scholarly journals Study of solute-solvent interactions of nicotinic acid and benzoic acid in methanol and its binary solvent systems

2008 ◽  
Vol 73 (12) ◽  
pp. 1235-1246 ◽  
Author(s):  
Nath Roy ◽  
Lovely Sarkar ◽  
Kumar Sarkar
Keyword(s):  
Benzoic Acid ◽  
Nicotinic Acid ◽  
Preferential Solvation ◽  
Mixed Solvents ◽  
Relative Viscosity ◽  
State Theory ◽  
Binary Solvent ◽  
Molar Volumes ◽  
Pure Methanol ◽  
B Coefficients

The apparent molar volumes, ?V, and viscosity B-coefficients, B, for nicotinic acid (NA) and benzoic acid (BA) in mixed solvents containing 10, 20, 30 mass % of n-amyl alcohol (n-AmOH) or isoamyl alcohol (i-AmOH) in methanol and in pure methanol (MeOH) were determined from the solution density and viscosity measurements at 298.15 K as function of concentrations of NA and BA. These results were, in conjunction with the results obtained in pure methanol, used to deduce the partial molar volumes of transfer, 0 ??V , and viscosity B-coefficients of transfer, ?B, for NA and BA from methanol to different mixed methanol solvents, in order to rationalize various interactions in the ternary solutions. An increase in the transfer properties of NA and BA with increasing mass % of n-AmOH and i-AmOH in methanol was observed and explained by the effect of structural changes and preferential solvation. Also, the free energies of viscous flow, ? 0? 1 ? and ? 0? ?2 , per mole of solvent and solute, respectively, were calculated and analyzed on the basis of the transition state theory of relative viscosity.

scholarly journals Volumetric, viscometric and refractive index behavior of amino acids in aqueous glycerol at different temperatures

2007 ◽  
Vol 72 (5) ◽  
pp. 495-512 ◽  
Author(s):  
A. Ali ◽  
S. Khan ◽  
F. Nabi
Keyword(s):  
Amino Acids ◽  
Mixed Solvents ◽  
Partial Molar Volumes ◽  
State Theory ◽  
Apparent Molar Volumes ◽  
Ternary Mixtures ◽  
Refractive Indices ◽  
Glycerol Solution ◽  
Molar Volumes ◽  
B Coefficients

Densities, ?, viscosities, ? and refractive indices, n D, of solutions of some amino acids (glycine, DL-alanine, DL-? -amino- n-butyric acid, L-valine and L-leucine) in the concentration range 0.02 to 0.10 m in 5 % (v/v) aqueous glycerol were determined at 298.15, 303.15, 308.15 and 313.15 K. These experimental data were used to calculate the apparent molar volumes, ? v, the infinite dilution apparent molar volumes, ? v 0, the partial molar volumes of transfer, ? v 0 (tr), of the amino acids from aqueous to aqueous glycerol solution, as well as the viscosity A and B coefficients of the Jones-Dole equation of the amino acids. The free energies of activation of viscous flow, ??1 0# and ?? 2 0# per mole of solvent and solute, respectively, were obtained by application of the transition-state theory to the B coefficient data and the corresponding activation enthalpy, ?H*, and entropy, ?S*, were also determined. The ? v 0, B coefficients and ?? 2 0# were found to vary linearly with increasing number of carbon atoms in the alkyl chain of the amino acids, and they were split into contributions from the zwitterionic end groups (NH3 +, COO-) and methylene (CH2) groups of the amino acids. The experimental values of the refractive indices, n D, were used to calculate the molar refractive indices, R D, of the amino acids + aqueous glycerol ternary mixtures. The results were interpreted in the light of the solute-solvent and solute-solute interactions in the mixed solvents.

scholarly journals Solvation in pure and mixed solvents: Some recent developments

2007 ◽  
Vol 79 (6) ◽  
pp. 1135-1151 ◽  
Author(s):  
Omar A. El Seoud
Keyword(s):  
Hydrogen Bonding ◽  
Hydrophobic Interactions ◽  
Preferential Solvation ◽  
Mixed Solvents ◽  
Effect Of Temperature ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Dispersion Interactions ◽  
Binary Solvent Mixtures ◽  
Recent Developments

