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Romero M, Kushnir JS, Mochi B, Velez C, Acevedo O. Monte Carlo QM/MM simulation studies of the Cannizzaro reaction in ionic liquids for improved biofuel production. J Chem Phys 2024; 161:084117. [PMID: 39206828 DOI: 10.1063/5.0222092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Accepted: 08/12/2024] [Indexed: 09/04/2024] Open
Abstract
The conversion of biomass to 5-hydroxymethylfurfural (HMF) holds substantial promise as a renewable energy source. Notably, HMF can be transformed into 2,5-bis(hydroxymethyl)furan (BHMF), a crucial reactant in biofuel production, but requires harsh operating conditions, H2, and precious metal catalysts. A recently reported Cannizzaro reaction of HMF to BHMF, characterized by its efficiency, mild conditions, and eco-friendliness, instead employed ionic liquids (ILs) to achieve high yields. In this study, combined quantum mechanical and molecular mechanical (QM/MM) simulations in conjunction with Metropolis Monte Carlo statistical mechanics and free-energy perturbation theory utilized M06-2X/6-31+G(d), PDDG/PM3, and the OPLS-VSIL force field to uncover important solute-solvent interactions present in the HMF to BHMF reaction pathway. The Cannizzaro reaction was examined in water and in five ILs composed of the 1-butyl-3-methylimidazolium [BMIM] cation coupled to hexafluorophosphate, tetrafluoroborate, thiocyanate, chloride, and bromide. Energetic and structural analysis of the rate-determining hydride transfer between HMF and the hydride-donor anion HMFOH- attributed the enhanced reactivity to highly organized solvent interactions featuring (1) hydrogen bonding between the ring protons of [BMIM] and the negatively charged carbonyl oxygen atoms on the transition structure, (2) favorable electrostatic interactions between the IL anions and solute hydroxyl groups, and (3) beneficial π-π stacking interactions between [BMIM] and the two aromatic rings present in HMF and HMFOH-.
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Affiliation(s)
- Maria Romero
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA
| | - Jamie S Kushnir
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA
| | - Bruno Mochi
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA
| | - Caroline Velez
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA
| | - Orlando Acevedo
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, USA
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2
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Piccoli V, Martínez L. Competitive Effects of Anions on Protein Solvation by Aqueous Ionic Liquids. J Phys Chem B 2024; 128:7792-7802. [PMID: 39092664 PMCID: PMC11331513 DOI: 10.1021/acs.jpcb.4c03735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/12/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024]
Abstract
The present study utilizes molecular dynamics simulations to examine how different anions compete for protein solvation in aqueous solutions of ionic liquids (ILs). Ubiquitin is used as model protein and studied in IL mixtures sharing the same cation, 1-ethyl-3-methylimidazolium (EMIM), and two different anions in the same solution, from combinations of dicyanamide (DCA), chloride (Cl), nitrate (NO3), and tetrafluoroborate (BF4). Our findings reveal that specific interactions between anions and the protein are paramount in IL solvation, but that combinations of anions are not additive. For example, DCA exhibits a remarkable ability to form hydrogen bonds with the protein, resulting in a significantly stronger preferential binding to the protein than other anions. However, the combination of DCA with NO3, which also forms hydrogen bonds with the protein, results in a smaller preferential solvation of the protein than the combination of DCA with chloride ions, which are weaker binders. Thus, combining anions with varying affinities for the protein surface modulates the overall ion accumulation through nonadditive mechanisms, highlighting the importance of the understanding of competition for specific interaction sites, cooperative binding, bulk-solution affinity, and overall charge compensations, on the overall solvation capacity of the solution. Such knowledge may allow for the design of novel IL-based processes in biotechnology and material science, where fine-tuning protein solvation is crucial for optimizing performance and functionality.
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Affiliation(s)
- Vinicius Piccoli
- Institute of Chemistry and
Center for Computing in Engineering & Science, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-872, SP, Brazil
| | - Leandro Martínez
- Institute of Chemistry and
Center for Computing in Engineering & Science, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-872, SP, Brazil
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3
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Memar ZO, Moosavi M. Assessing OPLS-based force fields for investigating the characteristics of imidazolium-based dicationic ionic liquids: A comparative study with AIMD simulations and experimental findings. J Chem Phys 2023; 159:244504. [PMID: 38149743 DOI: 10.1063/5.0180900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/04/2023] [Indexed: 12/28/2023] Open
Abstract
In this study, we extended the optimized potentials for liquid simulation-ionic-liquid virtual site (OPLS-VSIL) force field (FF) to imidazolium-based dicationic ionic liquids (DILs) and evaluated the ability of different OPLS-based FFs (i.e., OPLS-2009IL, 0.8*OPLS-2009IL, and OPLS-VSIL) in predicting different properties of the studied DIL by comparing their results with ab initio molecular dynamics (AIMD) simulation and experimental results. To achieve this purpose, MD simulations with three different OPLS-based FFs as well as AIMD simulation were performed for [C3(mim)2][NTF2]2 DIL and its structural, dynamical, vibrational, and volumetric properties were analyzed. Structural properties of the studied DIL, i.e., radial distribution functions (RDFs), structure factor, and hydrogen-bond network, showed that compared to 0.8*OPLS-2009IL FF, there is a much better agreement between the results of both OPLS-2009IL and OPLS-VSIL FFs with the AIMD simulation. On the other hand, the results of dynamical properties, such as mean square displacements, van Hove correlation functions as well as hydrogen bond, ion pair, and ion cage dynamics, depicted that in both 0.8*OPLS-2009IL and OPLS-VSIL FFs, the dynamics of the system is almost similar, and compared to OPLS-2009IL FF, they have better agreements with experimental results where they exist. So, it can be seen that although reducing the total charge of studied DIL by 20% leads to an increase in the dynamics of the system, the type distribution of partial charges on each atom does not significantly affect the system's dynamics. The calculated infrared (IR) and power spectra showed that the vibrational features of studied DIL in three OPLS-based FFs are mostly the same and reducing total charge and different type distribution of partial charges have no significant effect on the studied system. Furthermore, in volumetric properties, OPLS-VSIL FF shows somehow better agreement with experimental results. Overall, the evaluation of different structural, dynamical, vibrational, and volumetric properties of [C3(mim)2][NTF2]2 DIL shows that the OPLS-VSIL FF may be the best choice among the different studied OPLS FFs.
