Partial Molar Volumes Of Transfer Research Articles

Solute-solvent interactions of amino acid l-phenylalanine in aqueous 1-butyl-2,3-dimethylimidazolium bromide ionic liquid solutions

Densities of l-phenylalanine in water and in aqueous1-butyl-2,3-dimethylimidazolium bromide solutions, at T=(283.15, 288.15, 293.15, 298.15 and 303.15)K and atmospheric pressure have been measured. The apparent molar volumes, VФ, standard partial molar volumes, VФ0, limiting apparent molar expansibilities, EФ0, and standard partial molar volumes of transfer, ΔVФ0, have been calculated. The values of ΔVФ0 are negative. These volumetric parameters are interpreted in terms of various mixing effects between l-phenylalanine and [BMMIm]Br in aqueous solution. The 1H NMR measurements of binary mixtures of l-phenylalanine and [BMMIm]Br in D2O solutions have been carried out to understand the possible interactions. The results show that the interactions between the hydrophobic-hydrophobic groups of [BMMIm]Br and l-phenylalanine may be dominant in the studied system. Furthermore, the density functional theory calculations provide stabilization energies and suggest possible interaction ways that support the volumetric and NMR measurements.

Effect of anionic micellar medium on thermo-acoustical parameters of aspartic acid and serine solutions

Density and sound velocity data for aspartic acid and serine in water and in aqueous solution of anionic surfactant; Sodium dodecyl sulphate (SDS) were measured over a temperature range (303.15K–313.15K). Various volumetric and acoustical parameters including apparent molar volume (Φv), partial molar volume (Φvo), partial molar transfer volume, apparent molar isentropic compressibility (Φk), partial molar isentropic compressibility (Φok) and intermolecular free length (Lf) etc. for amino acid solutions in water and in aqueous surfactant (SDS) solutions were calculated from the measured data of density and sound velocity. The abovementioned calculated parameters have been used to explore the amino acid-surfactant interactions. Values of apparent molar volume are positive at all temperatures and are increasing with increasing temperature and amino acids concentrations. Similarly, intermolecular free length decreases with increasing amino acids concentrations both in water and aqueous surfactants solutions, which indicate strong intermolecular interactions in amino acids solutions. From results it is also obvious that due to the presence of resonance stabilization, aspartic acid interacts more strongly in both aqueous and SDS environment than serine.

Hydration and Solvation Effect of Glycine and Glycylglycine Molecules with β-Cyclodextrin in Aqueous Media. A Thermodynamic Characteristic of Interaction

Abstract The densities, ρ and viscosities, η have been measured for DL- glycine (Gly) and glycylglycine (Gly-Gly) in aqueous β cyclodextrin, (β-CD) at temperature 298.15, 303.15, 308.15, 313.15 and 318.15 K. Interaction between macrocyclic β-CD and amino acids was studied by two independent technique: density and viscosity. The two different intensive properties are used to obtain various thermodynamic characteristics of the material behavior. Using the measured density data the apparent molar volumes, Vϕ , partial molar volume at infinite dilution, V ϕ ο , $V_\phi ^o,$ experimental slope, SV , isobaric expansibility, ϕ E 0 , $\phi _E^0,$ and the partial molar volume of transfer at infinite dilution, Δ V ϕ ( t r ) ο $\Delta V_{\phi (tr)}^o$ have been obtained. Moreover, the Falkenhagen’s theoretical coefficient, A, Jones-Dole coefficient, B, free energies of activation of viscous flow per mole of solvent, Δ μ 1 ο # $\Delta \mu _1^{o\# }$ and per mole of solute, Δ μ 2 ο # , $\Delta \mu _2^{o\# },$ enthalpy, ΔHo # and entropy, ΔSo # of activation of viscous flow have been evaluated by using viscosity data. The negative value of transfer volume for Gly and Gly-Gly in aqueous β-CD suggests that the hydrophobic-hydrophilic and hydrophobic-hydrophobic interactions are predominating over ionic-hydrophilic and hydrophilic-hydrophilic interactions. The results indicate the formation of a stable complexation between the β-CD cavity and structural hydration effect of amino acids on the thermodynamic of their interactions in solutions.