The effect of solvents on the spectra, absorption, or emission of substances is called solvatochromism; it is due to solute/solvent nonspecific and specific interactions, including dipole/dipole, dipole-induced/dipole, dispersion interactions, and hydrogen bonding. Thermo-solvatochromism refers to the effect of temperature on solvatochromism. The molecular structure of certain substances, polarity probes, make them particularly sensitive to these interactions; their solutions in different solvents have distinct and vivid colors. The study of both phenomena sheds light on the relative importance of the solvation mechanisms. This account focuses on recent developments in solvation in pure and binary solvent mixtures. The former has been quantitatively analyzed in terms of a multiparameter equation, modified to include the lipophilicity of the solvent. Solvation in binary solvent mixtures is complex because of the phenomenon of "preferential solvation" of the probe by one component of the mixture. A recently introduced solvent exchange model allows calculation of the composition of the probe solvation shell, relative to that of bulk medium. This model is based on the presence of the organic solvent (S), water (W), and a 1:1 hydrogen-bonded species (S-W). Solvation by the latter is more efficient than by its precursor solvents, due to probe/solvent hydrogen-bonding and hydrophobic interactions. Dimethylsulfoxide (DMSO) is an exception, because the strong DMSO/W interactions probably deactivate the latter species toward solvation. The relevance of the results obtained to kinetics of reactions is briefly discussed by addressing temperature-induced desolvation of the species involved (reactants and activated complexes) and the complex dependence of kinetic data (observed rate constants and activation parameters) in binary solvent mixtures on medium composition.

scholarly journals Solubility modelling, solution thermodynamics and preferential solvation of hymecromone in binary solvent mixtures of N,N-dimethylformamide + methanol, ethanol or n-propanol

RSC Advances ◽  
2017 ◽  
Vol 7 (73) ◽  
pp. 46378-46387 ◽  
Author(s):  
Xinbao Li ◽  
Jiao Chen ◽  
Gaoquan Chen ◽  
Hongkun Zhao
Keyword(s):  
Preferential Solvation ◽  
Mixed Solvents ◽  
Solution Thermodynamics ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures

Solubilities of hymecromone in neat solvents of N,N-dimethylformamide (DMF), methanol, ethanol and n-propanol, and their binary mixed solvents of DMF + methanol, DMF + ethanol and DMF + n-propanol were determined.

scholarly journals Solution behavior of iron(III)-N,N'-ethylene-bis-(salicylideneiminato)-chloride in aqueous methanol at 298.15, 303.15 and 313.15K

2014 ◽  
Vol 79 (2) ◽  
pp. 225-239 ◽  
Author(s):  
Dhiraj Brahman ◽  
Biswajit Sinha
Keyword(s):  
Ambient Pressure ◽  
Activation Parameters ◽  
Partial Molar Volumes ◽  
State Theory ◽  
Aqueous Methanol ◽  
Molar Volumes ◽  
Ternary Solutions ◽  
Partial Molar Expansibilities ◽  
Solvent Molecules ◽  
B Coefficients

In this study partial molar volumes (?V0) and viscosity B-coefficients of iron(III)-N, N'-ethylene-bis(salicylideneiminato)-chloride, abbreviated as FeIII(salen)Cl, in different aqueous methanol solutions were determined from solution density and viscosity measurements at temperatures 298.15, 303.15, and 313.15 K under ambient pressure. Apparent molar volumes (?V) and densities (?) were used to calculate the apparent molar expansibilities (?E), the partial molar expansibilities (?E0) and the temperature dependence of the partial molar expansibilities (?E0) at constant pressure, (??E0/?T)P of FeIII(salen)Cl solutions to reveal the nature of different interactions in the ternary solutions. The transition state theory was applied to analyze the viscosity B-coefficients on the basis of the activation parameters of viscous flow. The overall results indicated strong solute-solvent interactions between FeIII(salen)Cl and the solvent molecules, preferentially with water molecules and that FeIII(salen)Cl acts as a net structure promoter in the ternary solutions. UV-VIS absorption spectra of the ternary solutions also stand in support of the results obtained.

scholarly journals Solution thermodynamics of aqueous nicotinic acid solutions in presence of tetrabutylammonium hydrogen sulphate

