Search

Ionic liquids (ILs) are known to provide stability to biomolecules. ILs are also widely used in the fields of chemical engineering, biological engineering, chemistry, and biochemistry because they facilitate enzyme catalyzed reactions and enhance their conversion rate. In this work, we have evaluated the influence of alkyl chain substitution of ammonium ILs such as diethylammonium dihydrogen phosphate (DEAP) and triethylammonium hydrogen phosphate (TEAP) for the stability and activity of the tobacco etch virus (TEV) protease. Further, we performed molecular dynamics (MD) simulations to calculate the RMSD (root mean square deviation) for TEV and TEV + ILs. Experimental and simulations results show that TEV is more stable in the presence of TEAP than DEAP. Whereas, TEV protease activity for the cleavage of fusion proteins is preserved in the presence of DEAP while lost in the presence of TEAP. Hence, DEAP IL can serve as alternative solvents for the stability of the TEV protease with preserved activity. To the best of our knowledge, this is first study to show that ILs can stabilize and maintain the TEV protease cleavage activity.

In this paper, photosensitive materials for information storage devices are presented. The polymers were prepared using surface relief-grating (SRG) fabrication with a diode-pumped solid-state (DPSS) laser of 532 nm, and the diffraction efficiency (DE) of the polymers were assessed with a low-power DPSS laser at 633 nm. However, the diffraction efficiency of the azo-functionalized epoxy-based polymer was low, even after 15 min of exposure. To improve the efficiency and reduce the time it takes for the DE measurements of the photosensitive polymer, the polymer was combined ionic liquids (ILs). Various ILs, i.e., 1-methylimidazolium chloride ([Mim]Cl) from the imidazolium family of ILs and diethylammonium dihydrogen phosphate (DEAP), triethylammonium 4-aminotoluene-3-sulfonic acid (TASA) and tributylmethylammonium methyl sulphate (TBMS) from the ammonium family of ILs, were investigated. For the first time, it was observed that DE dramatically increased the DEAP?polymer mixture in 4 min compared to the polymer (alone) and other polymer?IL mixtures. Therefore, DEAP IL could help improve the efficiency of DE measurements in a shorter time.

A mild and efficient catalytic method has been developed to synthesize 3,4-dihydropyrimidinones in high yield by one-pot three component Biginelli condensation in the presence of triethylammonium acetate (TEAA) which acts as catalyst/reaction medium. Further, we have studied the antioxidant and antibacterial activities of these synthesized 3,4-dihydropyrimidinones. All the synthesized compounds reveal the significant antioxidant properties, these properties have been studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and cupric reducing antioxidant capacity (CUPRAC) assays. In addition, to this, these compounds also show the good antibacterial activity against four human pathogenic bacteria. (C) 2014 King Saud University. Production and hosting by Elsevier B.V.

Over the past few years, polymers shown comprehensive utilization in optical devices, solar cells, sensors, and other such devices. However, the efficiency of these devices remains a problem. We have synthesized new thiophene based, lowband gap polymer, poly(2-heptadecyl-4-vinylthieno[3,4-d] [1,3] selenazole) (PHVTS) and investigated the interactions between the PHVTS and ionic liquids (ILs), in this study. We have used imidazolium- and ammonium-family ILs, and studied the interactions using various spectroscopic techniques such UV–visible, FTIR, and confocal Raman spectroscopies. Additionally, we studied surface morphology of the polymer-IL film. Spectroscopic studies show that both families of ILs can interact with the newly synthesized polymer poly(2-heptadecyl-4-vinylthieno[3,4-d] [1,3] selenazole). However, the imidazolium-family Ionic Liquid-polymer (IL-polymer) mixture films show higher conductivities than ammonium-family IL–polymer mixture films.

All-solid-state flexible supercapacitor is assembled using multi-walled carbon nanotubes (MWCNT) and ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] based gel polymer electrolyte. Flexible electrodes on polyethylene-terephthalate (PET) substrate were made by inkjet printed azide functionalized MWCNT (f-MWCNT), serving both as electrodes and charge collector. Fabricated supercapacitor f-MWCNT/gel polymer electrolyte/f-MWCNT (f-MWCNT SC) demonstrated high power and energy performance as a gel polymer electrolyte based all solid-state flexible supercapacitor. f-MWCNT SC demonstrates high specific capacitance 235 F/g at 5 mV/s in wide operating potential range of 3 V. Short relaxation time constant (Ͽo) (248 ms) with high apparent diffusion coefficient (Da) 2.25 y 10⿿8 cm2/s resulted in very high energy density 16.2 Wh/kg and power density 45 kW/kg at 1 A/g. f-MWCNT SC exhibits high flexibility and excellent cycling stability with capacity retention >90% after 5000 galvanostatic charge discharge cycles.

Conducting polymer has many applications in electronics, optical devices, sensors, and so on; however, there is still a massive scope of improvement in this area. Therefore, towards this aim, in this study, we synthesized a new thiophene-based conducting polymer, 2-heptadecyl-5-hexyl-6-(5-methylthiophen-2-yl)-4-(5-((E)-prop-1-enyl)thiophen-2-yl)-5H-pyrrolo[3,4-d]thiazole (HHMPT). Further, to increase its application, the interactions between the conducting polymer (HHMPT) and ionic liquids (ILs) were investigated by UV-Vis spectroscopy, FTIR spectroscopy, and confocal Raman spectroscopy techniques. Moreover, film roughness and conductivity of the polymer film with or without ILs were also studied. The imidazolium- and ammonium family ILs with the potential to interact with the newly synthesized conducting polymer were used. The results of the interaction studies revealed that the imidazolium family IL-polymer mixtures and ammonium family IL-polymer mixtures have almost similar conductivity at low concentration of ILs. This study provides an insight into the combined effect of a polymer and ILs and may generate many theoretical and experimental opportunities.

In this information age, different kinds of photosensitive materials have been used in the manufacture of information storage devices. But these photosensitive materials have the bane of low diffraction efficiency. In order to solve this problem, we have synthesized a novel photosensitive polymer from epoxy-based azopolymers (with three types of azochromophores). Furthermore, we have studied the interaction between this newly synthesized azopolymer and ionic liquids (ILs). For this purpose, we have used the ammonium and imidazolium families of ILs, such as diethylammonium dihydrogen phosphate (DEAP), tributylammonium methyl sulfate (TBMS), triethylammonium 4-aminotoluene-3-sulfonic acid (TASA), and 1-methylimidazolium chloride ([Mim]Cl). To investigate the molecular interaction between azopolymer and ILs, we have used the following spectroscopic methods of analysis: UV-visible spectroscopy, photoluminescence (PL) spectroscopy, Fourier transformed infrared spectroscopy (FT-IR), and confocal Raman spectroscopy. In this study, we have developed new photosensitive materials by combining polymer with ILs.

