Partial molar volume and partial molar compressibility of four homologous α-amino acids in aqueous sodium fluoride solutions at different temperatures

Rajagopal, K.; Gladson, S. Edwin

doi:10.1016/j.jct.2011.01.004

Cited by 52 publications

(28 citation statements)

References 42 publications

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“…The relatively freer NH 3 + and COO − end Table 1 Standard partial molar volumes (V 2,φ 0 ) and experimental slopes S V for three glycyl dipeptides in aqueous [C n mim]Br (n=10, 14) solutions at different temperatures groups in glycylglycine will cause the maximum volume contraction followed by glycylvaline and least by glycylleucine in which the polar end groups are highly shielded by the bulky group -CHCH 3 CH 3 for electrostriction. Similar results were found for dipeptides in aqueous sodium carboxylate solutions [18][19][20][21] and amino acid in aqueous ionic liquid [5,22], methanoic acid [23], sodium fluoride [24], cetyltrimethylammonium bromide solutions [25], and so on. Furthermore, Fig.…”

Section: Resultssupporting

confidence: 78%

Apparent molar volume, conductivity, and fluorescence studies of ternary systems of dipeptides + ionic liquids ([Cnmim]Br, n = 10, 14) + water at different temperatures

et al. 2015

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Densities, conductivities, and fluorescence spectra of two imidazolium ionic liquids ([C n mim]Br, n=10, 14)-glycyl dipeptide-water mixtures were measured as a function of temperature. The density data have been utilized to calculate the apparent molar volumes, standard partial molar volumes (V 2,φ 0 ), standard partial molar volumes of transfer from water to aqueous ionic liquids solutions (Δ t V°), the hydration number (N H ), partial molar expansibility (E φ 0 ), and Hepler's constant of glycyl dipeptides. Through the electrical conductivity measurements, the c cmc values at different temperatures and a series of thermodynamic parameters (ΔG m o , ΔH m o , and ΔS m o ) of micellization of [C n mim]Br (n=10, 14) in aqueous glycyl dipeptides solutions are evaluated. The pyrene fluorescence spectra were used to study the change of micropolarity produced by the interaction of [C n mim]Br with glycyl dipeptide, and the aggregation behavior of [C n mim]Br (n=10, 14). The results shown above have been explained in terms of solutesolvent interactions and structural changes in the mixed solutions. The interaction between [C n mim]Br (n=10, 14) and glycyl dipeptide is affected by temperature and hydrocarbon chain length of the dipeptides.

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Section: Resultssupporting

confidence: 78%

Apparent molar volume, conductivity, and fluorescence studies of ternary systems of dipeptides + ionic liquids ([Cnmim]Br, n = 10, 14) + water at different temperatures

et al. 2015

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“…The total microscopic free energies calculated were compared with the experimental values taken from ref. 8 and the excess values were evaluated by applying equation [9][10][11][12][13][14][15].…”

Section: Discussionmentioning

confidence: 99%

The Microscopic Free Energies of Solvation for K+, Rb+ and Cs+ in Mixed Methanol (MeOH)-Dimethylformamide (DMFA) Solvents at 298.15 K

Gomaa¹

2012

IJTMP

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The microscopic charging ( ∆ G t charging), ion-dipole ( ∆ G t ion-dipole) and ion-induced dipole ( ∆ G t ioninduced dipole) free energies of transfer for some ions from methanol to mixed methanol (MeOH)-dimethylformamide (DMFA) solvents were calculated. These ions are potassium, rubidium and cesium. These theoretical free energies were compared with that of experimental values and the difference excess free energies of solvation were discussed. I t was observed that the excess free energies for all ions are positive and follow the following order:. Indicating more solvation behaviour by increasing the percentage of DMFA in the mixed solvents due to more attraction of these ions in the range rich in DMFA Keywords Microscopic free energy, potassium,robedium, cesium,excess free energy, organic solvents Calculations and ResultsThe electrostatic free energies of transfer ∆ G t (el) is known as the microscopic free energies of interaction [1]. The solvation free energies of ions is important in the applications of all fields,chemistry,physics and theoretical sciencesto obtain the corresponding energies of salts.Also chemical reactions can be theoreticaly expected to happen by knowing the free energy values for reactants and products. When we know the free energies of the ions we can easily obtain that for any simple, heavy element, lanthanide and actinide salts,which facilitate the explanation of different reactions.The salvation free energy of an ion has been formulated by number of authors cited by Covington[1] as a composite of neutral and electrostatic contribution.A neutral part may be considered to be equivalent to the salvation energy of uncharged molecules analogous to the ion in structure and size. The electrostatic contribution of the free energy is not exact evaluated before.In this work we did simple view to evaluate the electrostatic free energies and compare it with the available experimental values done by using the asymmetric Ph 4 AsPh 4 B (tetraphenylarsonium tetraphenylborate) assumption for evaluating single ion thermodynamics [Popovych...][2].

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“…Evaluation of individual ionic molar volumes [2], preferential salvation of drugs [3] partial molar volumes [4], ligands used for selective metal extraction 5 , ionic solvation 6 ,…”

Section: Introductionmentioning

confidence: 99%

The Association and Formation Constants for CuCl2 Stoichiometric Complexes with (E)-3-(2-Benzylidene Hydrazinyl)-3-oxo-N-(thiazol-2-yl)Propanamide in Absolute Ethanol Solution at 294.15 K

Ibrahim

Gomaa²,

Zaky³

et al. 2012

CHEMISTRY

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The association constants and Gibbs free energies for CuCl 2 with (E)-3-(2-benzylidene hydrazinyl)-3-oxo-N-(thiazol-2-yl)propanamide (H 2 BH) had been calculated by using the conductometric titration curves in absolute ethanol at 294.15 K. New equation was applied to determine the association constant for 1:2 asymmetric salts. Different stoichiometric complexes were obtained on drawing the relation between (/\ m ) and (M:L). The association free energies that were evaluated for CuCl 2 -ligand complexes were small and spontaneous indicating electrostatic attraction force.

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Partial molar volume and partial molar compressibility of four homologous α-amino acids in aqueous sodium fluoride solutions at different temperatures

Cited by 52 publications

References 42 publications

Apparent molar volume, conductivity, and fluorescence studies of ternary systems of dipeptides + ionic liquids ([Cnmim]Br, n = 10, 14) + water at different temperatures

Apparent molar volume, conductivity, and fluorescence studies of ternary systems of dipeptides + ionic liquids ([Cnmim]Br, n = 10, 14) + water at different temperatures

The Microscopic Free Energies of Solvation for K<SUP>+</SUP>, Rb<SUP>+</SUP> and Cs<SUP>+</SUP> in Mixed Methanol (MeOH)-Dimethylformamide (DMFA) Solvents at 298.15 K

The Association and Formation Constants for CuCl<SUB>2</SUB> Stoichiometric Complexes with (<i>E</i>)-3-(2-Benzylidene Hydrazinyl)-3-oxo-N-(thiazol-2-yl)Propanamide in Absolute Ethanol Solution at 294.15 K

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