Protonation of conjugated carbonyl groups in sulfuric acid solutions. II. Protonation and basicity of α,β-unsaturated alicyclic ketones

1969 ◽  
Vol 47 (12) ◽  
pp. 2263-2270 ◽  
Author(s):  
R. I. Zalewski ◽  
G. E. Dunn
Keyword(s):  
Sulfuric Acid ◽  
Substituent Effects ◽  
Acidity Function ◽  
Acid Solutions ◽  
Carbonyl Groups ◽  
Resonance Effects ◽  
Unit Slope ◽  
Straight Lines ◽  
Sulfuric Acid Solutions

The protonation of 14 α,β-unsaturated alicyclic ketones, B, by sulfuric acid leads to values of log [B]/[BH+] which, when plotted against the amide acidity function, HA, give straight lines of unit slope. The [Formula: see text] values thus obtained show substituent effects which are additive and can be interpreted in terms of polar and resonance effects.

Protonation of conjugated carbonyl groups in sulfuric acid solutions. III. α,β-Unsaturated ketosteroids

1970 ◽  
Vol 48 (16) ◽  
pp. 2538-2541 ◽  
Author(s):  
R. I. Zalewski ◽  
G. E. Dunn
Keyword(s):  
Sulfuric Acid ◽  
Spectral Data ◽  
Acidity Function ◽  
Additive Effects ◽  
Acid Solutions ◽  
Carbonyl Groups ◽  
Ultraviolet Spectrophotometry ◽  
Unit Slope ◽  
Straight Lines ◽  
Sulfuric Acid Solutions

Protonation of 20 α,β-unsaturated ketosteroids by sulfuric acid was studied by ultraviolet spectrophotometry. Plots of log [B]/[BH+] from spectral data against the amide acidity function, HA, gave straight lines with unit slope. The pKBH+ values thus obtained show the same additive effects of substituents as that reported previously for simple α,β-unsaturated alicyclic ketones.

Substituent Effects on the Hydrolysis of p-Substituted Benzonitriles in Sulfuric Acid Solutions at (25.0± 0.1) °C

2008 ◽  
Vol 63 (9) ◽  
pp. 603-608 ◽  
Author(s):  
Khamis A. Abbas
Keyword(s):  
Sulfuric Acid ◽  
Rate Constants ◽  
Inductive Effect ◽  
Substituent Effects ◽  
Acid Solutions ◽  
Rate Determining Step ◽  
Inductive Effects ◽  
High Concentrations ◽  
Sulfuric Acid Solutions ◽  
Hydrolysis Of

The rate constants of the hydrolysis of p-substituted benzonitriles with sulfuric acid solutions (18.2 M to 10 M) have been determined spectrophotometrically at (25.1±0.1) °C. It was found that the catalytic activity of sulfuric acid was strongly inhibited by water. The logarithms of the observed rate constants were correlated with different substituent inductive (localized) and resonance (delocalized) constants. The results of the correlation studies indicated that the rate-determining step of the hydrolysis of benzonitriles in 18.2 M sulfuric acid was the addition of a nucleophile, and the hydrolysis was clearly enhanced by the electron-withdrawing inductive effect, while the rate-determining step of the hydrolysis of p-substituted benzonitriles in 10.0 M sulfuric acid was most probably the protonation of benzonitriles, and the rate constants increased by both electron-donating resonance and inductive effects. A mixture of the two mechanisms most probably occurred in 15.3 to 17.0 M sulfuric acid. HSO4 − rather thanwater most probably acted as nucleophile in the hydrolysis of benzonitriles especially at high concentrations of sulfuric acid solutions.

The ketonization of acetophenone enol in concentrated aqueous sulphuric and perchloric acid solutions. Implication on X acidity function correlations of the enolization reaction and determination of the keto–enol equilibrium constant as a function of acidity

1990 ◽  
Vol 68 (10) ◽  
pp. 1653-1656 ◽  
Author(s):  
Y. Chiang ◽  
A. J. Kresge ◽  
R. A. More O'ferrall ◽  
B. A. Murray ◽  
N. P. Schepp ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Key Words ◽  
Equilibrium Constant ◽  
Perchloric Acid ◽  
Acidity Function ◽  
Acid Solutions ◽  
Function Correlation ◽  
Aqueous Perchloric Acid ◽  
Sulfuric Acid Solutions

