Extensive Evaluation of the Conductor-like Screening Model for Real Solvents Method in Predicting Liquid–Liquid Equilibria in Ternary Systems of Ionic Liquids with Molecular Compounds

2018 ◽  
Vol 122 (14) ◽  
pp. 4016-4028 ◽  
Author(s):  
Kamil Paduszyński
Author(s):  
Roberto I. Canales ◽  
Michael J. Lubben ◽  
Maria Gonzalez-Miquel ◽  
Joan F. Brennecke

Carbon dioxide has been shown to be an effective antisolvent gas for separating organic compounds from ionic liquids (ILs) by inducing a liquid–vapour to liquid–liquid–vapour transition. Using carbon dioxide, toluene can be separated from imidazolium, phosphonium and pyridinum cation-based ILs with the bis(trifluoromethylsulfonyl)imide anion, which is relatively hydrophobic and has a high toluene solubility. A new IL with relatively low viscosity is tested here for the same toluene separation process: 1- n -butylthiolanium bis(trifluoromethylsulfonyl)imide. Carbon dioxide solubility in binary and ternary systems containing toluene and 1- n -butylthiolanium bis(trifluoromethylsulfonyl)imide is measured at 298.15 and 313.15 K up to 7.4 MPa. Solubility behaviour in this IL is similar to imidazolium-based ILs with the same anion. However, phase split pressures are lower when 1- n -butylthiolanium bis (trifluoromethylsulfonyl)imide is used instead of 1- n -hexyl-3-methylimidazolium bis(trifluoromethylsu- lfonyl)imide at the same conditions of temperature and initial composition of toluene in the IL. Solubility data are modelled with the conductor-like screening model for real solvents combined with the Soave–Redlich–Kwong equation of state, which provides good qualitative results.


2019 ◽  
Author(s):  
Kateryna Goloviznina ◽  
José N. Canongia Lopes ◽  
Margarida Costa Gomes ◽  
Agilio Padua

A general, transferable polarisable force field for molecular simulation of ionic liquids and their mixtures with molecular compounds is developed. This polarisable model is derived from the widely used CL\&P fixed-charge force field that describes most families of ionic liquids, in a form compatible with OPLS-AA, one of the major force fields for organic compounds. Models for ionic liquids with fixed, integer ionic charges lead to pathologically slow dynamics, a problem that is corrected when polarisation effects are included explicitly. In the model proposed here, Drude induced dipoles are used with parameters determined from atomic polarisabilities. The CL\&P force field is modified upon inclusion of the Drude dipoles, to avoid double-counting of polarisation effects. This modification is based on first-principles calculations of the dispersion and induction contributions to the van der Waals interactions, using symmetry-adapted perturbation theory (SAPT) for a set of dimers composed of positive, negative and neutral fragments representative of a wide variety of ionic liquids. The fragment approach provides transferability, allowing the representation of a multitude of cation and anion families, including different functional groups, without need to re-parametrise. Because SAPT calculations are expensive an alternative predictive scheme was devised, requiring only molecular properties with a clear physical meaning, namely dipole moments and atomic polarisabilities. The new polarisable force field, CL\&Pol, describes a broad set set of ionic liquids and their mixtures with molecular compounds, and is validated by comparisons with experimental data on density, ion diffusion coefficients and viscosity. The approaches proposed here can also be applied to the conversion of other fixed-charged force fields into polarisable versions.<br>


2021 ◽  
Vol 105 ◽  
pp. 103210
Author(s):  
Mariusz Zalewski ◽  
Tomasz Krawczyk ◽  
Agnieszka Siewniak ◽  
Aleksander Sobolewski

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 13
Author(s):  
Khairulazhar Jumbri ◽  
Mohd Azlan Kassim ◽  
Normawati M. Yunus ◽  
Mohd Basyaruddin Abdul Rahman ◽  
Haslina Ahmad ◽  
...  

This work presents a molecular level investigation on the nature and mode of binding between imidazolium-based ionic liquids (ILs) ([Cnbim]Br where n = 2, 4, 6) with calf thymus DNA. This investigation offers valuable insight into the mechanisms of interactions that can affect the structural features of DNA and possibly cause the alteration or inhibition of DNA function. To expedite analysis, the study resorted to using molecular docking and COnductor like Screening MOdel for Real Solvents (COSMO-RS) in conjunction with fluorescence spectroscopic data for confirmation and validation of computational results. Both the fluorescence and docking studies consistently revealed a weak interaction between the two molecules, which corresponded to the binding energy of a stable docking conformation in the range of −5.19 to −7.75 kcal mol−1. As predicted, the rod-like structure of imidazolium-based ILs prefers to bind to the double-helix DNA through a minor groove. Interestingly, the occurrence of T-shape π-π stacking was observed between the amine group in adenine that faces the aromatic ring of imidazole. In addition, data of COSMO-RS for the interaction of individual nucleic acid bases to imidazolium-based ILs affirmed that ILs showed a propensity to bind to different bases, the highest being guanine followed by cytosine, thymine, uracil, and adenine.


Sign in / Sign up

Export Citation Format

Share Document