Volumetric Behavior of Sodium Saccharin in Water and (0.1, 0.3, and 0.5) m Fructose at (298.15, 303.15, 308.15, and 313.15) K

In order to get the information regarding the sweetener-water and sweetener-sweetener interactions, densities of sodium saccharin in water and (0.1, 0.3, and 0.5) m fructose have been measured at (298.15, 303.15, 308.15, and 313.15) K by the use of bicapillary pycnometer. From density values, partial molar volumes, expansion coefficient, Hepler’s constant, apparent specific volumes, partial molar volumes of transfer, doublet and triplet interaction coefficients have been calculated. From density study, it has been concluded that strong water-sodium saccharin interactions exist. Sodium saccharin is water structure maker. Strong interactions exist between sodium saccharin and fructose. In presence of fructose, the interactions exist between hydrophilic group (–OH, C=O, and –O–) of fructose and sodium ion of sodium saccharin in aqueous solutions of sodium saccharin. All investigated solutions exhibit sweet taste. DOI: http://dx.doi.org/10.17807/orbital.v9i1.921

Mode of action of betaine on some amino acids and globular proteins: Thermodynamic considerations

The interactions of the amino acids glycine, l-alanine, dl-α-amino-n-butyric acid, l-valine, and l-leucine have been studied based on values of apparent molar volume (V2,m,ϕ) and apparent molar compressibility (Ks,2,m,ϕ) in 1mol·kg−1 and 2mol·kg−1 aqueous betaine solutions at T=298.15K. These thermodynamic quantities have been calculated from density and sound velocity measurements. Isothermal titration calorimetry has been employed to determine the values of enthalpies of interaction of aqueous solutions of these amino acids with betaine. These data have been further used to calculate values of infinite dilution standard partial molar volumes (V2,mo), standard partial molar isentropic compressibilities (Ks,2,mo) and limiting enthalpies of dilution (ΔdilHmo) of these amino acids in aqueous betaine solutions. The standard partial molar volumes of transfer (ΔtrV2,mo), isentropic compressibilities of transfer (ΔtrKs,2,mo) and enthalpies of dilution of transfer Δtr(ΔdilHom) of amino acids from water to aqueous betaine solutions have been calculated from the measured data in order to understand possible intermolecular interactions such as ion-ion, ion-polar, hydrophilic-hydrophobic and hydrophobic-hydrophobic group interactions. The contributions of the end groups {(NH3+, COO−), CH2 groups and the other alkyl chains of the amino acids to V2,mo} have also been determined. The interactions of betaine with the globular proteins α-lactalbumin and bovine serum albumin have also been studied. Such studies are important in obtaining information on the action of osmolytes on proteins and their constituents and establishing possible correlations.

Volumetric and viscometric properties of amino acids in aqueous maltitol solutions at T = (293.15–323.15) K

The densities and viscosities of the ternary mixtures of glycine, l-alanine, l-valine, l-threonine and l-arginine in aqueous maltitol solutions were measured at T=(293.15–323.15)K under the atmospheric pressure. The apparent molar volume (Vφ), the limiting partial molar volume (Vφ0) and the limiting partial molar volume of transfer (ΔtrVφ0) were obtained in terms of the measured density, then the viscosity B-coefficient was further calculated by the least-square method. Meanwhile, the partial molar isobaric expansion (E20), the isobaric thermal expansion coefficient (α2), the solvation number (nS), the free energies of activation per mole of solvent (Δμ10≠) and per mole of solute (Δμ20≠) were also calculated. The volumetric and viscometric properties were analyzed and discussed according to the interactions between amino acids and maltitol molecules based on the co-sphere overlap model and the transition state theory.

Solvation behavior of glycine and glycyl dipeptide in aqueous 1-butyl-3-methylimidazolium bromide ionic liquid solutions at different temperatures