Cold atmospheric plasma and gamma rays are known to have anticancer properties, even though their specific mechanisms and roles as co-solvents during their action are still not clearly understood. Despite the use of gamma rays in cancer therapy, they have oncogenic potential, whereas this has not been observed for plasma treatment (to date). To gain a better understanding, we studied the action of dielectric barrier discharge (DBD) plasma and gamma rays on the myoglobin protein. We analyzed the secondary structure and thermodynamic properties of myoglobin after both treatments. In addition, in the last few years, ammonium ionic liquids (ILs) have revealed their important role in protein folding as co-solvents. In this work, we treated the protein with ammonium ILs such as triethylammonium methanesulfonate (TEMS) and tetrabutylammonium methanesulfonate (TBMS) and later treated this IL–protein solution with DBD plasma and gamma rays. In this study, we show the chemical and thermal denaturation of the protein after plasma and gamma treatments in the presence and absence of ILs using circular dichroism (CD) and UV-vis spectroscopy. Furthermore, we also show the influence of plasma and gamma rays on the secondary structure of myoglobin in the absence and presence of ILs or ILs + urea using CD. Finally, molecular dynamic simulations were conducted to gain deeper insight into how the ILs behave to protect the protein against the hydrogen peroxide generated by the DBD plasma and gamma rays.

A new efficient catalytic method for aza/thia-Michael addition reactions of amines/thiols with higher product yields has been developed. Combining single-walled carbon nanotubes (SWCNT) with triethylammonium hydrogen phosphate (TEAP) ionic liquid (IL) can work as a catalyst. We utilized Raman spectroscopy to gain insight into the interactions between IL and SWCNT. The interactions between SWCNT with TEAP were confirmed by the increasing intensity ratios and spectral shift in wavelength of the Raman D and G bands of SWCNT. Further, the morphology of the resulting composite materials of TEAP and SWCNT was determined by using scanning electron microscopy (SEM). Higher product yield in reduced reaction time is the key advantage of using bucky gel as a catalyst for Michael reaction.

A new catalytic method has been developed for the synthesis of aza/thia-Michael addition reactions of amines/thiols, which provide higher product yields. This catalyst is a combination of multi-walled carbon nanotubes (MWCNT) with triethylammonium hydrogen phosphate (TEAP) ionic liquid (IL), commonly referred to as bucky gel. In order to gain insight into the interactions involved between IL and MWCNT, we utilised Raman spectroscopy for our analysis. The interactions between MWCNT with TEAP were clearly evidenced by the increasing intensity ratios and spectral shift in the wavelength for the Raman D and G bands of MWCNT. The morphological studies of the resulting composite materials of TEAP and MWCNT (bucky gel) were carried out using scanning electron microscopy (SEM). The key advantage of using bucky gel as a catalyst is that higher product yield is obtained in reduced reaction time for Michael reactions.

Protein stability in ionic solution depends on the delicate balance between protein–ion and ion–ion interactions. To address the ion specific effects on the protein, we have examined the stability of myoglobin (Mb) in the presence of buffer and ammonium-based ionic liquids (ILs) (50%, v/v). Here, fluorescence and circular dichroism (CD) spectroscopy experiments are used to study the influence of ILs on structure and stability of Mb. Our experimental results reveal that more viscous ILs (sulphate or phosphate ions) are stabilizers and therefore more biocompatible for Mb structure. Surprisingly, the less viscous ILs such as acetate anion based ILs are destabilizers for the native structure of Mb. Our results explicitly elucidate that anion variation has significant influence on Mb stability efficiency than cation variation. This study provides insight into anion effects on protein stability and explains that the intrasolvent interactions can be leveraged to enhance the stability.

In this paper, we have examined the effect of temperature on the interactions between imidazolium and ammonium based ionic liquids (ILs) and the low bandgap polymer (poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole) (PHVTT)). With the aim of exploring the utility of low bandgap polymers, we have carried out the interaction studies of the polymer with the ILs and investigated the behavior of polymer in the presence of ILs as the function of temperature. Recently, ILs have attracted extensive attention in polymer sciences. In this work, we have studied the temperature dependent interactions between the protic IL (1-methylimidazolium chloride ([Mim]Cl) from imidazolium family) and aprotic ILs (tributylmethylammonium methyl sulfate ([N1444][MeSO4]) from ammonium family and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) from imidazolium family) with a low bandgap polymer. Our experimental data of UV–vis spectroscopy, photoluminescence (PL) spectroscopy, FT-IR spectroscopy, density (ρ) and speed of sound (u) as a function of temperature from 25 to 40 °C with the interval of 5 °C, clearly reveal that even at high temperature, [Bmim]Cl interacts strongly with the polymer as compared to other studied ILs.

In this work, we explore the anion effect on the thermophysical properties of protic ionic liquids (PILs) such as triethylammonium acetate [Et3NH][CH3COO] (TEAA), triethylammonium dihydrogen phosphate [Et3NH][H2PO4] (TEAP) and triethylammonium hydrogen sulfate [Et3NH][HSO4] (TEAS) with polar solvent such as dimethylsulfoxide (DMSO). To understand the molecular interactions between DMSO with ILs, densities (ρ), ultrasonic sound velocities (u) and viscosities (η) have been measured over whole range of compositions and at three temperatures, 298.15, 303.15, and 308.15 K under atmospheric pressure. A second order empirical polynomial and Arrhenius equations were used to correlate the ρ and η as function of temperature, respectively. Sound velocity mixing rules were used on experimental values. Further, the excess molar volume (VE), the deviation in isentropic compressibility (Δκs) and deviation in viscosity (Δη) were calculated using these properties. The obtained VE, Δκs and Δη values were correlated by using the Redlich–Kister polynomial equation.

