Effect of DBU (1,8-Diazobicyclo[5.4.0]undec-7-ene) Based Protic Ionic Liquid on the Volumetric and Ultrasonic Properties of Ascorbic Acid in Aqueous Solution

Exploration of Diverse Interactions of l-Methionine in Aqueous Ionic Liquid Solutions: Insights from Experimental and Theoretical Studies

Here, we have investigated some physicochemical parameters to understand the molecular interactions by means of density (ρ) measurement, measurement of viscosity (η), refractive index(n _D) measurement, and conductance and surface tension measurements between two significant aqueous ionic liquid solutions: benzyl trimethyl ammonium chloride (BTMAC) and benzyl triethyl ammonium chloride (BTEAC) in an aqueous l-methionine (amino acid) solution. The apparent molar volume (Φ_v), coefficient of viscosity (B), and molar refraction (R _M) have been used to analyze the molecular interaction behavior associated in the solution at various concentrations and various temperatures. With the help of some important equations such as the Masson equation, the Jones-Doles equation, and the Lorentz-Lorenz equation, very significant parameters, namely, limiting apparent molar volumes (Φ_v ⁰ ), coefficient of viscosity (B), and limiting molar refraction (R _M ⁰), respectively, are obtained. These parameters along with specific conductance (κ) and surface tension (σ) are very much helpful to reveal the solute-solvent interactions by varying the concentration of solute molecules and temperature in the solution. Analyses of Δμ₁ ^0#, Δμ₂ ^0#, TΔS ₂ ^0#, ΔH ₂ ^0#, and thermodynamic data provide us valuable information about the interactions. We note that l-Met in 0.005 molality BTEAC ionic liquid at 308.15 K shows maximum solute-solvent interaction, while l-Met in 0.001 molality BTMAC aqueous solution of ionic liquid at 298.15 K shows the minimum one. Spectroscopic techniques such as Fourier transform infrared (FTIR), ¹H-NMR, and UV-vis also provide supportive information about the interactions between the ionic liquid and l-methionine in aqueous medium. Furthermore, adsorption energy, reduced density gradient (RDG), and molecular electrostatic potential (MESP) maps obtained by the application of density functional theory (DFT) have been used to determine the type of interactions, which are concordant with the experimental observations.

1,8-Diazabicyclo[5.4.0]-undec-7-ene based protic ionic liquids and their binary systems with molecular solvents catalyzed Michael addition reaction

Michael addition reaction of acetylacetone and cyclohexenone has been studied using 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) based protic ionic liquids and their binary systems with DBU, water and acetic acid as catalysts.

MechanoAPI-ILs: Pharmaceutical Ionic Liquids Obtained through Mechanochemical Synthesis

An alternative, efficient, and green synthetic strategy for the preparation of pharmaceutical ionic liquids using mechanochemistry (MechanoAPI-ILs) is reported. Six new API-ILs based on gabapentin and l-glutamic acid were successfully synthesized and characterized, demonstrating that mechanochemistry is a very promising synthetic strategy. Results compare both the new and the classical approach and clearly show the advantages of the new method. This new technique is faster, solvent free, reproducible, selective, and leads to higher yields.

Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach

The densities and viscosities of lactose monohydrate in aqueous ascorbic acid solutions with several molal concentrations m=(0.00-0.08)molkg(-1) of ascorbic acid were determined at T=(298.15-318.15)K and pressure p=101kPa. Using experimental data apparent molar volume (ϕV), standard partial molar volume (ϕV(0)), the slope (SV(∗)), apparent specific volumes (ϕVsp), standard isobaric partial molar expansibility (ϕE(0)) and its temperature dependence [Formula: see text] the viscosity B-coefficient and solvation number (Sn) were determined. Viscosity B-coefficients were further employed to obtain the free energies of activation of viscous flow per mole of the solvents (Δμ1(0≠)) and of the solute (Δμ2(0≠)). Effects of molality, solute structure and temperature and taste behavior were analyzed in terms of solute-solute and solute-solvent interactions; results revealed that the solutions are characterized predominantly by solute-solvent interactions and lactose monohydrate behaves as a long-range structure maker.

Elucidation of molecular interactions between a DBU based protic ionic liquid and organic solvents: thermophysical and computational studies

Energy profile of 1,8-diazabicyclo[5.4.0]undec-7-en-8-ium trifluoroacetate [DBUTFA].