Solvent effect in dissociation of substituted benzenesulphonamides in dimethylformamide, dimethyl sulphoxide, and acetonitrile

1984 ◽  
Vol 49 (11) ◽  
pp. 2593-2601 ◽  
Author(s):  
Miroslav Ludwig ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Factor Analysis ◽  
Solvent Effect ◽  
General Formula ◽  
Potentiometric Titration ◽  
Dissociation Constants ◽  
Dimethyl Sulphoxide ◽  
Short Cycle ◽  
Testing Method

Dissociation constants of fifteen substituted arenesulphonamides of general formula XC6H4.SO2NH2 (or X2C6H3SO2NH2) have been measured by potentiometric titration in dimethylformamide, dimethyl sulphoxide, and acetonitrile. The Hammett substitution correlations have been calculated and interpreted for these media. The pKHA values measured and the results published earlier for methanol, ethanol, and water have been treated by multiple linear regresion using the published set of the parameters characterizing solvents and by factor analysis using the short cycle and the target testing method.

Solvent effects on dissociation of substituted benzenesulphonamides in acetone, 1,2-dichloroethane, tetramethylene sulphone, pyridine and some aqueous organic solvent mixtures

1986 ◽  
Vol 51 (9) ◽  
pp. 1948-1957 ◽  
Author(s):  
Miroslav Ludwig ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Organic Solvent ◽  
General Formula ◽  
Potentiometric Titration ◽  
Solvent Effects ◽  
Dissociation Constants ◽  
Dimethyl Sulphoxide ◽  
Organic Component ◽  
Solvent Mixtures

The potentiometric titration has been used to measure dissociation constants of fifteen substituted arenesulphonamides of general formula XC6H4SO2NH2 (or X2C6H3SO2NH2) in acetone, 1,2-dichloroethane, tetramethylene sulphone, pyridine, and mixtures water-ethanol (25, 50, 75, 90% by vol. of the organic component), water-dimethylformamide (25, 50, 75% by vol.), water-acetone (25% by vol.), and water-2-methoxyethanol (80% by wt.). The results are compared with those published earlier for water, methanol, ethanol, dimethylformamide, dimethyl sulphoxide, and acetonitrile.

Solvent Effect on the Dissociation Constants of Aliphatic Carboxylic Acids

1991 ◽  
Vol 44 (8) ◽  
pp. 1077 ◽  
Author(s):  
H Bartnicka ◽  
I Bojanowska ◽  
MK Kalinowski
Keyword(s):  
Solvent Effect ◽  
Dimethyl Sulfoxide ◽  
General Formula ◽  
Carboxylic Acids ◽  
Potentiometric Titration ◽  
Dissociation Constants ◽  
Solvent Polarity ◽  
P Values ◽  
Reaction Constants ◽  
Aliphatic Carboxylic Acids

Dissociation constants of 10 aliphatic carboxylic acids, of general formula R-COOH, were measured by potentiometric titration in acetonitrile, propylene carbonate, acetone, N,N- dimethylformamide and dimethyl sulfoxide. The p* reaction constants of the Taft equation were found to depend on the solvent polarity, whereas the influence of the Lewis basicity and acidity is negligible. The p* values determined earlier in water, methanol and nitromethane also fulfil this rule.

Determination of Co(II) and Ni(II)-humate stability constants at high ionic strength NaCl solutions

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
D.N. Kurk ◽  
Gregory R. Choppin
Keyword(s):  
Humic Acid ◽  
Ionic Strength ◽  
Solvent Extraction ◽  
Potentiometric Titration ◽  
Stability Constants ◽  
Dissociation Constants ◽  
High Ionic Strength ◽  
Extraction Technique ◽  
Solvent Extraction Technique

Complexation of Ni(II) and Co(II) by unfractionated humic acid (HA) was measured in 0.3 to 5.0 m NaCl solutions at pH 6 and 20 °C, using a solvent extraction technique. The dissociation constants and capacities of the humic acid were investigated in 0.1 to 5.0 m NaCl solutions at 25 °C using potentiometric titration methods.