Densities and speeds of sound of glycine and glycyl dipeptide (glycylglycine) in aqueous 1-butyl-3 methylimidazolium bromide, [C4mim][Br] solutions have been measured at T=(288.15, 298.15 and 308.15) K. From the experimental data of density and speed of sound, the apparent molar volumes (Vϕ), apparent molar volumes at infinite dilution (Vϕ0), apparent molar isentropic compression (Kϕ,s) and apparent molar isentropic compression at infinite dilution (Kϕ,S0) have also been determined. Further, the partial molar volumes of transfer (ΔtrVϕ0) and partial molar isentropic compression of transfer (ΔtrKϕ,S0) of glycine and glycyl dipeptide from water to aqueous [C4mim][Br] solutions were calculated to enlighten the interactions such as solute–solute, solute–solvent and solvent–solvent present in these solutions. The apparent molar expansivity (Eϕ0), Hepler's constant values ∂Eϕ0∂TP,thermal expansion coefficient (α) and hydration number (nH) have been evaluated to assist the interpretations earned from the volumetric and acoustic analysis. The Hepler's constant values were found negative for glycine and glycyl dipeptide at all concentrations of ionic liquid except at lower concentration with glycyl dipeptide. The negative sign indicates the co-solutes act a structure breaker.

Study of the Influence of Alkyl Chain Cation Solvent Interactions on the Slope of ϕv v/s √C Curves in 1, 3-Butanediol-DMF Solvent Mixtures by Apparent Molar Volume Measurements

The concept of Frank's hypothesis (that is the effect of large tetra alkyl ammonium ions on the solvent structure, especially water, in the ion-ion and ion-solvent interactions) was found to be not applicable when water was replaced by one of the organic solvents e.g. Dimethyl formamide (DMF), in the solvent mixture, that is, if the study involves ion-ion and ion- solvent interactions in 1,5-pentane diol - DMF solvent mixture containing large cations of tetraalkyl ammonium iodides. The densities of binary solvent mixtures and salt solutions have been measured at 298.15 K by magnetic float densitometer. The apparent molar volumes at infinite dilution, ФV 0 , determined by ФV -values in the solvent mixtures, have been utilized to estimate the partial molar volumes of transfer, ΔФV 0 (tr), for various tetraalkyl ammonium iodide salts from DMF to 1,5-Pentane diol.

The study of solute–solvent interactions in the ternary {Amino acid (Glycine or l-serine) + ionic liquid (1-butyl-3-methylimidazolium tetra fluoroborate [Bmim][BF4]) + H2O} system at different temperatures and ambient pressure: Volumetric study

Abstract The solute–solvent interactions in the studied aqueous ternary systems containing some amino acids (Glycine or l -serine) and ionic liquid (1-butyl-3-methylimidazolium tetra fluoroborate [Bmim][BF4]) are studied by using the volumetric properties data. These properties contains: apparent molar volumes, standard partial molar volumes, limiting partial molar volumes of transfer, apparent molar expansibility and hydration number. Vφ values were increased when rising concentration of amino acids and also temperature while decreased by increasing concentration of ionic liquid. Apparent molar volumes of transfer, ΔVφ0, for studied amino acids from water to aqueous solutions of ionic liquid (IL) are calculated. The limiting partial molar volumes of transfer ΔtVφ0 values were negative. Results confirmed the dominance of hydrophobic-hydrophobic interactions in both ternary solutions.

COMPORTAMIENTO VOLUMÉTRICO DE LA DL-VALINA EN SOLUCIONES ACUOSAS DE NITRATO DE SODIO A DIFERENTES TEMPERATURAS

Densities of DL-valine (2-amino-3-methylbutanoic acid) in aqueous solutions of sodium nitrate were determined at temperatures ranging from 283.15 to 318.15 K using an Anton Paar DMA 5000 vibrating tube densitometer. The apparent molar volume, infinite dilution apparent molar volume, second derivative of the infinite dilution partial molar volume with respect to temperature, partial molar volume of transfer at infinite dilution and the number of hydration were calculated. The results obtained were discussed in terms of the dominant interactions in solution, it was found that the DL-valine has a disruptor effect in the structure of the solvent and that at infinite dilution solute-solvent interactions are dominant between isopropyl group the amino acid and sodium and nitrate ions.