Ammonium based ionic liquids (ILs) are biocompatible co-solvents that stabilize the native state of proteins. Experimentally, we have explored the stability of α-chymotrypsin (CT) in the presence of nine ILs, i.e., diethylammonium acetate (DEAA), diethylammonium hydrogen sulfate (DEAS), diethylammonium dihydrogen phosphate (DEAP), triethylammonium acetate (TEAA), triethylammonium hydrogen sulfate (TEAS), triethylammonium dihydrogen phosphate (TEAP), trimethylammonium acetate (TMAA), trimethylammonium hydrogen sulfate (TMAS), trimethylammonium dihydrogen phosphate (TMAP). Thermodynamic folding properties such as transition temperature (Tm), Gibbs free energy change of unfolding (ΔGU), enthalpy change (ΔH) and heat capacity change (ΔCp) of CT in ILs are obtained by fluorescence spectra analysis. Fluorescence and circular dichroism (CD) spectroscopy experiments were performed to probe CT stabilization and structural changes in the presence of ILs. Our experimental results suggest that the ILs act as stabilizers for the CT structure and the stability of CT depends on the structural arrangement of the ions of ILs. Our experimental results reveal that ILs (DEAA, DEAS and DEAP) having more hydrophobic ammonium cations [DEA+] are weak stabilizers for CT, while trimethyl ammonium cations [TMA+] ILs having small alkyl chain length such as TMAA, TMAS and TMAP are strong stabilizers and therefore more biocompatible for the native structure of CT.

In this article, we have reported the solubilities, apparent transfer free energies (ΔG′tr) and UV-visible absorption measurements of glycine peptides (GPs), such as glycine (Gly), diglycine (Gly2), and cyclic glycylglycine (c(GG)) in aqueous ionic liquids (ILs), bearing sulfate and phosphate anions with ammonium cation, at T = 298.15 K. Values of solubility were obtained from density (ρ) measurements of GPs in water and in aqueous ILs. The ammonium ILs such as diethylammonium hydrogen sulfate (DEAS) [(CH3CH2)2NH][HSO4], triethylammonium hydrogen sulfate (TEAS) [(CH3CH2)3NH][HSO4], and triethylammonium dihydrogen phosphate (TEAP) [(CH3CH2)3NH][H2PO4] have been used in the present study. We observed the positive values of ΔG′tr for Gly, Gly2, and c(GG) from water to ILs. These results reveal that the unfavourable interactions are dominated between ILs and the GPs. This indicates that the ammonium based ILs stabilize the GP structure. Further, we have used the ΔG′tr results to evaluate the transfer free energies (Δg′tr) contribution of the peptide backbone unit, also known as glycyl residue, (–CH2C ONH–) as function of ILs concentration. Our results suggest that all the investigated ammonium ILs are compatible with GPs and act as stabilizers for GPs structure through exclusion of ILs from GPs’ surface. Furthermore, UV-vis spectrophotometer measurements are used as evidence for the stability of GPs in aqueous ILs at T = 298.15 K.

Understanding the folding process of proteins or polypeptides in co-solvents is a fascinating and critical issue in biophysical chemistry. In recent years, ionic liquids (ILs) represent a versatility of the new class of co-solvents. To quantify the bimolecular interactions of amino acids (AA), such as l -alanine (Ala) and l -valine (Val) with biocompatible ILs, we report the apparent transfer free energies ( Δ G ′ t r ) for AA from water to aqueous solutions of six ammonium based ILs (diethylammonium acetate (DEAA), diethylammonium sulfate (DEAS), triethyl ammonium acetate (TEAA), triethylammonium sulfate (TEAS), triethylammonium dihydrogen phosphate (TEAP), and trimethylammonium acetate (TMAA)) through solubility measurements, as a function of IL concentration at 298.15 K under atmospheric pressure. Salting-out effect was found for AA in aqueous IL solutions with increasing IL concentrations. In addition, we observed positive values of Δ G ′ t r for Ala and Val from water to ILs, indicating that the interactions between ILs and AA are unfavorable. From the solubility results, we envisage that the selected ammonium based-ILs provide stability to the structure of AA. Further, the stability of AA has been studied by means of the UV–vis spectroscopy.

We report the synthesis and characterisation of a series of ammonium ionic liquids (ILs) containing acetate and sulphate anions with alkyl ammonium cation. To understand the thermophysical properties of these synthesised ILs with polar solvent N-methyl-2-pyrrolidone (NMP), precise measurements such as densities (ρ), speed of sound (u), and viscosity (η) over the entire mole fraction range have been measured at 5 K intervals within the temperature range of (298.15 to 313.15) K under atmospheric pressure. The excess molar volume (VE), the deviation in isentropic compressibility (Δκs), and deviation in viscosity (Δη) were predicted using these temperature dependence properties as a function of the concentration of ILs. The Redlich–Kister polynomial was used to correlate the results. The ILs investigated in the present work included diethylammonium acetate (DEAA) [(CH3CH2)2NH][CH3COO], triethylammonium acetate (TEAA) [(CH3CH2)3NH][CH3COO], diethylammonium hydrogen sulphate (DEAS) [(CH3CH2)2NH][HSO4], and triethylammonium hydrogen sulphate (TEAS) [(CH3CH2)3NH][HSO4]. The intermolecular interactions and structural effects were analysed on the basis of the measured and the derived properties. The information reported here in terms of ion–dipole interactions, ion-pair interactions and hydrogen bonding between ILs and NMP, elucidates the influences of ions and also the temperature effects on the thermophysical properties.

To address the molecular interactions between ionic liquids (ILs) such as trimethylammonium acetate [(CH3)3NH][CH3COO] (TMAA), trimethylammonium hydrogen sulphate [(CH3)3NH][HSO4] (TMAS), trimethylammonium dihydrogen phosphate [(CH3)3NH][H2PO4] (TMAP) and triethylammonium dihydrogen phosphate [(CH3CH2)3NH][H2PO4] (TEAP) with N-methyl-2-pyrrolidone (NMP), density (ρ), ultrasonic sound velocity (u) and viscosity (η) measurements have been performed across the entire concentration range and the wide temperature range from 298.15 to 313.15 K in steps of 5 K under ambient pressure. Further, on the basis of the measured properties, excess volumes (VE), isentropic compressibility deviations (Δκs) and viscosity deviations (Δη) were obtained for all these systems under the same experimental conditions. The results are correlated by the Redlich–Kister type equation. The results are also analysed on anion dependent phenomena and temperature influence on measured and derived properties of ILs with NMP mixtures. A qualitative analysis of molecular interactions between ILs and NMP is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding.