2013 ◽  
Vol 78 (8) ◽  
pp. 1225-1240 ◽  
Author(s):  
Abhijit Sarkar ◽  
Biswajit Sinha
Keyword(s):  
Aqueous Solutions ◽  
Nicotinic Acid ◽  
Ambient Pressure ◽  
Activation Parameters ◽  
Partial Molar Volumes ◽  
State Theory ◽  
Group Interactions ◽  
Molar Volumes ◽  
Solvent Interactions ◽  
Hydrogen Sulphate

In this study we investigated the effects of tetrabutylammonium hydrogen sulphate (Bu4NHSO4) on the solute-solute and solute-solvent interactions in the aqueous solutions of nicotinic acid in terms of apparent molar volumes (?V), standard partial molar volumes (?V0) and viscosity B-coefficients at 298.15, 308.15, and 318.15 K under ambient pressure. These interactions are further discussed in terms of ion-dipolar, hydrophobic- hydrophobic, hydrophilic-hydrophobic group interactions. The activation parameters of viscous flow for Bu4NHSO4 in the aqueous solutions of nicotinic acid were discussed in terms of transition state theory. The overall results indicated that ion-hydrophilic and hydrophilic-hydrophilic group interactions are predominant in the aqueous solutions of nicotinic acid and Bu4NHSO4 has a dehydration effect on the hydrated nicotinic acid.

Preferential solvation of Co2+ and Ni2+ ions in mixed solvents: n.m.r. methods

1968 ◽  
Vol 46 (20) ◽  
pp. 3183-3187 ◽  
Author(s):  
L. S. Frankel ◽  
T. R. Stengle ◽  
C. H. Langford
Keyword(s):  
Preferential Solvation ◽  
Mixed Solvents ◽  
Alternative Methods ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Significant Information ◽  
Coordination Sites ◽  
Coordination Spheres ◽  
Solvent Molecules ◽  
Solvent Proton

A method for the study of preferential solvation in the outer coordination spheres from paramagnetic broadening of solvent proton n.m.r. signals was proposed by Frankel, Stengle, and Langford. It is now extended to determinations of the relative concentrations of water and dioxane, dimethylformamide, or dimethylsulfoxide in the inner coordination spheres of Co2+ and Ni2+ ions in the binary solvent mixtures. The assumptions of the analysis are cross-checked by a new method based on the contact shifts experienced by protons on solvent molecules in the coordination spheres of paramagnetic ions. The second method depends upon assumptions independent of the first. Three cases are presented as tests of these n.m.r. approaches. It is clear that highly precise solvation sphere populations will be difficult to obtain but that useful and significant information can be obtained in situations to which alternative methods are almost totally inapplicable.The results indicate that dimethylsulfoxide and dimethylformamide are good competitors for coordination sites but that dioxane is excluded by water.

scholarly journals Solution thermodynamics of sodium pyruvate in aqueous glycine solutions at T 298.15-313.15 K

2016 ◽  
Vol 81 (11) ◽  
pp. 1283-1294 ◽  
Author(s):  
Bijan Pandit ◽  
Abhijit Sarkar ◽  
Biswajit Sinha
Keyword(s):  
Ambient Pressure ◽  
Activation Parameters ◽  
Partial Molar Volumes ◽  
State Theory ◽  
Solution Thermodynamics ◽  
Sodium Pyruvate ◽  
Group Interactions ◽  
Molar Volumes ◽  
Solvent Interactions ◽  
B Coefficients

In this study we investigated the effects of sodium pyruvate on the solution thermodynamics of glycine in terms of the solute-solute and solute-solvent interactions in aqueous solutions. Measured density and viscosity were used to derive apparent molar volumes (?V), standard partial molar volumes (?V0) and viscosity B-coefficients at 298.15, 303.15 K, 308.15, and 318.15 K under ambient pressure. The interactions are further discussed in terms of ion-dipolar, hydrophobic- hydrophobic, hydrophilic-hydrophobic group interactions. The activation parameters of viscous flow were also discussed in terms of transition state theory. The overall results indicated that ion-hydrophilic and hydrophilic-hydrophilic group interactions are predominant in the ternary solutions.

Preferential Solvation of Ions in Mixed Solvents

1986 ◽  
Vol 150 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Dip Singh Gill ◽  
Suvarcha Chauhan ◽  
Mohinder Singh Chauhan
Keyword(s):  
Preferential Solvation ◽  
Mixed Solvents ◽  
Solvation Of Ions
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