Determination and Prediction for the Polarity of Ionic Liquids

Guan, Wei; Chang, Nai Wen; Yang, Lili; Bu, Xiaoxue; Wei, Jie; Liu, Qing-Shan

doi:10.1021/acs.jced.7b00082

Cited by 14 publications

(3 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be observed that the enthalpy of vaporization obtained from the data of Ravula et al [78] is comparable to the one from the data of Shahbaz et al [77] for ChClG, while it is much larger in the case of ChClU. The computed enthalpies of vaporization from MD are larger than the enthalpies of vaporization found in literature for many ionic liquids [11,17,22,[87][88][89]. The computed SPs are also larger than the ones reported for ILs [8,10,11,13,16,22,88], indicating a more polar nature of the DESs compared to most ILs, when the vaporizing entity is assumed to be a DES cluster.…”

Section: Sps From Vaporization Energysupporting

confidence: 59%

Computing solubility parameters of deep eutectic solvents from Molecular Dynamics simulations

Salehi

Ramdin

Moultos

et al. 2019

Fluid Phase Equilibria

View full text Add to dashboard Cite

The solubility parameter (SP) of a solvent is a key property that measures the polarity and quantifies the 'like-dissolves-like' principle, which is an important rule in chemistry for screening solvents for separation processes. It is challenging to experimentally obtain solubility parameters of non-volatile solvents like ionic liquids (ILs), deep eutectic solvents (DESs), and polymers. Here, Molecular Dynamics (MD) simulations have been used to compute the Hildebrand and Hansen solubility parameters of DESs, which are green solvents with potential applications in many different fields. The results from MD simulations are compared with limited available experimental data and commonly used SP correlations for non-volatile solvents. Very limited information is available in literature for the vapor phase composition of DESs. Solubility parameters are computed based on the vaporization of hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) components of the DESs as well as clusters, consisting of HBD and HBA components. The relatively large SPs computed from MD indicate that the investigated choline chloride-based DESs are polar solvents. The values of SPs are not significantly affected by temperature. A comparison of vaporization enthalpies of HBD, HBA and clusters from the DES mixture suggests that it is more likely for HBD molecules to vaporize from the DES mixture and dominate the vapor phase.

show abstract

Section: Sps From Vaporization Energysupporting

confidence: 59%

Computing solubility parameters of deep eutectic solvents from Molecular Dynamics simulations

Salehi

Ramdin

Moultos

et al. 2019

Fluid Phase Equilibria

View full text Add to dashboard Cite

show abstract

“…The relative permittivity of ILs has been obtained from the microwave dielectric spectra, and the values are remarkably lower than those of common polar molecular solvents, which often lead to confusion. , Since the molar electronic transition energy of the longest-wavelength Vis absorption band of betaine dye no. 30 [ E T (30) value] exhibits a good, generally linear correlation with a large number of other solvent-sensitive spectral parameters, such as some UV–vis absorption bands, the hyperfine coupling constant ( A N ), and the Stokes shift of fluorescence spectra in molecular solvents, , and also has the same trend with Z-, Ω-, and S-values as well as many thermodynamic and dynamic data, − E T (30) values are widely used as a polarity parameter for ILs. − Reichardt et al have collected the E T (30) values of nearly 210 ILs before. Therefore, in this work, E T (30) was chosen as a standard and generally applicable solvent polarity parameter of ILs …”

Section: Introductionmentioning

confidence: 99%

The Polarity of Ionic Liquids: Relationship between Relative Permittivity and Spectroscopic Parameters of Probe