In this article, we present the synthesis of a series ionic liquids (ILs) having different kosmotropicity including dihydrogen phosphate ( H 2 PO 4 - ) and hydrogen sulphate ( HSO 4 - ) as anions and chaotropic cation such as alkylammonium. Here, we have investigated the biomolecular interactions and related associated structural changes of succinylated Con A (S Con A) with alkylammonium ILs by using several biophysical techniques including circular dichroism (CD) and fluorescence. The ILs studied in the present research includes diethylammonium dihydrogen phosphate [(CH3CH2)2NH+][ H 2 PO 4 - ] (DEAP), diethylammonium hydrogen sulphate [(CH3CH2)2NH+][ HSO 4 - ] (DEAS), triethylammonium dihydrogen phosphate [(CH3CH2)3NH+][ H 2 PO 4 - ] (TEAP) and triethylammonium hydrogen sulphate [(CH3CH2)3NH+][ HSO 4 - ] (TEAS). We observed that all ILs have a dominant contribution to the stabilization of the native structure of the S Con A. Our experimental results distinctly demonstrate that the long alkyl chain IL TEAP is a strong stabilizer and therefore more biocompatible for S Con A. Furthermore, the results reveal that phosphate anions of ILs are strong stabilizers and acted as effective refolding enhancers for thermally denatured protein structure, whereas the protein was not refolded in the sulphate anions of ILs. These findings suggest a new generation of protein stabilizers that can be applied to other protein folding studies and biological systems.

To quantify the biomolecular interactions of protein functional groups with biocompatible ionic liquids (ILs), transfer free energies ( Δ G tr ′ ) of model compounds from water to aqueous ILs solutions have been determined from the solubility measurements, as a function of ILs concentration at T = 298.15 K under atmospheric pressure. The aqueous systems investigated contain amino acids of zwitterionic glycine peptides: glycine (Gly), diglycine (Gly2), and cyclic glycylglycine (c(GG)) with ILs of diethylammonium acetate ([Et2NH][CH3COO], DEAA), triethylammonium acetate ([Et3NH][CH3COO], TEAA), and trimethylammonium acetate ([Me3NH][CH3COO], TMAA). It was found that the solubility of model compounds in aqueous IL solutions decreases with increasing IL concentration (salting-out effect). We observed positive values of Δ G tr ′ for Gly, Gly2, and c(GG) from water to ILs, indicating that the interactions between ILs and protein surface are unfavourable, which leads to stabilization of the native structure of amino acids. Moreover, our experimental data is used to determine transfer free energies ( Δ g tr ′ ) of the peptide backbone unit (–CH2C ONH–) from water to IL solutions. These results explicitly elucidate that all alkyl ammonium ILs acted as stabilizers for tested model compounds through the exclusion of ILs from surface of model compounds and also reflect the effect of alkyl chain on the stability of protein model compounds. To obtain the mechanism events of the ILs role in enhancing the stability of the model compounds structure, we further studied the UV–vis spectrum analysis.

To understand the molecular interactions between newly synthesized ammonium ionic liquids (ILs) and highly polar solvent dimethylsulfoxide (DMSO), precise measurements such as densities ( ρ ), ultrasonic sound velocities ( u ) and viscosities ( η ) have been performed over the whole composition range at temperature ranging from 298.15 to 308.15 K and at atmospheric pressure. The ILs investigated in the present study included diethyl ammonium acetate ([Et 2 NH][CH 3 COO], DEAA) and triethyl ammonium acetate ([Et 3 NH][CH 3 COO], TEAA). Further, to gain some insight into the nature of molecular interactions in these mixed solvents, we predicted the excess molar volume ( V E ), the deviation in isentropic compressibilities (Δ K s ) and deviation in viscosity (Δ η ) as a function of the concentration of IL using the measured properties of ρ , u and η , respectively. Redlich–Kister polynomial was used to correlate the results. The intermolecular interactions and structural effects were analyzed on the basis of the measured and the derived properties. A qualitative analysis of the results is discussed in terms of the ion–dipole, ion–pair interactions, and hydrogen bonding between ILs and DMSO molecules and their structural factors.

In this article, we present densities (ρ), ultrasonic sound velocities (u) and viscosities (η) for the binary systems of the highly polar compound dimethylsulfoxide (DMSO) with ionic liquids (ILs) over the whole composition range at temperature ranging from 298.15 to 328.15 K under atmospheric pressure. The ILs investigated in the present study included diethyl ammonium hydrogen sulfate ([Et2NH][HSO4], DEAS) is an ammonium salt (protic IL) and 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) is an imidazolium salt (aprotic IL). Further, to gain some insight into the several aggregations of molecular interactions present in these mixed solvents, we predicted the excess molar volume (VE), the deviation in isentropic compressibilities (ΔKs) and deviation in viscosity (Δη) as a function of the concentration of IL using the measured properties of ρ, u and η, respectively. Redlich–Kister polynomial was used to correlate the results. The intermolecular interactions and structural effects were analyzed on the basis of the measured and the derived properties. A qualitative analysis of the results is discussed in terms of the ion–dipole, ion-pair interactions, and hydrogen bonding between ILs and DMSO molecules and their structural factors. Comparison of these properties of DMSO with ILs explicitly elucidates the influence of ions and also the temperature effects on the thermophysical properties.

In view the of wide scope of structural information of biomolecules in biocompatible ionic liquids (ILs) in various applications including chemical and biochemical, it is essential to study the productive preferential interactions between biological macromolecules and biocompatible ILs. We have therefore explored the stability and activity of α-chymotrypsin (CT) in the presence of five ILs from different families, such as triethyl ammonium acetate (TEAA), triethyl ammonium phosphate (TEAP) from ammonium salts, 1-benzyl-3-methylimidazolium chloride ([Bzmim][Cl]), 1-benzyl-3-methylimidazolium tetrafluoroborate ([Bzmim][BF(4)]) from imidazolium salts and tetra-butyl phosphonium bromide (TBPBr) from phosphonium families. Circular dichroism (CD) and UV-vis spectrophotometer experiments were used to study CT stabilization by ILs, related to the associated structural changes and enzyme activity studies, respectively. We observed that all ILs have a dominant contribution to the stabilization of CT. The stability and activity of CT depends on the structural arrangement of the ions of ILs. Our experimental results explicitly elucidate that more hydrophobic imidazolium and phosphonium cations carrying longer alkyl chains of ILs ([Bzmim][Cl], [Bzmim][BF(4)] and TBPBr) were weak stabilizers for CT, while small alkyl chain molecules of triethyl ammonium salts (TEAA and TEAP) are strong stabilizers and therefore more biocompatible for CT stability. Our CD and NMR measurements reveal that TEAA is a refolding additive for CT from a quenched thermal unfolded enzyme structure.