Rates of ketonization of the enol of acetophenone, generated by flash photolytic photohydration of phenylacetylene, were measured in aqueous sulfuric and perchloric acid solutions over the concentration range 1–50 wt.% acid; rates of enolization of acetophenone, monitored by bromine scavenging, were also measured in aqueous perchloric acid solutions over the same concentration range. The results suggest that the curvature observed in a previous X acidity function correlation of the rate of enolization in sulfuric acid solutions was an artifact produced by insufficiently efficient scavenging, and that introduction of the activity of water in the correlating expression, used previously to eliminate the curvature and believed to reflect covalent involvement of water in the enolization reaction, is unnecessary. The present results also show that the keto–enol equilibrium constant for acetophenone decreases with increasing acidity in these concentrated sulfuric and perchloric acid solutions. Key words: acetophenone, enolization, ketonization, keto–enol equilibrium, concentrated acid solutions.

Acid-catalyzed enolization of acetophenone: catalysis by bisulfate ion in sulfuric acid solutions

1986 ◽  
Vol 64 (6) ◽  
pp. 1224-1227 ◽  
Author(s):  
J. R. Keeffe ◽  
A. J. Kresge ◽  
J. Toullec
Keyword(s):  
Aqueous Solution ◽  
Sulfuric Acid ◽  
Acidity Constant ◽  
Acidity Function ◽  
Acid Solutions ◽  
Dilute Aqueous Solution ◽  
Acid Catalyzed ◽  
The Difference ◽  
Carbon Acid ◽  
Sulfuric Acid Solutions

Rates of acid-catalyzed enolization of acetophenone in dilute aqueous solution, measured under conditions where the solvated proton is the only acidic species present, give a hydrogen ion catalytic coefficient, [Formula: see text], that is 35% smaller than the value obtained by X acidity function extrapolation of measurements made in moderately concentrated sulfuric acid solutions. The difference may be attributed to catalysis by bisulfate ion in the sulfuric acid solutions; this is supported by direct measurement of the bisulfate ion catalytic coefficient in dilute sulfuric acid. This revised value of [Formula: see text] leads to new, but only slightly different, values of the keto–enol equilibrium constant for acetophenone in aqueous solution, pKE = 7.96 ± 0.04, the acidity constant for acetophenone ionizing as a carbon acid, [Formula: see text] and the encounter-controlled rate constant for the reaction of acetophenone enol with molecular bromine, k = (3.2 ± 0.4) × 109 M−1 s−1.

Protection features of chromium-nickel steel in sulfuric acid solutions by triazole derivative

2019 ◽  
pp. 15-21
Author(s):  
Ya.G. Avdeev ◽  
◽  
Yu.B. Makarychev ◽  
D.S. Kuznetsov ◽  
L.P. Kazanskii ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Nickel Steel ◽  
Acid Solutions ◽  
Triazole Derivative ◽  
Sulfuric Acid Solutions

Rheological Characterization of Sulfuric Acid Solutions of Poly(p-phenyleneterephthalamide)

1987 ◽  
Vol 2 (1) ◽  
pp. 28-32 ◽  
Author(s):  
B. C. Kim ◽  
S. S. Hwang ◽  
K. U. Kim
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Rheological Characterization ◽  
Sulfuric Acid Solutions

Electrochemistry of Gold in Aqueous Sulfuric Acid Solutions under Neural Stimulation Conditions

2005 ◽  
Vol 152 (7) ◽  
pp. E212 ◽  
Author(s):  
Daniel R. Merrill ◽  
Ionel C. Stefan ◽  
Daniel A. Scherson ◽  
J. Thomas Mortimer
Keyword(s):  
Sulfuric Acid ◽  
Neural Stimulation ◽  
Acid Solutions ◽  
Aqueous Sulfuric Acid ◽  
Sulfuric Acid Solutions

Separation of lanthanum(III), gadolinium(III) and ytterbium(III) from sulfuric acid solutions by using a polymer inclusion membrane

2018 ◽  
Vol 545 ◽  
pp. 259-265 ◽  
Author(s):  
Charles F. Croft ◽  
M. Inês G.S. Almeida ◽  
Robert W. Cattrall ◽  
Spas D. Kolev
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Inclusion Membrane ◽  
Polymer Inclusion Membrane ◽  
Sulfuric Acid Solutions
Sign in / Sign up

Export Citation Format

Share Document