Journal of Solution Chemistry最新文献

Simvastatin(Sim) is widely used for the prevention of cardiovascular disease and cancer treatment, but its solubility and bioavailability are poor. Therefore, the selection of β-cyclodextrin and ammonium acetate was explored to prepare ternary Sim inclusion complexes by freeze-drying method, the formation of ternary complex was confirmed by Electrospray ionization mass spectrometry (ESI-MS), Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), Scanning electron microscope (SEM), and X-ray diffraction (XRD) method. Compared to its solubility in pure water, the solubility of Sim in ternary complexes has increased by 46 times. The stable structure of complex was explored through 1H Nuclear magnetic resonance spectroscopy (NMR) and Density functional theory (DFT) calculation, Natural Bond Orbital (NBO) analysis revealed the interaction mechanism, where charge transfer and hydrogen bonding networks in the complex led to the locking of the Sim lactone ring within the narrower ring of β-CD, the NH₄Ac component leads to more hydrogen bond formation and enhances stability of drug. The proposed approach is a innovative systems for improving the solubility and stability of Simvastatin.

The growing demand for sustainable energy storage technologies drives the development of environment-friendly electrolytes with superior electrochemical performance. Conventional liquid electrolytes face challenges such as leakage and limited portability. Solid or quasi-solid electrolytes like ionogels and eutectogels offer promising alternatives; however, ionogels can be costly due to extensive use of ionic liquids (ILs), and eutectogels often suffer from restricted operating potential window. While eutectogels developed from natural deep eutectic solvents (NADESs) offer more benignity and a wider potential window, they possess low ionic conductivity. This study introduces hybrid eutectogel electrolytes by confining hydrophobic NADESs within a titania (TiO₂) matrix via a non-aqueous sol–gel process, mediated with 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF₄]). The goal is to address conductivity limitations observed in earlier NADES-based eutectogels by harnessing the synergistic properties of NADES, IL, and TiO₂. Electrochemical analyses using cyclic voltammetry and electrochemical impedance spectroscopy with reduced graphene oxide electrodes reveals a wide 4 V potential window, high ionic conductivity (14.53–16.28 mS·cm⁻¹), and decent specific capacitance (16.23–47.72 F·g⁻¹). Achieving specific energy up to 106 W·h·kg⁻¹, these eutectogels show strong potential as electrolytes for high-performance supercapacitors, paving the way for further material optimization.

Graphical Abstract

Thermophysical properties such as density (ρ), and viscosity (η) of pure components and binary mixtures of pyridine (PY) with 2-alcohols viz., 2-propanol (2-PPL), 2-butanol (2-BTL), and 2-pentanol (2-PTL) were measured over the entire range of composition of pyridine at varying temperatures T = (298.15, 303.15 and 308.15) K and at pressure 0.1 MPa. Using measured data, excess molar volume (({V}_text{m}^text{E})), and viscosity variation (∆η) were derived and correlated to the Redlich–Kister (R–K) polynomial equation. Further, the apparent molar volumes (({V}_{text m,varnothing ,1}) and ({V}_{text m,varnothing ,2})), partial molar volumes (({overline{V} }_{text m,1}) and ({overline{V} }_{text m,2})), and excess partial molar volumes (({overline{V} }_{text m,1}^{text E}) and ({overline{V} }_{text m,2}^{text E})) values were also derived. These characteristics are employed to explain the emergence of new intermolecular interactions (H-bonding, packing efficiency, and OH–π interaction) between dissimilar molecules. Over the whole range of pyridine composition, the ({V}_text{m}^text{E}) values showed a negative trend, while the ∆η values showed a positive trend. Furthermore, using thermodynamic results, discuss about how temperature affects molecular interactions between molecules.