Wang

Zhang

Yao

et al. 2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Polarity is one of the most important properties of ionic liquids (ILs) and an essential requirement when choosing an IL for a specific industrial application. Up to now, several empirical solvent polarity scales, such as Hildebrand solubility parameter, relative permittivity, the electronic transition energy of the longest-wavelength Vis absorption band of betaine dye no. 30 (E T (30) value) and the hyperfine coupling constant (A N ) etc. have been applied to ILs to provide quantitative evaluation of the polarity of ILs. Among them, the E T (30) value is widely used to reflect the polarity of ILs, however, it cannot be determined for opaque solvents or for solvents in which betaine dye no. 30 is insoluble. To broaden its scope of application and uniform the polarity standard, many approaches were used to predict the values of E T (30). Herein, we managed to apply a modified semiempirical reaction field of molecular solvents to predict the E T (30) and A N values of spin probe in ILs. Based on the experimental and estimated E T (30) values of 791 data entries, 240 ILs, 108 cations, and 34 anions of ILs, an "overall" polarity sequence of ILs can be obtained: primary, secondary, and tertiary alkylammonium salts > heterocyclic salts > quaternary alkylammonium salts ≈ phosphonium salts ≈ guanidinium salts.

show abstract

“…Characterization of solvent-solute interactions is a non-trivial task, and many different techniques have been used for this purpose. These include but are not limited to, 1 H and 13 C NMR [14], UV/vis absorption and fluorescence [15][16][17][18][19], octanol-water partition [20], chromatography [20][21][22] and analyzing the solvent effect based on standard chemical reactions [23][24][25][26][27][28]. Physical properties can also provide insight into the macroscopic polar properties of a solvent through for example, refractive index and molar refractivity [29,30], but do not provide detail on intermolecular electrostatic and polarization forces between the solute and solvent.…”

Section: Introductionmentioning

confidence: 99%

Exploring Solvation Properties of Protic Ionic Liquids by Employing Solvatochromic Dyes and Molecular Dynamics Simulation Analysis

Brown,

Christofferson,

Drummond

et al. 2024

Liquids

View full text Add to dashboard Cite

Solvation properties are key for understanding the interactions between solvents and solutes, making them critical for optimizing chemical synthesis and biochemical applications. Designable solvents for targeted optimization of these end-uses could, therefore, play a big role in the future of the relevant industries. The tailorable nature of protic ionic liquids (PILs) as designable solvents makes them ideal candidates. By alteration of their constituent structural groups, their solvation properties can be tuned as required. The solvation properties are determined by the polar and non-polar interactions of the PIL, but they remain relatively unknown for PILs as compared to aprotic ILs and their characterization is non-trivial. Here, we use solvatochromic dyes as probe molecules to investigate the solvation properties of nine previously uncharacterized alkyl- and dialkylammonium PILs. These properties include the Kamlet–Aboud–Taft (KAT) parameters: π* (dipolarity/polarizability), α (H-bond acidity) and β (H-bond basicity), along with the ET(30) scale (electrophilicity/polarizability). We then used molecular dynamics simulations to calculate the radial distribution functions (RDF) of 21 PILs, which were correlated to their solvation properties and liquid nanostructure. It was identified that the hydroxyl groups on the PIL cation increase α, π* and ET(30), and correspondingly increase the cation–anion distance in their RDF plots. The hydroxyl group, therefore, reduces the strength of the ionic interaction but increases the polarizability of the ions. An increase in the alkyl chain length on the cation led to a decrease in the distances between cations, while also increasing the β value. The effect of the anion on the PIL solvation properties was found to be variable, with the nitrate anion greatly increasing π*, α and anion–anion distances. The research presented herein advances the understanding of PIL structure–property relationships while also showcasing the complimentary use of molecular dynamics simulations and solvatochromic analysis together.

show abstract

Determination and Prediction for the Polarity of Ionic Liquids

Cited by 14 publications

References 89 publications

Computing solubility parameters of deep eutectic solvents from Molecular Dynamics simulations

Computing solubility parameters of deep eutectic solvents from Molecular Dynamics simulations

The Polarity of Ionic Liquids: Relationship between Relative Permittivity and Spectroscopic Parameters of Probe

Exploring Solvation Properties of Protic Ionic Liquids by Employing Solvatochromic Dyes and Molecular Dynamics Simulation Analysis

Contact Info

Product

Resources

About