Kinetic medium effects. III. Solvent effects on A1 and A2 Hydrolyses in water-dimethyl sulphoxide mixtures

1967 ◽  
Vol 20 (9) ◽  
pp. 1815 ◽  
Author(s):  
BG Cox ◽  
PT McTigue
Keyword(s):  
Ethyl Acetate ◽  
Solvent Effect ◽  
Activity Coefficients ◽  
Solvent Effects ◽  
Butyl Acetate ◽  
Solvent System ◽  
Solvent Composition ◽  
Dimethyl Sulphoxide ◽  
Medium Effects ◽  
System Activity

The relative rates of the concurrent A1 and A2 hydrolyses of t-butyl acetate have been measured as a function of solvent composition in water-dimethyl sulphoxide (DMSO) mixtures. A large difference in solvent effect is observed, which correlates well with observed solvent effects on ethyl acetate (A2) and acetal (Al) hydrolyses in the same solvent system. Activity coefficients have been measured for t-butyl acetate, ethyl acetate, and acetal in various water-DMSO mixtures.

Solvent effect on the dissociation of p-nitroanilinium ion in glycerol–water media at 25 °C

1984 ◽  
Vol 62 (11) ◽  
pp. 2245-2248
Author(s):  
Amrita Lal De ◽  
Tapas Kumar De
Keyword(s):  
Solvent Effect ◽  
Dissociation Constants ◽  
Mixed Solvents ◽  
Individual Species ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Monohydric Alcohol ◽  
Glycerol Water ◽  
Alcohol Water ◽  
The Individual

Thermodynamic dissociation constants (sK) of p-nitroanilinium ion (BH+) have been determined at 25 °C in aqueous mixtures of 10, 30, 50, 70, and 90 wt.% of glycerol (GL) by spectrophotometric measurements. Standard free energies, [Formula: see text], of p-nitroaniline (B) from water to mixed solvents have been evaluated from the measurement of solubilities at 25 °C. p(sK) values decrease with increase in mol% of GL and pass through a minimum and then increase very slowly. The solvent effect on the dissociation, δ(ΔG0) = 2.303RT [p(sK)N – p(wK)N] has been discussed in terms of the standard free energies of transfer [Formula: see text] from water to aqueous mixtures of GL of the uncharged base (B), the hydrochloride of the base (BHCl), hydrochloric acid (HCl), and also in terms of the individual species involved in the dissociation process. The solvent effect in trihydric alcohol – water (GL + H2O) system has been compared with those in dihydric alcohol – water (ethylene glycol + water) and monohydric alcohol – water (ethanol + water) systems available from literature. The much less solvent effect in GL + H2O has been primarily attributed to the contrasting nature of interaction of H+ and of partially charged H atoms of—NH3+ group in BH+ compared to those in other two solvent systems.

Solvent effect - Classification of parameters describing influence of solvents

1983 ◽  
Vol 48 (11) ◽  
pp. 3287-3306 ◽  
Author(s):  
Petr Svoboda ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Factor Analysis ◽  
Solvent Effect ◽  
Solvent Effects ◽  
Reaction Mechanisms ◽  
Chemical Processes ◽  
Point Of View ◽  
Regression Coefficients ◽  
Orthogonal Set ◽  
Influence Of Solvents

On the basis of factor analysis of data matrices containing 35 empirical and non-empirical parameters for 85 solvents (or a limited matrix of 20 parameters for 51 solvents), an orthogonal set of parameters with normed normal distribution has been suggested which characterizes influence of the solvents on chemical processes. A four-parameter equation has been suggested for description of the solvent effect in the form A = A0 + aAP + bBP + eEP + pPP, where AP, BP, EP, PP are newly introduced parameters expressing individual types of interactions between solvent and solute. A comparison has been carried out of these parameters with those defined earlier. The new set of parameters was tested with 22 examples taken from literature. The correlations obtained show higher or comparable agreement as compared with those carried out earlier. Values of the regression coefficients make it possible to discuss the reaction mechanisms from the point of view of solvent effects.

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