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Affiliation(s)
| | - Majid Moosavi
- Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Iran
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4
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Wang S, Li Z, Yang G, Lin J, Xu Q. Molecular dynamics study of fluorosulfonyl ionic liquids as electrolyte for electrical double layer capacitors. RSC Adv 2023; 13:29886-29893. [PMID: 37842684 PMCID: PMC10571016 DOI: 10.1039/d3ra04798a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 09/29/2023] [Indexed: 10/17/2023] Open
Abstract
The development of high-performance supercapacitors is an important goal in the field of energy storage. Ionic liquids (ILs) are promising electrolyte materials for efficient energy storage in supercapacitors, because of the high stability, low volatility, and wider electrochemical stability window than traditional electrolytes. However, ILs-based supercapacitors usually show a relatively lower power density owing to the inherent viscosity-induced low electrical conductivity. Fluorosulfonyl ILs have aroused much attention in energy storage devices due to its low toxicity and excellent stability. Here, we propose that structural modification is an effective way to improve the energy storage performance of fluorosulfonyl ILs through the classical molecular dynamics (MD) method. Four fluorosulfonyl ILs with different sizes and symmetries were considered. Series of properties including conductivity, interface structure, and double-layer capacitance curves were systematically investigated. The results show that smaller size and more asymmetric structure can enhance self-diffusion coefficient and conductivity, and improve the electrochemical performance. Appropriate modification of the electrodes can further enhance the capacitive performance. Our work provides an opportunity to further understand and develop the fluorosulfonyl ILs electrolyte in supercapacitors.
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Affiliation(s)
- Siqi Wang
- College of Physics, Changchun Normal University Changchun 130032 China
| | - Zhuo Li
- College of Physics, Changchun Normal University Changchun 130032 China
| | - Guangmin Yang
- College of Physics, Changchun Normal University Changchun 130032 China
| | - Jianyan Lin
- College of Physics, Changchun Normal University Changchun 130032 China
| | - Qiang Xu
- College of Prospecting and Surveying Engineering, Changchun Institute of Technology Changchun 130021 China
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Yue K, Acevedo O. Uncovering the Critical Factors that Enable Extractive Desulfurization of Fuels in Ionic Liquids and Deep Eutectic Solvents from Simulations. J Phys Chem B 2023. [PMID: 37413969 DOI: 10.1021/acs.jpcb.3c02652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Environmental regulatory agencies have implemented stringent restrictions on the permissible levels of sulfur compounds in fuel to reduce harmful emissions and improve air quality. Problematically, traditional desulfurization methods have shown low effectiveness in the removal of refractory sulfur compounds, e.g., thiophene (TS), dibenzothiophene (DBT), and 4-methyldibenzothiophene (MDBT). In this work, molecular dynamics (MD) simulations and free energy perturbation (FEP) have been applied to investigate the use of ionic liquids (ILs) and deep eutectic solvents (DESs) as efficient TS/DBT/MDBT extractants. For the IL simulations, the selected cation was 1-butyl-3-methylimidazolium [BMIM] and the anions included chloride [Cl], thiocyanate [SCN], tetrafluoroborate [BF4], hexafluorophosphate [PF6], and bis(trifluoromethylsulfonyl)amide [NTf2]. The DESs were composed of choline chloride with ethylene glycol (CCEtg) or with glycerol (CCGly). Calculation of excess chemical potentials predicted the ILs to be more promising extractants with energies lower by 1-3 kcal/mol compared to DESs. Increasing IL anion size was positively correlated to enhanced solvation of S-compounds, which was influenced by energetically dominant solute-anion interactions and favorable solute-[BMIM] π-π stacking. For the DESs, the solvent components offered a range of synergistic, yet comparatively weaker, electrostatic interactions that included hydrogen bonding and cation-π interactions. An in-depth analysis of the structure of IL and DES systems is presented, along with a discussion of the critical factors behind experimental trends of S-compound extraction efficiency.
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Affiliation(s)
- Kun Yue
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Orlando Acevedo
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
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Roos E, Sebastiani D, Brehm M. A force field for bio-polymers in ionic liquids (BILFF) - part 2: cellulose in [EMIm][OAc]/water mixtures. Phys Chem Chem Phys 2023; 25:8755-8766. [PMID: 36897117 DOI: 10.1039/d2cp05636d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
We present the extension of our force field BILFF (Bio-Polymers in Ionic Liquids Force Field) to the bio-polymer cellulose. We already published BILFF parameters for mixtures of ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) with water. Our all-atom force field focuses on a quantitative reproduction of the hydrogen bonds in the complex mixture of cellulose, [EMIm]+, [OAc]- and water when compared to reference ab initio molecular dynamics (AIMD) simulations. To enhance the sampling, 50 individual AIMD simulations starting from different initial configurations were performed for cellulose in solvent instead of one long simulation, and the resulting averages were used for force field optimization. All cellulose force field parameters were iteratively adjusted starting from the literature force field of W. Damm et al. We were able to obtain a very good agreement with respect to both the microstructure of the reference AIMD simulations and experimental results such as the system density (even at higher temperatures) and the crystal structure. Our new force field allows performing very long simulations of large systems containing cellulose solvated in (aqueous) [EMIm][OAc] with almost ab initio accuracy.