In view of the wide scope of molecular interactions between the highly polar compound of N,N-dimethylformamide (DMF) and ammonium ionic liquids (ILs), we have measured thermophysical properties such as densities (ρ) and ultrasonic sound velocities (u) over the whole composition range at temperatures ranging from 25 to 50 °C under atmospheric pressure. To gain some insight into the several aggregations of molecular interactions present in these mixed solvents, we predicted the excess molar volume (V(E)) and the deviations in isentropic compressibilities (ΔK(s)) as a function of the concentration of IL. These results are fitted to the Redlich-Kister polynomials. The materials investigated in the present study included the hydroxide series of ammonium ILs of tetramethylammonium hydroxide [(CH(3))(4)N][OH] (TMAH), tetraethylammonium hydroxide [(C(2)H(5))(4)N][OH] (TEAH), and tetrapropylammonium hydroxide [(C(2)H(7))(4)N][OH] (TPAH). The intermolecular interactions and structural effects were analyzed on the basis of the measured and the derived properties. A qualitative analysis of the results is discussed in terms of the ion-dipole and ion-pair interactions, and hydrogen bonding between ILs and DMF molecules and their structural factors.

An incredibly elementary procedure for the effective synthesis of 1,5-benzodiazepine derivatives using triethyl ammonium acetate (TEAA) [Et3NH][CH3COO] ionic liquid has been developed. TEAA was found to be practical, inexpensive, reusable and has a simple work-up procedure, which is absent in other catalyst. The role of TEAA as the reaction medium as well as the catalyst has shown the benefits of the use of TEAA in organic synthesis. The effect of [Et3NH][CH3COO] on the synthesis of 1,5-benzodiazepine derivatives has been studied and results are provided herein.

A new, highly efficient, inexpensive, recyclable, mild, convenient, and green protocol for chemoselective aza/thia-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using triethylammonium acetate (TEAA) ionic liquid was developed. The catalyst can be recycled ten times and obviate the need for toxic and expensive catalysts.

The presence of salts in biological solution can affect the activity of the reactive species (RS) generated by plasma and so they can also have an influence on the plasma-induced sterilization. In this work, we assess the influence that diethylammonium dihydrogen phosphate (DEAP), an ionic liquid (IL) and sodium chloride (NaCl), an ionic salt (IS), have on the structural changes in hemoglobin (Hb) in the presence of RS generated using dielectric barrier discharge (DBD) plasma in the presence of various gases [O2, N2, Ar, He, NO (10%) + N2 and Air]. We carry out fluorescence spectroscopy to verify the generation of •OH with or without the presence of DEAP IL and IS and we use electron spin resonance (ESR) to check the generation of H• and •OH. In addition, we verified the structural changes in the Hb structure after treatment with DBD in presence and absence of IL and IS. We then assessed the structural stability of the Hb in the presence of IL and IS by using molecular dynamic (MD) simulations. Our results indicate that the IL has a strong effect on the conservation of the Hb structure relative to that of IS against RS generated by plasma.

Experimental densities (ρ), ultrasonic sound velocities (u), viscosities (η), and refractive indices (n(D)) of binary mixtures of ammonium-based ionic liquids (ILs) such as diethylammonium acetate (DEAA) [(CH3CH2)2NH][CH3COO], triethylammonium acetate (TEAA) [(CH3CH2)3NH][CH3COO], diethylammonium hydrogen sulfate (DEAS) [(CH3CH2)2NH][HSO4], triethylammonium hydrogen sulfate (TEAS) [(CH3CH2)3NH][HSO4], trimethylammonium acetate (TMAA) [(CH3)3NH][CH3COO], and trimethylammonium hydrogen sulfate (TMAS) [(CH3)3NH][HSO4] with water are reported over the wide composition range at 25 °C under atmospheric pressure. The excess molar volumes (V(E)), deviation in isentropic compressibilities (Δκ(s)), deviation in viscosities (Δη) and deviation in refractive indices (Δn(D)) are calculated from experimental values and are correlated by Redlich-Kister polynomial equations. The V(E) and Δκ(s) values for the aforesaid systems are negative over the entire composition range while the Δη and Δn(D) values are positive under the same experimental conditions. The intermolecular interactions and structural effects were analyzed on the basis of measured and derived properties. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions and hydrogen bonding between ILs and water. Furthermore, the hydrogen bonding features between ILs with water were analyzed by using a molecular modeling program with the help of HyperChem7.

In this work, we have explored the thermophysical properties of tetraalkylammonium hydroxide ionic liquids (ILs) such as tetrapropylammonium hydroxide (TPAH) and tetrabutylammonium hydroxide (TBAH) with isomers of butanol (1-butanol, 2-butanol and 2-methyl-2-propanol) within the temperature range 293.15-313.15 K, with interval of 5 K and over the varied concentration range of ILs. The molecular interactions between ILs and butanol isomers are essential for understanding the function of ILs in related measures and excess functions are sensitive probe for the molecular interactions. Therefore, we calculated the excess molar volume (V-E) and the deviation in isentropic compressibility (Delta kappa(s)) using the experimental values such as densities (rho) and ultrasonic sound velocities (u) that are measured over the whole compositions range at five different temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K) and atmospheric pressure. These excess functions were adequately correlated by using the Redlich-Kister polynomial equation. It was observed that for all studied systems, the V-E and Delta kappa(s) values are negative for the whole composition range at 293.15 K. And, the excess function follows the sequence: 2-butanol>1-butanol>2-methyl-2-propanol, which reveals that (primary or secondary or tertiary) position of hydroxyl group influence the magnitude of interactions with ILs. The negative values of excess functions are contributions from the ion-dipole interaction, hydrogen bonding and packing efficiency between the ILs and butanol isomers. Hence, the position of hydroxyl group plays an important role in the interactions with ILs. The hydrogen bonding features between ILs and alcohols were analysed using molecular modelling program by using HyperChem 7.

