A Critical Re-evaluation of the Hammett Acidity Function at Moderate and High Acid Concentrations of Sulfuric Acid. NewH0Values Based Solely on a Set of Primary Aniline Indicators

1963 ◽  
Vol 85 (7) ◽  
pp. 878-883 ◽  
Author(s):  
Margaret Jefraim. Jorgenson ◽  
Donald R. Hartter
Keyword(s):  
Sulfuric Acid ◽  
Acidity Function ◽  
High Acid ◽  
Hammett Acidity Function

A Critical Test of the Hammett Acidity Function

1972 ◽  
Vol 50 (4) ◽  
pp. 581-583 ◽  
Author(s):  
Keith Yates ◽  
Stanley A. Shapiro
Keyword(s):  
Sulfuric Acid ◽  
Aromatic Amines ◽  
Acidity Function ◽  
Experimental Uncertainty ◽  
Critical Test ◽  
Hammett Acidity Function ◽  
Primary Aromatic Amines

The applicability of the H0 acidity function to primary aromatic amines in general has been tested by using a set of five aniline indicators bearing no nitro-substituents. Up to 45% sulfuric acid the scale generated by these bases is the same (within experimental uncertainty) as that based entirely on nitro-anilines.

Protonation of polyacid organic bases. III. Hammett acidity function H+ for aqueous sulfuric acid

1968 ◽  
Vol 33 (6) ◽  
pp. 1687-1692 ◽  
Author(s):  
P. Vetešník ◽  
J. Bielavský ◽  
M. Večeřa
Keyword(s):  
Sulfuric Acid ◽  
Acidity Function ◽  
Organic Bases ◽  
Aqueous Sulfuric Acid ◽  
Hammett Acidity Function

Preparation and Characterization of a Novel Room Temperature Dicationic Ionic Liquid and its Application in the Synthesis of Xanthenediones Under Solvent-Free Conditions

2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Reaction Times ◽  
Significant Loss ◽  
Solvent Free ◽  
Acidity Function ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Hammett Acidity Function ◽  
Dicationic Ionic Liquid

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.

IONIZATION OF ORGANIC COMPOUNDS: III. BASICITIES OF PROPIONIC ACID AND PROPIONAMIDE

1962 ◽  
Vol 40 (5) ◽  
pp. 966-975 ◽  
Author(s):  
J. T. Edward ◽  
I. C. Wang
Keyword(s):  
Sulphuric Acid ◽  
Propionic Acid ◽  
Organic Compounds ◽  
Acid Concentration ◽  
Ultraviolet Absorption ◽  
Protonation Constants ◽  
Acidity Function ◽  
Hammett Acidity Function ◽  
Ionization Ratio

Protonation constants (pKBH+) of −6.8 and −0.9 have been determined for propionic acid and propionamide, respectively, from measurements of their ultraviolet absorption in various concentrations of sulphuric acid. The ionization ratio of propionamide and of other amides increases more slowly than the Hammett acidity function, h0, with increase in acid concentration. This may be explained by assuming that in a given concentration of sulphuric acid the protonated amide is more heavily hydrated than the protonated Hammett indicator used to establish the h0 scale for this region of acid concentrations.

scholarly journals The Hammett Acidity Function H0 of Trifluoromethanesulfonic Acid-Trifluoroacetic Acid and Related Acid Systems. A Versatile Nonaqueous Acid System.

1991 ◽  
Vol 39 (10) ◽  
pp. 2718-2720 ◽  
Author(s):  
Shoichi SAITO ◽  
Shin-ichi SAITO ◽  
Tomohiko OHWADA ◽  
Koichi SHUDO
Keyword(s):  
Trifluoroacetic Acid ◽  
Trifluoromethanesulfonic Acid ◽  
Acidity Function ◽  
Acid System ◽  
Hammett Acidity Function

The Hammett Acidity Function H0for Trifluoroacetic Acid Solutions of Sulfuric and Hydrofluoric Acids1

1959 ◽  
Vol 81 (8) ◽  
pp. 1847-1849 ◽  
Author(s):  
Herbert H. Hyman ◽  
Ronald A. Garber
Keyword(s):  
Trifluoroacetic Acid ◽  
Acidity Function ◽  
Acid Solutions ◽  
Hammett Acidity Function

Anchoring of the amide acidity function in dilute aqueous acid: a corrected HA scale

1977 ◽  
Vol 55 (13) ◽  
pp. 2492-2494 ◽  
Author(s):  
John T. Edward ◽  
Sin Cheong Wong
Keyword(s):  
Sulfuric Acid ◽  
Acidity Function ◽  
Aqueous Acid

Amide indicators ionizing over the range 0–30% sulfuric acid indicate that values of the HA scale established by Yates etal. (Can. J. Chem. 42, 1957 (1964)) should be corrected by +0.33 unit.

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