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Affiliation(s)
- Eliane Roos
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Daniel Sebastiani
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Martin Brehm
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
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7
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Sookhaki E, Zolghadr AR, Namazian M. The effect of various partial atomic charges on the bulk and liquid/vacuum interface properties of iodobenzene derivatives at their melting points. J Mol Graph Model 2023; 119:108400. [PMID: 36586348 DOI: 10.1016/j.jmgm.2022.108400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/04/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022]
Abstract
In this work, various atomic charge schemes including natural bond orbital (NBO), electrostatic potential based (CHELPG), and σ-hole model charges were applied in the OPLS-AA force field to investigate their effects on the thermophysical and structural properties of iodobenzene and its derivatives. Molecular dynamics simulations presented in this work show that the studied structural and thermophysical properties are in good agreement with experiments when the CHELPG charge was coupled with the OPLS-AA force field. Also, the arrangement of iodobenzene derivatives in the liquid phase was investigated via combined radial/angular distribution functions (CDFs) analyses and halogen-bonding theory. The most probable orientation of iodobenzene derivatives at the liquid/vacuum interface was assigned by atom density profile and bivariate orientational distribution maps. For all studied iodobenzene derivatives, benzene rings are oriented such that the iodine atoms tend toward the vacuum phase.
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Affiliation(s)
- Elham Sookhaki
- Department of Chemistry, Yazd University, Yazd, Iran; Department of Chemistry, Shiraz University, Shiraz, 71946-84795, Iran
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8
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Relaxation, temporal diffusion, and polarity of aromatic hydrocarbons in ionic liquid. APPLIED NANOSCIENCE 2022. [DOI: 10.1007/s13204-022-02696-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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9
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Piccoli V, Martínez L. Ionic liquid solvation of proteins in native and denatured states. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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10
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Oh YH, Kim DW, Lee S. Ionic Liquids as Organocatalysts for Nucleophilic Fluorination: Concepts and Perspectives. Molecules 2022; 27:5702. [PMID: 36080470 PMCID: PMC9457570 DOI: 10.3390/molecules27175702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
Besides their extremely useful properties as solvent, ionic liquids (ILs) are now considered to be highly instructive tools for enhancing the rates of chemical reactions. The ionic nature of the IL anion and cation seems to be the origin of this fascinating function of ILs as organocatalyst/promoter through their strong Coulombic forces on other ionic species in the reaction and also through the formation of hydrogen bonds with various functional groups in substrates. It is now possible to tailor-make ILs for specific purposes as solvent/promoters in a variety of situations by carefully monitoring these interactions. Despite the enormous potentiality, it seems that the application of ILs as organocatalysts/promoters for chemical reactions have not been fully achieved so far. Herein, we review recent developments of ILs for promoting the nucleophilic reactions, focusing on fluorination. Various aspects of the processes, such as organocatalytic capability, reaction mechanisms and salt effects, are discussed.
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Affiliation(s)
- Young-Ho Oh
- Department of Applied Chemistry, Kyung Hee University, Duckyoung-daero 1732, Yongin City 446-701, Korea
| | - Dong Wook Kim
- Department of Chemistry, Inha University, 100 Inha-ro, Nam-gu, Incheon 402-751, Korea
| | - Sungyul Lee
- Department of Applied Chemistry, Kyung Hee University, Duckyoung-daero 1732, Yongin City 446-701, Korea
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11
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Yue K, Doherty B, Acevedo O. Comparison between Ab Initio Molecular Dynamics and OPLS-Based Force Fields for Ionic Liquid Solvent Organization. J Phys Chem B 2022; 126:3908-3919. [PMID: 35594504 DOI: 10.1021/acs.jpcb.2c01636] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OPLS-based force fields (FFs) have been shown to provide accurate bulk-phase properties for a wide variety of imidazolium-based ionic liquids (ILs). However, the ability of OPLS to reproduce an IL solvent structure is not as well-validated given the relative lack of high-level theoretical or experimental data available for comparison. In this study, ab initio molecular dynamics (AIMD) simulations were performed for three widely used ILs: the 1-butyl-3-methylimidazolium cation with chloride, tetrafluoroborate, or hexafluorophosphate anions, that is, [BMIM][Cl], [BMIM][BF4], and [BMIM][PF6], respectively, as a basis for further assessment of two unique IL FFs: the ±0.8 charge-scaled OPLS-2009IL FF and the OPLS-VSIL FF. The OPLS-2009IL FF employs a traditional all-atom functional form, whereas the OPLS-VSIL FF was developed using a virtual site that offloads negative charge to inside the plane of the ring with careful attention given to reproducing hydrogen bonding. Detailed comparisons between AIMD and the OPLS FFs were made based on radial distribution functions (RDFs), combined distribution functions (CDFs), and spatial distribution functions (SDFs) to examine cation-anion interactions and π+-π+ stacking between the imidazolium rings. While both FFs were able to correctly capture the general solvent structure of these popular ILs, the OPLS-VSIL FF quantitatively reproduced interaction distances more accurately. In addition, this work provides further insights into the different short- and long-range structure patterns of these popular ILs.
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Affiliation(s)
- Kun Yue
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Brian Doherty
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Orlando Acevedo
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
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12
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Zhang L, Wang SL, Tan Y, Tao GH, Yuan WL, Fu J, Zhang GH, He L, Tao G. Hydrogen-bonding and "π-π" interaction promoted solution-processable mixed matrix membranes for aromatic amines detection. JOURNAL OF HAZARDOUS MATERIALS 2022; 430:128490. [PMID: 35739671 DOI: 10.1016/j.jhazmat.2022.128490] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/30/2022] [Accepted: 02/12/2022] [Indexed: 06/15/2023]
Abstract
Detection of hazardous compounds can alleviate risk to human health. However, it remains a challenge to develop easy-to-use testing tools for carcinogenic aromatic amines. Herein, we presented a conjugated molecule-based aniline detector, mixed matrix membranes (MMMs), through the solution-processable strategy. The pentacene-based dispersed phase is achieved using the state-of-the-art ionic liquids (ILs) as the continuous phase, based on which MMMs are easily manufactured by a solution process. Moreover, molecular dynamics (MD) simulations and quantum mechanical calculations suggested that hydrogen bonding and π-π interaction between ILs cations and pentacene could promote the dissolution. These prepared MMMs can offer easy-operation and on-site detection of carcinogenic primary aromatic amines with eye-readable fluorescence signal. This work provides a paradigm for the design of a portable testing device for various hazardous compounds.