Densities and Viscosities of Amino Acid + Xylitol + Water Solutions at 293.15 ≤ T/K ≤ 323.15

Densities (ρ) and viscosities (η) of aqueous xylitol solutions with glycine, l-alanine, l-valine, l-threonine, or l-arginine were measured at T = (293.15 to 323.15) K under atmospheric pressure. The density values were utilized to further calculate the apparent molar volume (Vφ), the limiting partial molar volumes of amino acids (Vφ0), the limiting partial molar volumes of transfer (ΔtrVφ0) and the interaction coefficients Vab, Vabb, Vabbb. The viscosity data were used to obtain viscosity B-coefficient, the free energies of activation per mole of solvent (Δμ10≠) and solute (Δμ20≠). The limiting partial molar volumes of transfer and the free energies of activation per mole of both solvent (Δμ10≠) and solute (Δμ20≠) were analyzed based on the cosphere overlap model and transition state theory, respectively. The hydration number of amino acid was determined using the obtained limiting partial molar volume and viscosity B-coefficient.

Study of interactions of d(+)-glucose and d(−)-fructose with trilithium citrate in aqueous medium through volumetric and ultrasonic properties over the temperature range T = (288.15–318.15) K

The interactions of salt trilithium citrate (TLC) with saccharides d(+)-glucose and d(−)-fructose, have been investigated in aqueous medium from density (ρ) and speed of sound (c) measurements at T=(288.15–318.15) K and experimental pressure p=0.1MPa. The apparent molar volume (Vϕ), the partial molar volume (Vϕo) and standard partial molar volumes of transfer (ΔVϕo) for both saccharides, from water to aqueous trilithium citrate (TLC) have been calculated from density data. The limiting apparent molar expansibilities have also been calculated. The apparent molar isentropic compression (Kϕ,s), partial molar isentropic compression (Kϕ,so) and partial molar isentropic compression of transfer (ΔKϕ,so) have been calculated from speed of sound results. The pair and triplet interaction coefficients have been calculated from partial molar volumes of transfer and partial molar isentropic compression of transfer. A detailed insight into the physicochemical interactions e.g. ion–hydrophilic, hydrophilic–hydrophilic and hydrophilic–hydrophobic interactions in the saccharide-salt system along with the structure-making/structure-breaking tendency of the saccharides, have been retrieved through the perusal of these calculated parameters.

Interactions of 1-butyl-2,3-dimethylimidazolium bromide ionic liquid with glycine, l-alanine and l-valine: A volumetric and NMR spectroscopic study

The densities of glycine, l-alanine and l-valine in aqueous and aqueous solutions of 1-butyl-2,3-dimethylimidazolium bromide [BMMIm]Br have been determined at (283.15, 288.15, 293.15, 298.15 and 303.15) K and atmospheric pressure. The apparent molar volumes, standard partial molar volumes, standard partial molar volume of transfer and hydration numbers have been calculated. The values of standard partial molar volume of transfer for three amino acids are negative at all temperatures studied. The values of standard partial molar volume of transfer become more negative with the increase of hydrophobicity of the amino acid side-chains. These volumetric parameters are interpreted in terms of various mixing effects between amino acids and [BMMIm]Br in aqueous solutions. Furthermore, the 1H NMR measurements of binary mixtures of amino acids and [BMMIm]Br dissolved in D2O have been carried out. The influence in electron density around the protons of [BMMIm]Br followed the order: l-valine>l-alanine>glycine. The results were interpreted on possible molecular interactions between the intrinsic hydrophilicity/hydrophobicity of amino acid side-chains and [BMMIm]Br.

Densities and Speeds of Sound of Antibiotic Drug Chloramphenicol with l-Leucine and Glycyl-l-leucine in Aqueous Medium at T = (288.15–318.15) K: A Volumetric, Ultrasonic, and UV Absorption Study

From the density (ρ) and speed of sound (c) measurements, the interactions of drug chloramphenicol with l-leucine and the dipeptide glycyl-l-leucine, have been examined in aqueous medium at T = (288.15–318.15) K and experimental pressure p = 0.1 MPa. For l-leucine and the dipeptide, the apparent molar volume (Vϕ), the apparent partial molar volume (Vϕo), and the apparent partial molar volumes of transfer (ΔVϕo), from water to aqueous chloramphenicol have been calculated from density data. We have also calculated the limiting apparent molar expansibilities. From the speed of sound data, apparent molar isentropic compression (Kϕ,s), apparent partial molar isentropic compression (Kϕ,so), and apparent partial molar isentropic compression of transfer (ΔKϕ,so) have been calculated. The pair and triplet interaction coefficients are determined from apparent partial molar volumes of transfer and apparent partial molar isentropic compression of transfer. For the present mixtures, the absorption spectra have also be...

