 2005; 123:174501. [PMID: 16375540 DOI: 10.1063/1.1979478] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The structures and conformational properties of 1-alkyl-3-methylimidazolium halide ionic liquids have been studied with a Becke's 3 Parameter functional method. The interaction mechanisms between the cation and the anion in 1-ethyl-3-methylimidazolium (Emim+) halide and 1-butyl-3-methylimidazolium (Bmim+) halide ionic liquids were investigated using 6-31G*, 6-31++G**, and 6-311++G** basis sets. Forty structures of different ion pairs were optimized and geometrical parameters of them have been discussed in details. Halide ions (Cl- or Br-) have been gradually placed in different regions around imidazolium cation and the interaction energies between the anion and the cation have been calculated. Theoretical results indicate that there are four activity regions in the vicinity of the imidazolium cations, in these regions the imidazolium cations and the halide anions formed stable ion pairs. Imidazolium cations can form hydrogen bond interactions with one, two or three but no more than three nearest halide anions. The halide ions are situated in hydrogen bond positions rather than at random.
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Affiliation(s)
- Yong Wang
- Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China
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27
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Hazebroucq S, Picard GS, Adamo C, Heine T, Gemming S, Seifert G. Density-functional-based molecular-dynamics simulations of molten salts. J Chem Phys 2005; 123:134510. [PMID: 16223317 DOI: 10.1063/1.2038888] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The physicochemical properties of two molten salts, namely, KCl and NaCl, have been studied with a molecular-dynamics approach using a density-functional-based tight-binding (DFTB) model. The obtained results have been compared with a number of previously reported simulations, carried out on smaller systems and using classical force-field techniques. A good agreement has been found for both structural parameters and macroscopic properties, such as self-diffusion coefficients. Furthermore, our DFTB results are very close to the available experimental data. From a more general point of view, our results demonstrate the applicability of DFTB as an efficient tool in the modeling of melts. At the same time, the quality of the obtained results supports the use of this as a reliable alternative to the more expensive ab initio dynamics approaches, if accurate parameters are provided.
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Affiliation(s)
- Sandrine Hazebroucq
- Laboratoire d'Electrochimie et de Chimie Analytique, Centre National de la Recherche Scientifique (CNRS) UMR-7575, Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05, France
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Hazebroucq S, Picard GS, Adamo C. A theoretical investigation of gadolinium (III) solvation in molten salts. J Chem Phys 2005; 122:224512. [PMID: 15974696 DOI: 10.1063/1.1931648] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The solvation of lanthanides [here Gd(III)] in molten LiCl and KCl has been studied using a classical solvation approach, based on clusters of increasing size. In particular, density-functional calculations have been carried out on charged and neutral clusters, containing up to 35 chlorine halide molecules. A number of properties have been then evaluated and analyzed, including structural, vibrational, and thermochemical data. Special attention has also been devoted to the analysis of the local structure of the solvent surrounding the Gd3+ cation, a problem deeply investigated by experimentalists. Our results show that the charged clusters are not suitable to model the first solvation shell in such species, since their structures are strongly affected by the large electrostatic contribution. In contrast, more reliable simulations are obtained using the neutral clusters. In the latter, the coordination of Gd(III) in molten salts is computed to be 8 or 6, according to the salt LiCl or KCl. Furthermore, a good agreement is found with the experimental structural data and Raman spectra. Finally, preliminary results of potential interest for the estimation of solvation thermodynamics, a key parameter for exploiting molten salt chemistry, are reported for neutral clusters.
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Affiliation(s)
- Sandrine Hazebroucq
- Laboratoire d'Electrochimie et de Chimie Analytique, Centre National de la Recherche Scientifique Unite Mixte de Recherche 7575, Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05, France
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Brookes R, Davies A, Ketwaroo G, Madden PA. Diffusion Coefficients in Ionic Liquids: Relationship to the Viscosity. J Phys Chem B 2004; 109:6485-90. [PMID: 16851727 DOI: 10.1021/jp046355c] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The relationship between the diffusion coefficient and the viscosity has been examined in computer simulations for a number of ions diffusing in a molten salt (alkali halide) solvent. The comparison gives a measure of a hydrodynamic radius for the diffusing ions which is then compared with the bare ionic radius and a characteristic radius of the coordination complex formed by halide ions around polyvalent cations. K(+) and Cl(-) ions appear to diffuse as isolated spherical particles, whereas the trivalent cations Sc(3+), Y(3+), and La(3+) diffuse as if with an intact coordination shell. These different behaviors can be related to the time scale for the relaxation of the coordination shell, compared to the structural relaxation time of the solvent.
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Affiliation(s)
- Richard Brookes
- Chemistry Department, University of Oxford, South Parks Road, OX1 3QZ, UK
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Glover WJ, Madden PA. Raman spectra of ionic liquids: A simulation study of LaCl3 and its mixtures with alkali chlorides. J Chem Phys 2004; 121:7293-303. [PMID: 15473798 DOI: 10.1063/1.1792574] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Theoretical Raman spectra of the elpasolite-structured crystal Cs2NaLaCl6 and of molten mixtures of LaCl6 with NaCl and CsCl have been obtained from computer simulations in order to examine how the Raman spectra reflect the coordination structure around the La3+ ions. This system is a model for many other trivalent metal halides and for examining how the network structure of the pure melts is broken down by the addition of alkali halides with different structure-breaking powers. The results suggest a way of reconciling the conclusions of Raman studies about the structures of the melts with those of neutron and x-ray-diffraction studies, which have already been examined with the same simulation methods. The Raman spectra, both polarized and depolarized, are calculated from a model for the dependence of the polarizability of the system on the ionic coordinates which was inspired by electronic structure calculations of the polarizabilities of ions in a condensed phase environment. Some results on the lifetimes of the coordination complexes responsible for the appearance of the discrete Raman bands are discussed.
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Affiliation(s)
- William J Glover
- Chemistry Department, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
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Zissi GD, Papatheodorou GN. Composition and temperature induced changes on the structure of molten ScCl3–CsCl mixtures. Phys Chem Chem Phys 2004. [DOI: 10.1039/b408289c] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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