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Affiliation(s)
- Lei Zhang
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Shuang-Long Wang
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Yunshu Tan
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Guo-Hong Tao
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Wen-Li Yuan
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Jie Fu
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Guo-Hao Zhang
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China
| | - Ling He
- College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, China.
| | - Guohua Tao
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
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Li L, Lin J, Fu F, Dai Z, Zhou G, Yang Z. Molecular-Level Understanding of Surface Roughness Boosting Segregation Behavior at the ZIF-8/Ionic Liquid Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:4175-4187. [PMID: 35349284 DOI: 10.1021/acs.langmuir.1c02922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Here, we perform a series of classical molecular dynamics simulations for two different [HEMIM][DCA] and [BMIM][BF4] ionic liquids (ILs) on the ZIF-8 surface to explore the interfacial properties of metal-organic framework (MOFs)/IL composite materials at the molecular level. Our simulation results reveal that the interfacial structures of anions and cations on the ZIF-8 surface are dominated by the surface roughness due to the steric hindrance, which is extremely different from the driving mechanism based on solid-ion interactions of ILs on flat solid surfaces. At the ZIF-8/IL interfaces, the open sodalite (SOD) cages of the ZIF-8 surface can block most of the large-size cations outside and significantly boost the segregation behavior of anions and cations. In comparison with the [BMIM][BF4] IL, the [HEMIM][DCA] IL has much more anions entering into the open SOD cages owing to the combination of stronger ZIF-8-[DCA]- interactions and more ordered arrangement of [DCA]- anions on the ZIF-8 surface. Furthermore, more and stronger ZIF-8-[BF4]- hydrogen bonds (HBs) are found to exist on the cage edges than the ZIF-8-[DCA]- HBs, further preventing [BF4]- anions from entering into SOD cages. By more detailed analyses, we find that the hydrophobic interaction has an important influence on the interfacial structures of the side chains of [HEMIM]+ and [BMIM]+ cations, while the π-π stacking interaction plays a key role in determining the interfacial structures of the imidazolium rings of both cations. Our simulation results in this work provide a molecular-level understanding of the underlying driving mechanism on segregation behavior at the ZIF-8/IL interfaces.
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Affiliation(s)
- Li Li
- Institute of Advanced Materials (IAM), State-Province Joint Engineering Laboratory of Zeolite Membrane Materials, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China
| | - Jie Lin
- Institute of Advanced Materials (IAM), State-Province Joint Engineering Laboratory of Zeolite Membrane Materials, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China
| | - Fangjia Fu
- School of Mathematical Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Zhongyang Dai
- National Supercomputing Center in Shenzhen, Shenzhen 518055, People's Republic of China
| | - Guobing Zhou
- Institute of Advanced Materials (IAM), State-Province Joint Engineering Laboratory of Zeolite Membrane Materials, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China
| | - Zhen Yang
- Institute of Advanced Materials (IAM), State-Province Joint Engineering Laboratory of Zeolite Membrane Materials, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China
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14
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Qu M, Li S, Chen J, Xiao Y, Xiao J. Ion Transport in the EMITFSI/PVDF System at Different Temperatures: A Molecular Dynamics Simulation. ACS OMEGA 2022; 7:9333-9342. [PMID: 35356691 PMCID: PMC8945056 DOI: 10.1021/acsomega.1c06160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/02/2022] [Indexed: 05/13/2023]
Abstract
We used all-atom molecular dynamics simulations to study the ion transport in the 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide/poly(vinylidene fluoride) (EMITFSI/PVDF) system with 40.05 wt % EMITFSI at different temperatures. The glass-transition temperature (T g = 204 K) of this system shows a good agreement with the experimental value (200 K). With the increase of temperature, the peaks of the pair correlation function show an increasing trend. Interestingly, the coordination numbers of ion pairs and the degree of independent ion motion are mainly affected by the binding energy between ion pairs as the temperature increases. In addition, the ion transport properties with increasing temperature can be studied by the ion-pair relaxation times, ion-pair lifetimes, and diffusion coefficients. The simulation results illustrate that the ion transport is intensified. Especially, the cations can always diffuse faster than the anions. The power law shows that mobilities of anions and cations are seen to exhibit a "superionic" behavior. With the increase of temperature, transference numbers of anions decrease first and then increase and transference numbers of cations show the opposite changes; ionic conductivity increases gradually; and viscosity decreases gradually, indicating that the diffusion resistance of ions decreases. In general, after adding PVDF into the EMITFSI system, the glass-transition temperature and viscosity increase, the ionic conductivity and degree of independent ion motion decrease, and diffusion coefficients of cations decrease faster than those of the anions.