Solvation behaviour of some amino acids in aqueous solutions of an antibiotic drug streptomycin sulfate at different temperatures: Volumetric, acoustic and viscometric approach

The volumetric, acoustic and viscometric approach has been used for investigating the interactions of l-serine, l-threonine and l-leucine in aqueous solutions of an antimycobacterial drug, namely, streptomycin sulfate, over a temperature range of (305.15, 310.15 and 315.15) K at atmospheric pressure. The apparent molar volume, Vϕ, limiting apparent molar volume, V0ϕ, the slope, Sv, partial molar volume of transfer, V0ϕ, tr, limiting apparent molar expansivity, E0ϕ, and Hepler's constant, (∂2V0ϕ/∂T2)P, have been calculated from density data. The apparent molar isentropic compression, Kϕ,s, limiting apparent molar isentropic compression, K0ϕ,s, its slope, Sk, and partial molar isentropic compression of transfer, K0ϕ,s,tr, have been calculated from speed of sound data. The compression data is also used for calculating the number of water molecules hydrated, nH, to the amino acids. The viscosity data has been used to determine relative viscosity ηr, viscosity B-coefficients, temperature derivative of B-coefficients, dB/dT and viscosity B-coefficients of transfer, Btr. Solvation behaviour, of amino acids has also been computed. The calculated parameters have been discussed in terms of various solute–solute and solute–solvent interactions prevailing in these solutions. Further, a detailed insight into the physicochemical interactions, e.g., ion-hydrophilic and hydrophilic–hydrophilic interactions in the amino acids in conjunction with the drug along with the structure-making/structure-breaking tendency has been retrieved through the perusal of these calculated parameters.

Interactions of L-Aspartic Acid with Aqueous Solution of 1,2-Propanediol at Different Temperatures: A Volumetric, Compressibility and Viscometric Approach.

The volumetric, acoustic and viscometric methods are used for investigating the interactions of L-aspartic acid (Asp) in aqueous solution of 1,2-propanediol (PD) over a temperature of (298.15, 303.15 and 308.15) K at atmospheric pressure. Using the experimental results, the apparent molar volume, Vφ, limiting apparent molar volume, V0φ, the slope, Sv, and partial molar volume of transfer, V0φ,tr, have been calculated from density data. The apparent molar isentropic compressibility, K φ,s, limiting apparent molar isentropic compressibility, K0φ,s, its slope, Sk, and partial molar compressibility of transfer, K0φ,s, tr, have been calculated from speed of sound data. These values are also used for calculating the number of water molecules hydrated, nH, to the Asp. The viscosity data has also been used to determine relative viscosity ηr, viscosity B-coefficients, temperature derivative of B-coefficients, dB/dT and viscosity B-coefficients of transfer, Btr. The calculated parameters have been discussed in terms of various solute-solute and solute-solvent interactions prevailing in these solutions. Further, a detailed insight into the physicochemical interactions between Asp and aqueous PD, e.g., ion-hydrophilic and hydrophilic-hydrophilic interactions along with the structure-making tendency have been retrieved through the perusal of these calculated parameters.

Conductometric and volumetric study of copper sulphate in aqueous ethanol solutions at different temperatures

An Anton Par Model 55 densimeter was used to measure the densities of copper sulphate solutions in H2O and EtOH–H2O at 298.15K, 303.15K, 308.15K, and 313.15K. The acquired information was used to ascertain the apparent molar volumes, limiting partial molar volumes, and transfer partial molar volumes of copper sulphate. These computed parameters were utilized to decipher the solute–solute and solute–solvent interactions of copper sulphate in an aqueous ethanol solution. The ion solvation behavior of copper sulphate in water and aqueous ethanol over the range of 298.15–313.15K was studied using the electrical conductivity principle. The Kraus–Bray and Shedlovsky models of conductivity were used to analyze the obtained conductance data. From the obtained data, the limiting molar conductance λ°m, association constant KA, energy of activation of the rating process (Ea), and related thermodynamic parameters were determined. The Walden product (λ°mη0) was determined. The standard thermodynamic parameters of association (ΔG°A, ΔH°A) were calculated and discussed. Increased ion–solvent and solvent–solvent interactions are indicated by limiting molar conductance values with an increasing amount of ethanol. The negative ΔG°A values indicate that the association processes in all of the studied systems are spontaneous processes. The negative estimation of (ΔH°A) demonstrates that the association processes is exothermic in nature.