In this work, we explore and compare the role of the ion effect on the thermophysical properties of two families of ionic liquids (ILs), namely, tetra-alkyl ammonium cation [R4N](+) with hydroxide [OH](-) anion and 1-alkyl-3-methyl imidazolium cation [amim](+) with different anions (chloride, methyl sulfate, and tetrafluoroborate), with polar solvent such as dimethylsulfoxide (DMSO) in the temperature range from 25 to 40 °C and over the whole concentration range of ILs. Two families of ILs, namely, tetramethyl ammonium hydroxide [(CH3)4N][OH] (TMAH), tetraethyl ammonium hydroxide [(C2H5)4N][OH] (TEAH), tetrapropyl ammonium hydroxide [(C3H7)4N][OH] (TPAH), and tetrabutyl ammonium hydroxide [(C4H9)4N][OH] (TBAH) from ammonium-based ILs and 1-ethyl-3-methylimidazolium chloride [Emim][Cl], 1-ethyl-3-methylimidazolium methylsulfate [Emim][MeSO4], 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4], and 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) from imidazolium family of ILs, are used in the present study. To address the molecular interactions of ILs with DMSO, densities (ρ), ultrasonic sound velocities (u), and viscosities (η) have been measured over the entire composition range and at four temperatures, 25, 30, 35, and 40 °C, under atmospheric pressure. From these experimental data, the excess molar volume (V(E)), the deviation in isentropic compressibility (Δκs), and the deviation in viscosity (Δη) were calculated and were adequately correlated by using the Redlich-Kister polynomial equation. The measured and predicted data were interpreted on the basis of intermolecular interactions and structural effects between like and unlike molecules upon mixing. The hydrogen-bonding features between ammonium-based ILs and DMSO were analyzed using molecular modeling program by HyperChem 7.

In this paper, we have examined the effect of ammonium and imidazolium based ionic liquids (ILs) on the stability and activity of proteolytic enzyme alpha-chymotrypsin (CT) in the presence of cold atmospheric pressure plasma jet (APPJ). The present work aims to illustrate the state of art implementing the combined action of ILs and APPJ on the enzyme stability and activity. Our circular dichroism (CD), fluorescence and enzyme activity results of CT have revealed that buffer and all studied ILs {triethylammonium hydrogen sulphate (TEAS) from ammonium family and 1-butyl-3-methyl imidazolium chloride ([Bmim][Cl]), 1-methylimidazolium chloride ([Mim][Cl]) from imidazolium family} are notable to act as protective agents against the deleterious action of the APPJ, except triethylammonium dihydrogen phosphate (TEAP) ammonium IL. However, TEAP attenuates strongly the deleterious action of reactive oxygen species (ROS) created by APPJ on native structure of CT. Further, TEAP is able to retain the enzymatic activity after APPJ exposure which is absent in all the other systems. This study provides the first combined effect of APPJ and ILs on biomolecules that may generate many theoretical and experimental opportunities. Through this methodology, we can utilise both enzyme and plasma simultaneously without affecting the enzyme structure and activity on the material surface; which can prove to be applicable in various fields.

In recent years, ionic liquids (ILs) represent a new class of biocompatible co-solvents for biomolecules. In this work, we report the apparent transfer free energies ( ΔG'tr) for six amino acids (AA) from water to aqueous solutions of six ammonium based ILs (diethylammonium acetate (DEAA), diethylammonium sulfate (DEAS), triethyl ammonium acetate (TEAA), triethylammonium sulfate (TEAS), triethylammonium dihydrogen phosphate (TEAP), and trimethylammonium acetate (TMAA)) through solubility measurements, as a function of IL concentration at 298.15 K under atmospheric pressure. Salting-out effect was found for AA in aqueous IL solutions with increasing IL concentrations. In addition, we observed positive values of Δ G'tr for AA from water to ILs, indicating that the interactions between ILs and AA are unfavorable. From the obtained results, we found that the selected ammonium based ILs act as stabilizers for the structure of AA.

In this paper, we have examined the conductivity and interaction studies of ammonium and imidazolium based ionic liquids (ILs) with the newly synthesised low bandgap polymer (Poly(2-heptadecyl-4-vinylthieno[3,4-d] thiazole) (PHVTT)). Use of low bandgap polymers is the most suitable way to harvest a broader spectrum of solar radiations for solar cells. But, still there is lack of most efficient low bandgap polymer. In order to solve this problem, we have synthesised a new low bandgap polymer and investigated its interaction with the ILs to enhance its conductivity. ILs may undergo almost unlimited structural variations; these structural variations have attracted extensive attention in polymer studies. The aim of present work is to illustrate the state of art progress of implementing the interaction of ILs (protic and aprotic ILs) with newly synthesised low bandgap polymer. In addition to this, our UV-Vis spectroscopy, confocal Raman spectroscopy and FT-IR spectroscopy results have revealed that all studied ILs (tributylmethylammonium methyl sulfate ([N-1444][MeSO4] from ammonium family) and 1-methylimidazolium chloride ([Mim]Cl, and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl from imidazolium family) have potential to interact with polymer. Our semi empirical calculation with help of Hyperchem 7 shows that protic IL ([Mim]Cl) interacts strongly with the low bandgap polymer through the H-bonding. Further, protic ILs shows enhanced conductivity than aprotic ILs in association with low bandgap polymer. This study provides the combined effect of low bandgap polymer and ILs that may generate many theoretical and experimental opportunities.

Four ammonium and imidazolium ionic liquids (ILs) have been synthesized and screened against the T98G cell line (brain cancer) and HEK normal cells. Treatment induced metabolic cell death (MTT), growth inhibition, clonogenic inhibition were studied as cellular response parameters. Treatment with ILs enhanced growth inhibition and cell death in a concentration dependent manner in both the T98G and HEK cell lines. At higher concentrations (>0.09 mg/mL) the cytotoxic effects of the ILs were highly significant. An inhibitory effect on clonogenic capacity was also observed after cell treatment. Amongst all ILs; IL 4 (BMIMCl) exhibited potent activity against T98G brain cancer cells. Despite potent in-vitro activity, all ILs exhibited less cytotoxicity against the normal human HEK cells at all effective concentrations.