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Affiliation(s)
- Minghe Qu
- Molecules
and Materials Computation Institute, School of Chemistry and Chemical
Engineering, Nanjing University of Science
and Technology, Nanjing 210094, P. R. China
| | - Shenshen Li
- Molecules
and Materials Computation Institute, School of Chemistry and Chemical
Engineering, Nanjing University of Science
and Technology, Nanjing 210094, P. R. China
| | - Jian Chen
- Chuannan
Machinery Manufacturing Plant, Luzhou 646000, P. R. China
| | - Yunqin Xiao
- Molecules
and Materials Computation Institute, School of Chemistry and Chemical
Engineering, Nanjing University of Science
and Technology, Nanjing 210094, P. R. China
- Science
and Technology on Aerospace Chemical Power Laboratory, Hubei Institute of Aerospace Chemical Technology, Xiangyang 441003, P. R. China
| | - Jijun Xiao
- Molecules
and Materials Computation Institute, School of Chemistry and Chemical
Engineering, Nanjing University of Science
and Technology, Nanjing 210094, P. R. China
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15
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MOLECULAR SIMULATIONS OF DEEP EUTECTIC SOLVENTS: A PERSPECTIVE ON STRUCTURE, DYNAMICS, AND PHYSICAL PROPERTIES. REVIEWS IN COMPUTATIONAL CHEMISTRY 2022. [DOI: 10.1002/9781119625933.ch4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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16
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Kirchner B, Blasius J, Alizadeh V, Gansäuer A, Hollóczki O. Chemistry Dissolved in Ionic Liquids. A Theoretical Perspective. J Phys Chem B 2022; 126:766-777. [PMID: 35034453 DOI: 10.1021/acs.jpcb.1c09092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The theoretical treatment of ionic liquids must focus now on more realistic models while at the same time keeping an accurate methodology when following recent ionic liquids research trends or allowing predictability to come to the foreground. In this Perspective, we summarize in three cases of advanced ionic liquid research what methodological progress has been made and point out difficulties that need to be overcome. As particular examples to discuss we choose reactions, chirality, and radicals in ionic liquids. All these topics have in common that an explicit or accurate treatment of the electronic structure and/or intermolecular interactions is required (accurate methodology), while at the same time system size and complexity as well as simulation time (realistic model) play an important role and must be covered as well.
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Affiliation(s)
- Barbara Kirchner
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstraße 4+6, D-53115 Bonn, Germany
| | - Jan Blasius
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstraße 4+6, D-53115 Bonn, Germany
| | - Vahideh Alizadeh
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstraße 4+6, D-53115 Bonn, Germany
| | - Andreas Gansäuer
- Kekulé-Institut für Organische Chemie und Biochemie, University of Bonn, Gerhard-Domagk-Straße 1, D-53121 Bonn, Germany
| | - Oldamur Hollóczki
- Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstraße 4+6, D-53115 Bonn, Germany.,Department of Physical Chemistry, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, H-4010 Debrecen, Hungary
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17
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Velez C, Acevedo O. Simulation of deep eutectic solvents: Progress to promises. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1598] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Caroline Velez
- Department of Chemistry University of Miami Coral Gables Florida USA
| | - Orlando Acevedo
- Department of Chemistry University of Miami Coral Gables Florida USA
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18
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Madarász Á, Hamza A, Ferenc D, Bakó I. Two Faces of the Two-Phase Thermodynamic Model. J Chem Theory Comput 2021; 17:7187-7194. [PMID: 34648287 PMCID: PMC8582254 DOI: 10.1021/acs.jctc.1c00156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The quantum harmonic
model and the two-phase thermodynamic method
(2PT) are widely used to obtain quantum-corrected properties such
as isobaric heat capacities or molar entropies. 2PT heat capacities
were calculated inconsistently in the literature. For water, the classical
heat capacity was also considered, but for organic liquids, it was
omitted. We reanalyzed the performance of different quantum corrections
on the heat capacities of common organic solvents against experimental
data. We have pointed out serious flaws in previous 2PT studies. The
vibrational density of states was calculated incorrectly causing a
39% relative error in diffusion coefficients and 45% error in the
2PT heat capacities. The wrong conversion of isobaric and isochoric
heat capacities also caused about 40% error but in the other direction.
We have introduced the concept of anharmonic correction (AC), which
is simply the deviation of the classical heat capacity from that of
the harmonic oscillator model. This anharmonic contribution is around
+30 to 40 J/(mol K) for water depending on the water model and −8
to −10 J/(mol K) for hydrocarbons and halocarbons. AC is unrealistically
large, +40 J/(K mol) for alcohols and amines, indicating some deficiency
of the OPLS force field. The accuracy of the computations was also
assessed with the determination of the self-diffusion coefficients.
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Affiliation(s)
- Ádám Madarász
- Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| | - Andrea Hamza
- Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
| | - Dávid Ferenc
- Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary.,Institute of Chemistry, ELTE, Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary
| | - Imre Bakó
- Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
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19
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Molecular dynamic insight into solubility of H2S in ionic liquids [emim][BF4], [emim][OTf] and [emim][Tf2N]. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Avula NVS, Karmakar A, Kumar R, Balasubramanian S. Efficient Parametrization of Force Field for the Quantitative Prediction of the Physical Properties of Ionic Liquid Electrolytes. J Chem Theory Comput 2021; 17:4274-4290. [PMID: 34097391 DOI: 10.1021/acs.jctc.1c00268] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The prediction of transport properties of room-temperature ionic liquids from nonpolarizable force field-based simulations has long been a challenge. The uniform charge scaling method has been widely used to improve the agreement with the experiment by incorporating the polarizability and charge transfer effects in an effective manner. While this method improves the performance of the force fields, this prescription is ad hoc in character; further, a quantitative prediction is still not guaranteed. In such cases, the nonbonded interaction parameters too need to be refined, which requires significant effort. In this work, we propose a three-step semiautomated refinement procedure based on (1) atomic site charges obtained from quantum calculations of the bulk condensed phase; (2) quenched Monte Carlo optimizer to shortlist suitable force field candidates, which are then tested using pilot simulations; and (3) manual refinement to further improve the accuracy of the force field. The strategy is designed in a sequential manner with each step improving the accuracy over the previous step, allowing the users to invest the effort commensurate with the desired accuracy of the refined force field. The refinement procedure is applied on N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide (DEME-TFSI), a front-runner as an electrolyte for electric double-layer capacitors and single-molecule-based devices. The transferability of the refined force field is tested on N,N-dimethyl-N-ethyl-N-methoxyethoxyethylammonium bis(trifluoromethanesulfonyl)imide (N112,2O2O1-TFSI). The refined force field is found to be better at predicting both structural and transport properties compared to the uniform charge scaling procedure, which showed a discrepancy in the X-ray structure factor. The refined force field showed quantitative agreement with structural (density and X-ray structure factor) and transport properties-diffusion coefficients, ionic conductivity, and shear viscosity over a wide temperature range, building a case for the wide adoption of the procedure.
