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.

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.

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

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
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