Acidity Inversions of α-NO2and α-SO2CF3Activated Carbon Acids as a Result of Contrasting Solvent Effects on Transfer from Water to Dimethyl Sulfoxide Solutions

2003 ◽  
Vol 68 (17) ◽  
pp. 6566-6570 ◽  
Author(s):  
Régis Goumont ◽  
Emmanuel Magnier ◽  
Elyane Kizilian ◽  
François Terrier
Keyword(s):  
Dimethyl Sulfoxide ◽  
Solvent Effects ◽  
Carbon Acids

The application of the Hammett equation to 13C N.M.R. spectrometry. IV. Solvent effects

1982 ◽  
Vol 35 (1) ◽  
pp. 21 ◽  
Author(s):  
DAR Happer
Keyword(s):  
Carbon Tetrachloride ◽  
Dimethyl Sulfoxide ◽  
Solvent Effects ◽  
Aqueous Ethanol ◽  
Chemical Shifts ◽  
Hammett Equation ◽  
Solvent Dependence ◽  
Ethanol Ethanol ◽  
Vinyl Group

The chemical shifts for Cβ of the vinyl group of styrene and 16 of its meta-or para-substituted derivatives have been measured in seven solvents: 75% aqueous ethanol, ethanol, dimethyl sulfoxide, acetone, deuterochloroform, carbon tetrachloride and benzene. Attempts have been made to correlate the data by means of the Hammett equation, discrepancies being discussed in terms of solvent dependence of σ and p.

Solute–solvent effects in the dissociation of thymolsulfonephthalein (an uncharged acid) in aqueous mixtures of acetonitrile (ACN), urea, and dimethyl sulfoxide (DMSO)

1986 ◽  
Vol 64 (8) ◽  
pp. 1521-1526 ◽  
Author(s):  
A. L. De ◽  
A. K. Atta
Keyword(s):  
Solvent Effect ◽  
Dimethyl Sulfoxide ◽  
Solvent Effects ◽  
Mixed Solvent ◽  
Dissociation Constants ◽  
Aqueous Mixtures ◽  
Solvent Interactions ◽  
Gibbs Energies ◽  
Gibbs Energies Of Transfer ◽  
Solvent Systems

The thermodynamic first dissociation constants, [Formula: see text] of thymolsulfonephthalein (H2A), an uncharged acid, have been determined at 25 °C in aqueous mixtures of 10, 30, 50, 70, and 80 wt% acetonitrile (ACN), 11.52, 20.31, 29.64, and 36.83 wt% urea, 20, 40, 60, and 80 wt% dimethyl sulfoxide (DMSO) by spectrophotometric measurements. The solvent effect represented by ∂(ΔG0) = 2.303RT[p(sK)N − p(wK)N] is found to increase in ACN + H2O system as mol% ACN increases in the solvent. In contrast, the corresponding values in urea + H2O as well as DMSO + H2O solvent systems decrease with increase in proportion of organic component in the solvent, the decrease being sharp in urea + H2O. The results have been discussed in terms of the standard Gibbs energies of transfer of H+ from water to the mixed solvent, [Formula: see text] and the relative values of the standard Gibbs energies of transfer of HA−, [Formula: see text] and of [Formula: see text] in all the solvent systems. The overall dissociation behaviour of the acid (H2A) is found to be dictated by the specific solute-solvent interactions of the species participating in the dissociation equilibria.

Free energy relationship of the equilibrium ionization constants of disulfonyl carbon acids in 80% (w/w) dimethyl sulfoxide – water solvent at 25°C

1979 ◽  
Vol 57 (8) ◽  
pp. 853-855 ◽  
Author(s):  
Thomas W. S. Lee ◽  
Kok-Peng Ang
Keyword(s):  
Dimethyl Sulfoxide ◽  
Negative Charge ◽  
Substituent Effects ◽  
Ionization Constants ◽  
Spectrophotometric Measurement ◽  
Water Solvent ◽  
Benzylic Carbon ◽  
Carbon Acids ◽  
Substituted Toluenes ◽  
Relationship Of

A series of eight carbon acids, α,α-bis(benzylsulfonyl)toluene and 7 substituted α,α-bis-(benzylsulfonyl)toluenes, was synthesized and their equilibrium ionization constants were determined by spectrophotometric measurement in 80% (w/w) dimethyl sulfoxide – water solvent at 25 °C. From a plot of −log K versus σ for the 'well-behaved' substituents and σ− for para-cyano and para-nitro substituents, a ρ value of 2.53 is obtained. The correlation co-efficient is 0.99. Comparing this ρ value with the reported ρ value of 12 for the substituted toluenes in dimethyl sulfoxide, it shows that the acidities of the disulfonyl toluenes are at least 8 to 9 orders of magnitude less sensitive to substituent effects than are the acidities of substituted toluenes implying that, for disulfonyl toluenes, the negative charge on the benzylic carbon is extensively delocalised into the two adjacent sulfonyl groups.

Acidities of carbon acids. V. Correlation of acidities in dimethyl sulfoxide with gas-phase acidities

1975 ◽  
Vol 97 (11) ◽  
pp. 3226-3227 ◽  
Author(s):  
F. G. Bordwell ◽  
John E. Bartmess ◽  
George E. Drucker ◽  
Zafra Margolin ◽  
Walter S. Matthews
Keyword(s):  
Dimethyl Sulfoxide ◽  
Gas Phase ◽  
Carbon Acids

ChemInform Abstract: ACIDITIES OF CARBON ACIDS PART 5, CORRELATION OF ACIDITIES IN DIMETHYL SULFOXIDE WITH GAS-PHASE ACIDITIES

1975 ◽  
Vol 6 (33) ◽  
Author(s):  
F. G. BORDWELL ◽  
JOHN E. BARTMESS ◽  
GEORGE E. DRUCKER ◽  
ZAFRA MARGOLIN ◽  
WALTER S. MATTHEWS
Keyword(s):  
Dimethyl Sulfoxide ◽  
Gas Phase ◽  
Carbon Acids
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