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Affiliation(s)
- Nikhil V S Avula
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Anwesa Karmakar
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Rahul Kumar
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Sundaram Balasubramanian
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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21
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Bodo E. Modelling biocompatible ionic liquids based on organic acids and amino acids: challenges for computational models and future perspectives. Org Biomol Chem 2021; 19:4002-4013. [PMID: 33978045 DOI: 10.1039/d1ob00011j] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this short review I shall highlight the basic principle and the difficulties that arise in attempting the computational modeling of seemingly simple systems which hide an unexpected complexity. Biocompatible ionic liquids which are based on the coupling of organic or amino acid anions with metabolic cations such as cholinium are the target of this review. These substances have been the subject of intense research activities in the last few years and have attracted the attention of computational chemists. I shall show that the computational description of these substances is far from trivial and requires the use of sophisticated techniques in order to account for a surprisingly rich chemistry that is due to several phenomena such as polarization, charge transfer, proton transfer equilibria and tautomerization reactions.
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Affiliation(s)
- Enrico Bodo
- Chemistry Department, University of Rome "La Sapienza", P. A. Moro 5, 00185 Rome, Italy.
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22
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Zhong X, Velez C, Acevedo O. Partial Charges Optimized by Genetic Algorithms for Deep Eutectic Solvent Simulations. J Chem Theory Comput 2021; 17:3078-3087. [PMID: 33885293 DOI: 10.1021/acs.jctc.1c00047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Deep eutectic solvents (DESs) are a class of solvents often composed of ammonium-based chloride salts and a neutral hydrogen bond donor (HBD) at specific ratios. These cost-effective and environmentally friendly solvents have seen significant growth in multiple fields, including organic synthesis, and in materials and extractions because of their desirable properties. In the present work, a new software called genetic algorithm machine learning (GAML) was developed that utilizes a genetic algorithm (GA) approach to facilitate the development of optimized potentials for liquid simulation (OPLS)-based force field (FF) parameters for eight unique DESs based on three ammonium-based salts and five HBDs at multiple salt:HBD ratios. As an initial test of GAML, partial charges were created for 86 conventional solvents based on neutral organic molecules that yielded excellent overall mean absolute deviations (MADs) of 0.021 g/cm3, 0.63 kcal/mol, and 0.20 kcal/mol compared to experimental densities, heats of vaporization (ΔHvap), and free energies of hydration (ΔGhyd), respectively. FFs for DESs constructed from ethylammonium, N,N-diethylethanolammonium, and N-ethyl-N,N-dimethylethanolammonium chloride salts were then parameterized using GAML with exceptional agreement achieved at multiple temperatures for experimental densities, surface tensions, and viscosities with MADs of 0.024 g/cm3, 4.2 mN/m, and 5.3 cP, respectively.
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Affiliation(s)
- Xiang Zhong
- Department of Chemistry, University of Miami Coral Gables, Florida 33146, United States
| | - Caroline Velez
- Department of Chemistry, University of Miami Coral Gables, Florida 33146, United States
| | - Orlando Acevedo
- Department of Chemistry, University of Miami Coral Gables, Florida 33146, United States
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23
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24
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Roos E, Brehm M. A force field for bio-polymers in ionic liquids (BILFF) - part 1: [EMIm][OAc]/water mixtures. Phys Chem Chem Phys 2021; 23:1242-1253. [PMID: 33355320 DOI: 10.1039/d0cp04537c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present BILFF, a novel force field for bio-polymers in ionic liquids. In the first part of our study, we introduce optimized force field parameters for mixtures of the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) with water. This imidazolium-based IL is of particular practical importance as it can dissolve significant amounts of cellulose even at room temperature. An understanding of this dissolution process via molecular dynamics simulations requires a quantitative description of the microscopic structure and the strong hydrogen bonds with a method able of simulating at least several dozen nanoseconds, which is the main aim of our novel force field. To reach this goal, we optimize the force field parameters to reproduce radial, spatial, and combined distribution functions, hydrogen bond lifetimes, diffusion coefficients, and several other quantities from reference ab initio molecular dynamics (AIMD) simulations. Non-trivial effects such as dispersion interactions between the side chains and π-π stacking of the cations are reproduced very well. We further validate the force field by comparison to experimental data such as thermal expansion coefficients, bulk modulus, and density at different temperatures, which yields good agreement and correct trends. No other force field with optimized parameters for mixtures of [EMIm][OAc] and water has been presented in the literature yet. Optimized force field parameters for cellulose and other ILs will be published in upcoming articles.