Protein folding/unfolding is a fascinating study in the presence of cosolvents, which protect/disrupt the native structure of protein, respectively. The structure and stability of proteins and their functional groups may be modulated by the addition of cosolvents. Ionic liquids (ILs) are finding a vast array of applications as novel cosolvents for a wide variety of biochemical processes that include protein folding. Here, the systematic and quantitative apparent transfer free energies (ΔG'(tr)) of protein model compounds from water to ILs through solubility measurements as a function of IL concentration at 25 °C have been exploited to quantify and interpret biomolecular interactions between model compounds of glycine peptides (GPs) with ammonium based ILs. The investigated aqueous systems consist of zwitterionic glycine peptides: glycine (Gly), diglycine (Gly(2)), triglycine (Gly(3)), tetraglycine (Gly(4)), and cyclic glycylglycine (c(GG)) in the presence of six ILs such as diethylammonium acetate (DEAA), diethylammonium hydrogen sulfate (DEAS), triethylammonium acetate (TEAA), triethylammonium hydrogen sulfate (TEAS), triethylammonium dihydrogen phosphate (TEAP), and trimethylammonium acetate (TMAA). We have observed positive values of ΔG'(tr) for GPs from water to ILs, indicating that interactions between ILs and GPs are unfavorable, which leads to stabilization of the structure of model protein compounds. Moreover, our experimental data ΔG'(tr) is used to obtain transfer free energies (Δg'(tr)) of the peptide backbone unit (or glycyl unit) (-CH(2)C═ONH-), which is the most numerous group in globular proteins, from water to IL solutions. To obtain the mechanism events of the ILs' role in enhancing the stability of the model compounds, we have further obtained m-values for GPs from solubility limits. These results explicitly elucidate that all alkyl ammonium ILs act as stabilizers for model compounds through the exclusion of ILs from model compounds of proteins and also reflect the effect of alkyl chain on the stability of protein model compounds.

In this communication, we present the ability of water and a protic ionic liquid, triethyl ammonium phosphate (TEAP) to act as refolding additives for the urea-induced chemical denaturated state of the two enzymes, α-chymotrypsin and succinylated Con A. We show that the enzymatic activity is regained and in certain circumstances enhanced.

Summary form only given. Non-thermal plasma is emerging as a novel tool for the treatment of living tissues for biological and medical purpose1. In this study we described the effect of plasma on human cancer cells in presence of ionic liquids (ILs)2. ILs having unique protective metabolic roles and they are acting as antioxidants, providing protects macromolecules, enhance protein folding and regulate cell volume. ILs is beneficial for the development of new bioactive materials, for example as anti-microbial or anti-septics or as anti-fouling reagents, or even as potential anti-cancer therapeutic agent3. Based on these interesting properties of ILs, non-thermal plasma in presence of ILs appears to provide a new outlook. A result of this study reveals that ILs in presence of plasma inhibits the cancer cells growth. ILs may also act as protecting agent for normal healthy cells from the damaging/toxic effect of plasma.

Mixing of ionic liquids (ILs) with molecular solvent can expand the range of structural properties and the scope of molecular interactions between the molecules of the solvents. Exploiting of these phenomena essentially require a basic fundamental understanding of mixing behavior of ILs with molecular solvents. In this context, a series of protic ILs possessing tetra-alkyl ammonium cation [R(4)N](+) with commonly used anion hydroxide [OH](-) were synthesized and characterized by temperature dependent thermophysical properties. The ILs [R(4)N](+)[OH](-) are varying only in the length of alkyl chain (R is methyl, ethyl, propyl, or butyl) of tetra-alkyl ammonium on the cationic part. The ILs used for the present study included tetramethyl ammonium hydroxide [(CH(3))(4)N](+)[OH](-) (TMAH), tetraethyl ammonium hydroxide [(C(2)H(5))(4)N](+)[OH](-) (TEAH), tetrapropyl ammonium hydroxide [(C(3)H(7))(4)N](+)[OH](-) (TPAH) and tetrabutyl ammonium hydroxide [(C(4)H(9))(4)N](+)[OH](-) (TBAH). The alkyl chain length effect has been analyzed by precise measurements such as densities (ρ), ultrasonic sound velocity (u), and viscosity (η) of these ILs with polar solvent, N-methyl-2-pyrrolidone (NMP), over the full composition range as a function of temperature. The excess molar volume (V(E)), the deviation in isentropic compressibility (Δκ(s)) and deviation in viscosity (Δη) were predicted using these properties as a function of the concentration of ILs. Redlich-Kister polynomial was used to correlate the results. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding between ILs and NMP molecules. Later, the hydrogen bonding features between ILs and NMP were also analyzed using a molecular modeling program with the help of HyperChem 7.

We report the synthesis of a series of ionic liquids (ILs) from various ions having different kosmotropicity including dihydrogen phosphate (H(2)PO(4)(-)), hydrogen sulfate (HSO(4)(-)) and acetate (CH(3)COO(-)) as anions and chaotropic cation such as trialkylammonium cation. To characterize the biomolecular interactions of ILs with protein, we have explored the stability of succinylated Con A (S Con A) in the presence of these aqueous ILs, which are varied combinations of kosmotropic anion with chaotropic cation such as triethylammonium dihydrogen phosphate [(CH(3)CH(2))(3)NH][H(2)PO(4)] (TEAP), trimethylammonium acetate [(CH(3))(3)NH][CH(3)COO] (TMAA), trimethylammonium dihydrogen phosphate [(CH(3))(3)NH][H(2)PO(4)] (TMAP) and trimethylammonium hydrogen sulfate [(CH(3))(3)NH][HSO(4)] (TMAS). Circular dichroism (CD) and fluorescence experiments have been used to characterize the stability of S Con A by ILs. Our data distinctly demonstrate that the long alkyl chain IL TEAP is a strong stabilizer for S Con A. Further, our experimental results reveal that TEAP is an effective refolding enhancer for S Con A from a thermally denatured protein structure.