In the present study, the density (ρ) and dynamic viscosity (η) of binary liquid mixtures such as glycerol (GLY) + isomers of butanol (1-butanol (1-BU), 2-butanol (2-BU), and tert-butanol (T-BU)) were experimentally measured as a function of glycerol mole fraction at T = (293.15 to 318.15) K and a pressure of 0.1 MPa. Using these experimental data, the deviation in viscosity (∆η), molar volume (({V}_{text m})), excess molar volume (({V}_text{m}^text{E})), apparent molar volumes (({V}_{text {m},varnothing ,1}) and ({V}_{text {m},varnothing ,2})), partial molar volumes (({overline{V} }_{text {m},1}) and ({overline{V} }_{text {m},2})), and excess partial molar volumes (({overline{V} }_{text {m},1}^{text E}) and ({overline{V} }_{text {m},2}^{text E})) values were calculated. The observed ({V}_text{m}^text{E}) and ∆η results were associated with the Redlich–Kister (R-K) model. Further, the ({V}_text{m}^text{E}) values were interpreted using the Prigogine–Flory–Patterson (PFP) model. The obtained ({V}_text{m}^text{E}) showed a negative deviation, and ∆η showed a positive deviation over the entire composition range of glycerol. The derived parameters in binary mixtures are affected by H-bonding. Moreover, the development of new H-bonding interactions between unlike molecules was further described using ¹H-NMR spectroscopy studies.

Endocrine-disrupting chemicals (EDCs) leach from consumer products, are persistent in the environment, and are implicated in adverse health outcomes. Commonly suspected to be xenoestrogens, binding and subsequent removal of EDCs such as bisphenol A (BPA), bisphenol S (BPS), parabens, nonylphenols, triclosan, and phthalates is important for both human and environmental health. Cyclodextrins (CDs) are known to bind estrogens and the EDCs bisphenol A and bisphenol S. We investigated the host–guest interactions of α-, β-, and γ- CDs with a range of suspected xenoestrogens via isothermal titration calorimetry (ITC) in aqueous solution and calculated binding stoichiometry, association constants, Gibbs free energy, enthalpy, and entropy for each EDC-CD pair. We found the strongest complexation between the suspected xenoestrogens and β-CD, with no significant interaction observed with any of the selected EDCs and α-CD and only two EDCs showing complexation with γ-CD. Those EDCs that exhibit higher binding may be more likely to adopt an estrogen-like conformation in aqueous solution, and we anticipate these data will provide information useful for future research in removing these harmful chemicals from the environment.

The solubility of dihydroxylammonium 5,5’-bistetrazole-1,1’-diolate (TKX-50) in three binary mixed solvents (ethanol + H₂O, DMSO + H₂O, and DMF + H₂O) was determined using a laser dynamic monitoring technique at various temperatures ranging from 293.15 to 333.15 K and at atmospheric pressure (P = 0.1 MPa). The results show that the solubility of TKX-50 in mixed solvents increases with temperature, decreases with increasing water content in DMSO + H₂O and DMF + H₂O, and increases with increasing water content in ethanol + H₂O. The experimental solubility data were used for correlation analysis using the Modified Apelblat equation, van’t Hoff equation, CNIBS/R-K equation, and Jouyban–Acree–Apelblat equation. All of these models yielded satisfactory results in binary solvents. Subsequently, the effects of hydrogen bonding, solvent polarity, and intermolecular interaction forces on the dissolution behavior of TKX-50 were analysed using Hansen solubility parameter (HSPs), Hirshfeld surface analysis (HS), and molecular electrostatic potentials (MEPs). In addition, the thermodynamic properties enthalpy, entropy, and Gibbs energy were calculated and discussed based on experimental data.