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Affiliation(s)
- Eliane Roos
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
| | - Martin Brehm
- Institut für Chemie - Theoretische Chemie, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
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25
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Velarde-Salcedo MV, Sánchez-Badillo J, Gallo M, López-Lemus J. Excess chemical potential of thiophene in [C 4MIM] [BF 4, Cl, Br, CH 3COO] ionic liquids, determined by molecular simulations. RSC Adv 2021; 11:29394-29406. [PMID: 35479577 PMCID: PMC9040597 DOI: 10.1039/d1ra04615b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/25/2021] [Indexed: 11/21/2022] Open
Abstract
The excess chemical potential of thiophene in imidazolium-based ionic liquids [C4mim][BF4], [C4mim][Cl], [C4mim][Br], and [C4mim][CH3COO] were determined by means of molecular dynamics in conjunction with free energy perturbation techniques employing non-polarizable force fields at 300 K and 343.15 K. In addition, energetic and structural analysis were performed such as: interaction energies, averaged noncovalent interactions, radial, and combined distribution functions. The results from this work revealed that the ionic liquids (ILs) presenting the most favorable excess chemical potentials ([C4mim][BF4], [C4mim][CH3COO]) are associated with the strongest energetic interaction between the thiophene molecule and the ionic liquid anion, and with the weakest energetic interaction between the thiophene molecule and the ionic liquid cation. Excess chemical potential of thiophene in imidazolium-based ionic liquids [C4mim][BF4], [C4mim][Cl], [C4mim][Br], and [C4mim][CH3COO] determined by molecular simulations.![]()
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Affiliation(s)
- Marco V. Velarde-Salcedo
- Facultad de Ciencias, Universidad Autónoma del Estado de México, Instituto Literario No. 100, Col. Centro, Toluca, Estado de México, C.P. 50000, Mexico
| | - Joel Sánchez-Badillo
- Facultad de Ingeniería en Tecnología de la Madera, Universidad Michoacana de San Nicolás de Hidalgo, Fco. J. Múgica S/N, Morelia, Michoacán, C. P. 58030, Mexico
| | - Marco Gallo
- Tecnológico Nacional de México/ITCJ, Av. Tecnológico 1340, Cd. Juárez, Chihuahua, C.P. 32500, Mexico
| | - Jorge López-Lemus
- Facultad de Ciencias, Universidad Autónoma del Estado de México, Instituto Literario No. 100, Col. Centro, Toluca, Estado de México, C.P. 50000, Mexico
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27
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Piccoli V, Martínez L. Correlated counterion effects on the solvation of proteins by ionic liquids. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114347] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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28
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Polok K, Beisert M, Swiątek A, Maity N, Piatkowski P, Gadomski W, Miannay FA, Idrissi A. Dynamics in the BMIM PF 6/acetonitrile mixtures observed by femtosecond optical Kerr effect and molecular dynamics simulations. Phys Chem Chem Phys 2020; 22:24544-24554. [PMID: 33094298 DOI: 10.1039/d0cp03847d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have performed the measurements of the optical Kerr effect signal time evolution up to 4 ns for a mixture of 1-alkyl-3-methyl-imidazolium hexafluorophosphate (BMIM PF6) ionic liquid and acetonitrile in the whole mole fractions range. The long delay line in our experimental setup allowed us to capture the complete reorientational dynamics of the ionic liquid. We have analysed the optical Kerr effect signal in the time and frequency domains with help of molecular dynamics simulations. In our approximation of the slow picosecond dynamics with a multi-exponential decay, we distinguish three relaxation times. The highest two are assigned to the reorientation of the cation and acetonitrile molecules that are in the vicinity of the imidazolium ring. The third one is recognized as originating from cation rotations and reorientation of acetonitrile molecules in the bulk or in the vicinity of the aliphatic chains of the cation. With help of the simulation we interpret the intermolecular band in the reduced spectral density, obtained from Kerr signal, as follows: its low-frequency side results from oscillations of one of the components in the cage formed by its neighbors, while the high-frequency side is attributed to the librations of the cation and acetonitrile molecule as well as the intermolecular oscillations of system components involved in specific interactions. We use this assignment and concentration dependence of the spectra obtained from velocity and angular velocity correlations to explain the mole fraction dependence of Kerr reduced spectral density.
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Affiliation(s)
- Kamil Polok
- Faculty of Chemistry, Laboratory of Spectroscopy and Intermolecular Interactions, University of Warsaw, Żwirki i Wigury 101, Warsaw 02-089, Poland.
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29
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Yalcin D, Welsh ID, Matthewman EL, Jun SP, Mckeever-Willis M, Gritcan I, Greaves TL, Weber CC. Structural investigations of molecular solutes within nanostructured ionic liquids. Phys Chem Chem Phys 2020; 22:11593-11608. [PMID: 32400798 DOI: 10.1039/d0cp00783h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Ionic liquids (ILs) containing sufficiently long alkyl chains form amphiphilic nanostructures with well-defined polar and non-polar domains. Here we have explored the robustness of these amphiphilic nanostructures to added solutes and gained insight into how the nature of the solute and IL ions affect the partitioning of these solutes within the nanostructured domains of ILs. To achieve this, small angle X-ray scattering (SAXS) investigations were performed and discussed for mixtures of 9 different molecular compounds with 6 different ILs containing imidazolium cations. The amphiphilic nanostructure of ILs persisted to high solute concentrations, over 50 mol% of added solute for most 1-butyl-3-methylimidazolium ILs and above 80 mol% for most 1-decyl-3-methylimidazolium ILs. Solute partitioning within these domains was found to be controlled by the inherent polarity and size of the solute, as well as specific interactions between the solute and IL ions, with SAXS results corroborated with IR spectroscopy and molecular dynamics simulations. Molecular dynamics simulations also revealed the ability to induce π+-π+ stacking between imidazolium cations through the use of these added molecular compounds. Collectively, these results provide scope for the selection of IL ions to rationally influence and control the partitioning behaviour of given solutes within the amphiphilic nanostructure of ILs.