We report the synthesis and characterization of a series of an ammonium ionic liquids (ILs) containing acetate, dihydrogen phosphate, and hydrogen sulfate anions with a common cation. To characterize the thermophysical properties of these newly synthesized ILs with the highly polar solvent N,N-dimethylformamide (DMF), precise measurements such as densities (ρ) and ultrasonic sound velocities (u) over the whole composition range have been performed at atmospheric pressure and over wide temperature ranges (25-50 °C). The excess molar volume (V(E)) and the deviation in isentropic compressibilities (Δκ(s)) were predicted using these temperature dependence properties as a function of the concentration of ILs. The Redlich-Kister polynomial was used to correlate the results. The ILs investigated in the present study included trimethylammonium acetate [(CH(3))(3)NH][CH(3)COO] (TMAA), trimethylammonium dihydrogen phosphate [(CH(3))(3)NH][H(2)PO(4)] (TMAP), and trimethylammonium hydrogen sulfate [(CH(3))(3)NH][HSO(4)] (TMAS). The intermolecular interactions and structural effects were analyzed on the basis of the measured and the derived properties. In addition, the hydrogen bonding between ILs and DMF has been demonstrated using semiempirical calculations with help of Hyperchem 7. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding between ILs and DMF molecules and their structural factors. The influence of the anion of the protic IL, namely, acetate (CH(3)COO), dihydrogen phosphate (H(2)PO(4)), and hydrogen sulfate (HSO(4)), on the thermophysical properties is also provided.

A new, highly efficient, inexpensive, recyclable, mild, convenient, and green protocol for chemoselective aza/thia-Michael addition reactions of amines/thiols to α,β-unsaturated compounds using triethylammonium acetate (TEAA) ionic liquid was developed. The catalyst can be recycled ten times and obviate the need for toxic and expensive catalysts.

The nature of solvent-biomolecule interactions is generally weak and non-specific. The addition of ionic liquids (ILs), which have emerged as a new class of solvents, strengthen the stability of some proteins whereas the same ILs weaken the stability of some other proteins. Although ILs are commonly used for the stabilization of biomolecules, the bimolecular interactions of their stabilization-destabilization is still an active subject of considerable interest and studies on this topic have been limited. To reveal the impact of ILs on the stability of proteins, a series of protic ILs possessing a tetra-alkyl ammonium cation [R4N](+) with a hydroxide [OH](-) anion were synthesized. In this study, we report the structural stability of heme proteins such as myoglobin (Mb) and hemoglobin (Hb) in a series of ammonium-based ILs such as tetramethyl ammonium hydroxide [(CH3)4N](+)[OH](-) (TMAH), tetraethyl ammonium hydroxide [(C2H5)4N](+)[OH](-) (TEAH), tetrapropyl ammonium hydroxide [(C3H7)4N](+)[OH](-) (TPAH) and tetrabutyl ammonium hydroxide [(C4H9)4N](+)[OH](-) (TBAH) by fluorescence and circular dichroism (CD) spectroscopic studies. Our experimental results reveal that less viscous ILs carrying smaller alkyl chain such as TMAH are strong destabilizers of the heme proteins as compared to the ILs carrying bulkier alkyl chains which are more viscous ILs, such as TBAH. Therefore, our results demonstrate that the addition of these ILs to the heme proteins decreases their thermal stability allowing the protein to be in an unfolded state at lower temperatures. Further, we describe the molecular-structural interaction of the heme proteins with the ILs (molecule like a ligand) by the PatchDocking method.

We present a biocompatible ionic liquid, triethyl ammonium acetate (TEAA), that attenuates the denaturation action of a non-ionic chaotrope, urea, on the industrially relevant proteolytic enzyme α-chymotrypsin.

The stability of proteins under co-solvent conditions is dependant on the nature of the co-solvent; the co-solvent can alter a protein's properties and structural effects through bimolecular interactions between its functional groups and co-solvent particles. Ionic liquids (ILs) represent a rather diverse class of co-solvents that are combinations of different ions, which are liquids at or close to room temperature. To quantify the bimolecular interactions of protein functional groups with biocompatible ILs, we report the systematic and quantitative apparent transfer free energies (ΔG'(tr)) of a homologous series of cyclic dipeptides (CDs) from water to aqueous solutions of ILs through solubility measurements, as a function of IL concentration at 25 °C under atmospheric pressure. The materials investigated in the present work included the CDs of cyclo(Gly-Gly), cyclo(Ala-Gly), cyclo(Ala-Ala), cyclo(Leu-Ala), and cyclo(Val-Val). The ILs used such as diethylammonium acetate ([Et(2)NH][CH(3)COO], DEAA), triethylammonium acetate ([Et(3)NH][CH(3)COO], TEAA), diethylammonium dihydogen phosphate ([Et(3)NH][H(2)PO(4)], DEAP), triethylammonium dihydogen phosphate ([Et(3)NH][H(2)PO(4)], TEAP), diethylammonium sulfate ([Et(3)NH][HSO(4)], DEAS) and triethylammonium sulfate ([Et(3)NH][HSO(4)], TEAS). We observed positive values of ΔG'(tr) for CDs from water to ILs, indicating that interactions between ILs and CDs are unfavourable, which leads to stabilization of the native structure of CDs. The experimental results were further used for estimating the transfer free energies (Δg'(tr)) of the peptide bond (-CONH-), the peptide backbone unit (-CH(2)C=ONH-), and various functional groups from water to IL solutions. Our results explicitly elucidate that a series of all ammonium ILs act as stabilizers for tested model compounds through the exclusion of ILs from CDs surface.

To understand the molecular interactions between N,N-dimethylformamide (DMF) with two families of ionic liquids (ILs), we have measured thermophysical properties such as densities (rho) and ultrasonic sound velocities (u) over the whole composition range at 25 degrees C under atmospheric pressure. The excess molar volume (V(E)) and the deviation in isentropic compressibilities (DeltaK(s)) were predicted using these properties as a function of the concentration of IL. These results are fitted to the Redlich-Kister polynomials. The materials investigated in the present study included two families of ILs such as ammonium salts and imidazolium salts. Diethylammonium acetate ([Et(2)NH][CH(3)COO], DEAA), triethylammonium actetate ([Et(3)NH][CH(3)COO], TEAA), triethylammonium dihydrogen phosphate ([Et(3)NH][H(2)PO(4)], TEAP), and triethylammonium sulfate ([Et(3)NH][HSO(4)], TEAS) are ammonium salts and 1-benzyl-3-methylimidazolium chloride ([Bmim][Cl]) belongs to the imidazolium family. The intermolecular interactions and structural effects were analyzed on the basis of the measured and the derived properties. A qualitative analysis of the results is discussed in terms of the ion-dipole, ion-pair interactions, and hydrogen bonding between ILs and DMF molecules and their structural factors.