The main objective of this study is to understand the effect of a bio medically important organic salt on molecular interactions of ionic liquids. Volumetric and ultra-acoustic studies of two immidazolium based ionic liquids, 1-butyl-3 methyl imidazolium chloride and 1-ethyl-3-methyl imidazolium ethyl sulphate are carried out in presence of potassium dihydrogen citrate. Experimentally obtained and derived parameters are analysed in the light of ionic, hydrophilic, and hydrophobic interactions taking place between different ionic, polar, and nonpolar segments of the ILs and the citrate salt. The effect of the said salt on the interactions of the ILs with water are explored in terms of apparent molar volume ({(V}_{phi })), partial molar volume (({V}_{phi }^{0})), and partial molar expansibility ({(E}_{phi }^{0})), compressibility and apparent compressibility behaviour of solution at different concentrations ({{(K}_{s} text{and} K}_{phi ,s})) and at infinite dilution (({{K}_{s }^{0} text{and} K}_{phi ,s}^{0})). Transfer values are calculated to understand the solute–co-solute interactions and overlapping of hydration co-spheres. Hydration numbers are calculated to reinforce the compressibility data. Structural changes of water induced by the solute–co-solute and solute–solvent interactions are determined by the magnitude and sign of well-known Hepler’s constant.

Graphical Abstract

This work presents new data on the solubility of cadmium iodide in a mixture of N,N-dimethylacetamide (DMA) and N,N-dimethylformamide (DMF), as well as on the composition of crystalline compounds in equilibrium with the saturated solution. The solubility of the salt varies nonlinearly across the entire range of mixed solvent compositions. The solubility isotherm comprises four regions, each corresponding to the crystallization of individual solvates. The crystalline solvates exhibit similar structures and consist of the complex anion [Cd₂I₆]²⁻ and a complex cation, whose composition depends on the ratio of the components in the binary solvent. The cation includes either one of the amides or both in a 1:2 ratio, [Cd(DMA)₄(DMF)₂]²⁺ and [Cd(DMA)₂(DMF)₄]²⁺. Standard heats of dissolution in water were determined for both solvents and all solvates. From these data, the standard enthalpies of formation of the solvates were calculated. The enthalpies of formation of the solvates correlate with the molar ratio of amides in the complex cation and exhibit a direct dependence on the donor number of the amide.

Thermophysical properties such as density, and speed of sound of binary liquid systems of benzyl acetate (BZA) with 1-alkanols (1-propanol (PPL), 1-butanol (BTL), 1-pentanol (PTL), 1-hexanol (HXL), and 1-heptanol (HPL) at T = (298.15 to 308.15) K under atmospheric pressure, were reported complete composition of benzyl acetate. Using experimental data, thermodynamic properties like molar volume (({V}_{text{m}})), excess molar volume (({V}_{text{m}}^text{E})), apparent molar volumes (({V}_{text{m},varnothing ,1}) and ({V}_{text{m},varnothing ,2})), acoustic impedance (Z), isentropic compressibility (({k}_{text{s}})), intermolecular free length (L_f), excess isentropic compressibility (({k}_{text{s}}^{text{E}})), and excess intermolecular free length (({L}_{text{f}}^{text{E}})) were considered. Using these data, we may forecast the formation of new molecular interactions between dissimilar components, as well as explain how temperature influences those interactions. Further, the ({V}_{text{m}}^{text{E}}), and ∆κ_s variables were fitted using the Redlich–Kister (R–K) equation. Furthermore, the geometrical structure of the monomer and all conceivable H-bonded (molecular interaction) dimers is fully optimized using density functional theory with the Lee–Yang–Parr correlation function (B3LYP) and the 6-311++G(d, p) basis set. An extensive examination of the computational results is carried out to confirm the complex formation through H-bonding.

This is an experimental study of the complex formation between aqueous Ge(IV) and organic ligands of the α- and β-hydroxycarboxylate, α- and β-aminocarboxylate and (poly-)amino(poly-)carboxylate types in aqueous solution at 25.0 °C. α-substituted ligands (such as α-amino acid anions and ligands of the EDTA-family) were found to give rise to kinetically inert systems, which must be studied by a discontinuous potentiometric titration technique (i.e., for each titration point, an individual solution is prepared and left to equilibrate for extended periods of time). β-substituted ligands formed much weaker complexes and their reactions were labile. Speciation diagrams are presented and discussed for all the studied systems.