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Affiliation(s)
- Dilek Yalcin
- School of Science, RMIT University, Melbourne, Australia
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Accurate Diels-Alder Energies and Endo Selectivity in Ionic Liquids Using the OPLS-VSIL Force Field. Int J Mol Sci 2020; 21:ijms21041190. [PMID: 32054023 PMCID: PMC7072795 DOI: 10.3390/ijms21041190] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/06/2020] [Accepted: 02/08/2020] [Indexed: 01/17/2023] Open
Abstract
Our recently developed optimized potentials for liquid simulations-virtual site ionic liquid (OPLS-VSIL) force field has been shown to provide accurate bulk phase properties and local ion-ion interactions for a wide variety of imidazolium-based ionic liquids. The force field features a virtual site that offloads negative charge to inside the plane of the ring with careful attention given to hydrogen bonding interactions. In this study, the Diels-Alder reaction between cyclopentadiene and methyl acrylate was computationally investigated in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], as a basis for the validation of the OPLS-VSIL to properly reproduce a reaction medium environment. Mixed ab initio quantum mechanics and molecular mechanics (QM/MM) calculations coupled to free energy perturbation and Monte Carlo sampling (FEP/MC) that utilized M06-2X/6-31G(d) and OPLS-VSIL gave activation free energy barriers of 14.9 and 16.0 kcal/mol for the endo-cis and exo-cis Diels-Alder reaction pathways, respectively (exptl. ΔH‡ of 14.6 kcal/mol). The endo selectivity trend was correctly predicted with a calculated 73% endo preference. The rate and selectivity enhancements present in the endo conformation were found to arise from preferential hydrogen bonding with the exposed C4 ring hydrogen on the BMIM cation. Weaker electronic stabilization of the exo transition state was predicted. For comparison, our earlier ±0.8 charge-scaled OPLS-2009IL force field also yielded a ΔG‡ of 14.9 kcal/mol for the favorable endo reaction pathway but did not adequately capture the highly organized solvent interactions present between the cation and Diels-Alder transition state.
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Sánchez-Badillo J, Gallo M, Guirado-López RA, López-Lemus J. Thermodynamic, structural and dynamic properties of ionic liquids [C 4mim][CF 3COO], [C 4mim][Br] in the condensed phase, using molecular simulations. RSC Adv 2019; 9:13677-13695. [PMID: 35519576 PMCID: PMC9063925 DOI: 10.1039/c9ra02058f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/23/2019] [Indexed: 11/21/2022] Open
Abstract
In this work a series of thermodynamic, structural, and dynamical properties for the 1-butyl-3-methylimidazolium trifluoroacetate ([C4mim][CF3COO]) and 1-butyl-3-methylimidazolium bromide, ([C4mim][Br]) ionic liquids (ILs) were calculated using Non-polarizable Force Fields (FF), parameterized using a methodology developed previously within the research group, for condensed phase applications. Properties such as the Vapor-Liquid Equilibrium (VLE) curve, critical points (ρ c, T c), Radial, Spatial and Combined Distribution Functions and self-diffusion coefficients were calculated using Equilibrium Molecular Dynamics simulations (EMD); other properties such as shear viscosities and thermal conductivities were calculated using Non-Equilibrium Molecular Dynamics simulations (NEMD). The results obtained in this work indicated that the calculated critical points are comparable with those available in the literature. The calculated structural information for these two ILs indicated that the anions interact mainly with hydrogen atoms from both the imidazolium ring and the methyl chain; the bromide anion displays twice the hydrogen coordination number than the oxygen atoms from the trifluoroacetate anion. Furthermore, Non-Covalent interactions (NCI index), determined by DFT calculations, revealed that some hydrogen bonds in the [C4mim][Br] IL displayed similar strength to those in the [C4mim][CF3COO] IL, in spite of the shorter O--H distances found in the latter IL. The majority of the calculated transport properties presented reasonable agreement with the experimental available data. Nonetheless, the self-diffusion coefficients determined in this work are under-estimated with respect to experimental values; however, by escalating the electrostatic atomic charges for the anion and cation to ±0.8e, only for this property, a remarkable improvement was obtained. Experimental evidence was recovered for most of the calculated properties and to the best of our knowledge, some new predictions were done mainly in thermodynamic states where data are not available. To validate the FF, developed previously within the research group, dynamic properties were also evaluated for a series of ILs such as [C4mim][PF6], [C4mim][BF4], [C4mim][OMs], and [C4mim][NTf2] ILs.
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Affiliation(s)
- Joel Sánchez-Badillo
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Zona Universitaria Av. Manuel Nava No. 6 San Luis Potosí C.P. 78210 Mexico
| | - Marco Gallo
- Tecnológico Nacional de México/ITCJ Av. Tecnológico No. 1340, Cd. Juárez Chihuahua C.P. 32500 Mexico
| | - Ricardo A Guirado-López
- Instituto de Física "Manuel Sandoval Vallarta", Universidad Autónoma de San Luis Potosí Álvaro Obregón No. 64 San Luis Potosí C.P. 78000 Mexico
| | - Jorge López-Lemus
- Facultad de Ciencias, Universidad Autónoma del Estado de México Toluca Estado de México C.P. 50000 Mexico
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Horton JT, Allen AEA, Dodda LS, Cole DJ. QUBEKit: Automating the Derivation of Force Field Parameters from Quantum Mechanics. J Chem Inf Model 2019; 59:1366-1381. [DOI: 10.1021/acs.jcim.8b00767] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Joshua T. Horton
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Alice E. A. Allen
- TCM Group, Cavendish Laboratory, 19 JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Leela S. Dodda
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Daniel J. Cole
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
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33
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Doherty B, Acevedo O. OPLS Force Field for Choline Chloride-Based Deep Eutectic Solvents. J Phys Chem B 2018; 122:9982-9993. [DOI: 10.1021/acs.jpcb.8b06647] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brian Doherty
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
| | - Orlando Acevedo
- Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States
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34
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Saielli G. Computational Spectroscopy of Ionic Liquids for Bulk Structure Elucidation. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800084] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Giacomo Saielli
- CNR Institute on Membrane Technology; Unit of Padova; Via Marzolo 1-35131 Padova Italy
- Department of Chemical Sciences; University of Padova; Via Marzolo 1-35131 Padova Italy
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