Force Field Development and Liquid State Simulations on Ionic Liquids

Andrade, Jones de; Böes, Elvis S.; Stassen, Hubert

doi:10.1021/bk-2005-0901.ch009

Cited by 10 publications

(5 citation statements)

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“…A number of force fields for RTILs, 19,22,[31][32][33][34][35][36][37][38][39][40][41][42] including [BMIM][BF 4 ], have been suggested during the last decade, covering a broad spectrum of species. Both empirical FFs and direct ab initio calculations of the ion pairs were extensively used to derive structure, dynamics, and energetic properties 18,19,22,31,32,[43][44][45][46][47] of pure RTILs and certain mixtures of practical interest.…”

Section: Force Fieldsmentioning

confidence: 99%

A new force field model of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and acetonitrile mixtures

Chaban

Prezhdo

2011

Phys. Chem. Chem. Phys.

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Recently, we introduced a new force field (FF) to simulate transport properties of imidazolium-based room-temperature ionic liquids (RTILs) using a solid physical background. In the present work, we apply this FF to derive thermodynamic, structure, and transport properties of the mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF(4)], and acetonitrile (ACN) over the whole composition range. Three approaches to derive a force field are formulated based on different treatments of the ion-ion and ion-molecule Coulomb interactions: unit-charge, scaled-charge and floating-charge approaches. The simulation results are justified with the help of experimental data on specific density and shear viscosity for these mixtures. We find that a phenomenological account (particularly, a simple scaled-charge model) of electronic polarization leads to the best-performing model. Remarkably, its validity does not depend on the molar fraction of [BMIM][BF(4)] in the mixture. The derived FF is so far the first molecular model which is able to simulate all transport properties of the mixtures, comprising RTIL and ACN, fully realistically.

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Section: Force Fieldsmentioning

confidence: 99%

A new force field model of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and acetonitrile mixtures

Chaban

Prezhdo

2011

Phys. Chem. Chem. Phys.

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“…Although atomistic simulations of RTILs [19][20][21][22][23][24][25][26][27][28][29][30][31] were intensively carried out during the last decade, there is still a significant problem associated with most of the existing force fields (FF) [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] . All non-polarizable FFs for classical molecular dynamics (MD) simulation, derived using the conventional procedures with electrostatic charges on the interaction sites of cations and anions computed separately, greatly underestimate ionic dynamics.…”

Section: Introductionmentioning

confidence: 99%

Polarizability versus mobility: atomistic force field for ionic liquids

Chaban

2011

Phys. Chem. Chem. Phys.

161

183

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Based on classical molecular dynamics simulations, we discuss the impact of Coulombic interactions on a comprehensive set of properties of room temperature ionic liquids (RTILs) containing 1,3-dimethylimidazolium (MMIM + ), N-butylpyridinium (BPY + ), and bis(trifluoromethane sulfonyl)imide (TFSI -) ions. Ionic transport is found to be noticeably hindered by the excessive Coulombic energy, originating from the neglect of electronic polarization in the condensed phase of these RTILs. Starting from the models, recently suggested by Lopes and Padua, we show that realistic ionic dynamics can be achieved by the uniform scaling of electrostatic charges on all interaction sites. The original model systematically overestimates density and heat of vaporization of RTILs. Since density linearly depends on charge scaling, it is possible to use it as a convenient beacon to promptly derive a correct scaling factor. Based on the simulations of [BPY][TFSI] and [MMIM][TFSI] over a wide temperature range, we conclude that suggested technique is feasible to greatly improve quality of the already existing non-polarizable FFs for RTILs.

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“…Molecular dynamics simulations where all solute and solvent species are represented at the molecular level provide important insights into the structure and solvation properties of liquids . Concerning ILs, most simulations concentrated so far on the neat liquids − or their mixtures with e.g. water, SC-CO 2 , small organic molecules or organic liquids. − Our group initiated MD studies on the solvation of alkali and alkaline earth cations , and their complexes with macrocylic ligands, and trivalent lanthanides, actinides, ,,− focusing on the uranyl and uranium halo complexes.…”

Section: Introductionmentioning

confidence: 99%

Chloride Complexation by Uranyl in a Room Temperature Ionic Liquid. A Computational Study

Chaumont

Wipff

2008

J. Phys. Chem. B

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The stepwise addition of 1 to 4 Cl(-) anions to the uranyl cation has been studied via potential of mean force (PMF) calculations in the [BMI][Tf 2N] ionic liquid based on the 1-butyl-3-methylimidazolium cation (BMI(+)) and the bis(trifluoromethylsulfonyl)imide anion (Tf2N(-)). According to these calculations, the four Cl(-) complexation reactions are favored and UO2Cl4(2-) is the most stable chloride complex in [BMI][Tf2N]. The solvation of the different chloro-complexes is found to evolve from purely anionic (ca. 5 Tf2N(-) ions around UO2(2+)) to purely cationic (ca. 8.5 BMI (+) cations around UO2Cl4(2-)), with onion-type alternation of solvent shells. We next compare the solvation of the UO2Cl4(2-) complex to its reduced analogue UO2Cl4(3-) in the [BMI][Tf2N] and [MeBu3N][Tf2N] liquids that possess the same anion, but differ by their cation (imidazolium BMI(+) versus ammonium MeBu3N(+)). The overall solvation structure of both complexes is found to be similar in both liquids with a first solvation shell formed exclusively of solvent cations (about 9 BMI(+) cations or 7 MeBu3N(+) cations). However, a given complex is better solvated by the [BMI][Tf2N] liquid, due to hydrogen bonding interactions between Cl(-) ligands and imidazolium-ring C-H protons. According to free energy calculations, the gain in solvation energy upon reduction of UO2Cl4(2-) to UO2Cl4(3-) is found to be larger in [BMI][Tf2N] than in [MeBu3N][Tf2N], which is fully consistent with recent experimental results (Inorg. Chem. 2006, 45, 10419).

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Force Field Development and Liquid State Simulations on Ionic Liquids

Cited by 10 publications

References 0 publications

A new force field model of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and acetonitrile mixtures

A new force field model of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and acetonitrile mixtures

Polarizability versus mobility: atomistic force field for ionic liquids

Chloride Complexation by Uranyl in a Room Temperature Ionic Liquid. A Computational Study

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