Volumetric behavior of glycine in aqueous succinic acid and sodium succinate buffer at different temperatures

Apparent molar volume (∅V) of glycine in aqueous succinic acid and in aqueous sodium succinate buffer solutions have been determined from precisely measured density data at different temperatures ranging from 288.15 to 328.15K. The ∅V values of glycine in aqueous succinic acid solutions increase with increase in molality of glycine and temperature whereas ∅V values of glycine in sodium succinate buffer shows different behavior as a function of molality and temperature at pH=1.00, 7.40 and 14.00. Partial molar volume at infinite dilution (∅Vo) and partial molar volume of transfer (∆Vtr) has been determined from∅V. Both positive and negative ∆Vtr values have been observed for glycine in the presence of sodium succinate buffer solutions, whereas only negative, ∆Vtr values have been observed in the presence of aqueous succinic acid solutions. Partial molar expansibilities∂∅Vo∂TPdetermined from ∅Vo data, are higher in the presence of buffer solutions as compared to that of aqueous succinic acid solutions. Hydration numbers (nH) for glycine in aqueous succinic acid solutions are higher than in aqueous sodium succinate buffer solutions at pH7.40, which suggest a dehydration effect in later case.

Thermodynamics of (solute + solute) and (solute + solvent) interactions of homologous series of amino acids with thiamine hydrochloride in aqueous medium at T = (305.15, 310.15, 315.15) K: A volumetric and acoustic approach

Apparent molar volumes (Vϕ) and apparent molar isentropic compression (Kϕ,s) of glycine, l-alanine, l-valine and l-leucine in (0.05, 0.10, 0.15, 0.20)mol·kg−1 aqueous solution of thiamine hydrochloride (thiamine-HCl) have been determined at T=(305.15, 310.15 and 315.15)K and experimental pressure p=0.1MPa, from the density and speed of sound measurements. The partial molar volume Vϕo, standard partial molar volumes of transfer ΔVϕo for amino acids from water to aqueous thiamine-HCl, partial molar isentropic compression Kϕ,s and partial molar isentropic compression of transfer ΔKϕ,so have been calculated from the corresponding data. Group contributions of amino acids to partial molar volume are also determined. The pair and triplet interaction coefficients are obtained from partial molar volumes of transfer and partial molar isentropic compression of transfer. The partial molar expansibility (∂Vϕo/∂T)p, second order derivative (∂2Vϕo/∂T2)p have also been calculated. The parameters obtained have been used to explain the results in terms of (solute-solute)/(ion-ion), (solute-solvent) interactions, structure making and structure breaking behaviour of amino acids in aqueous thiamine-HCl solutions.

Densities and Speeds of Sound of d(+)-Glucose, d(−)-Fructose, d(+)-Xylose and d(−)-Ribose in Aqueous Tripotassium Citrate Solutions at Different Temperatures

Apparent molar volumes (Vϕ) and apparent molar isentropic compressions (Kϕ,S) for some monosaccharides {d(+)-glucose, d(−)-fructose, d(+)-xylose and d(−)-ribose} in (0.0, 0.2, 0.4, 0.6) mol·kg–1 aqueous solutions of tripotassium citrate (TPC) have been determined from density and speeds of sound measurements along four isotherms at temperatures between (288.15 and 318.15) K at experimental pressure p = 0.1 MPa using an automated vibrating tube densimeter (Anton Paar DSA 5000 M). The experimental values are used to determine partial molar volume (Vϕ0), partial molar isentropic compression (Kϕ,S0) at infinite dilution and their corresponding partial molar volumes of transfer (ΔVϕ0), and partial molar isentropic compression of transfer (ΔKϕ,S0). The expansibility parameter (∂Vϕ0/∂T)P and its derivative (∂2Vϕ0/∂T2)P along with pair (VAB, KAB) and triplet (VABB, KABB) interaction coefficient for density and speed of sound data have been determined. The interpretation of the data has been made in terms of solut...