Hammett acidity function of water-salt solutions of strong acids

Author(s):  
S. G. Sysoeva ◽  
I. S. Kislina ◽  
M. I. Vinnik

1972 ◽  
Vol 50 (20) ◽  
pp. 3283-3287 ◽  
Author(s):  
T. T. Teng ◽  
F. Lenzi

Values of the Hammett acidity function H0 can be correlated for strong acid solutions up to −H0 values of 3.5 via a Bascombe and Bell type equation:[Formula: see text] taking into account the degree of dissociation of the acids. This can be interpreted according to[Formula: see text]and[Formula: see text]Alternatively, an approach based on the treatment of equilibrium constants in terms of mole-fractions yields[Formula: see text]valid for the same acids (H2SO4, HClO4, HCl, and HNO3) and again involving a tri-dehydration of the tetra-hydrated proton. The log of the ratio [Formula: see text] has been found to be proportional to −H0 itself and to be otherwise independent of the nature of the acid anion.



1960 ◽  
Vol 14 ◽  
pp. 1627-1642 ◽  
Author(s):  
Erik Högfeldt ◽  
Niels Hofman-Bang ◽  
Thor A. Bak ◽  
E. Varde ◽  
Gertrud Westin


2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi

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.



2017 ◽  
Vol 122 (3) ◽  
pp. 440-446 ◽  
Author(s):  
A. V. Voitylov ◽  
V. V. Voitylov ◽  
S. A. Klemeshev ◽  
M. P. Petrov ◽  
A. A. Trusov ◽  
...  


1962 ◽  
Vol 40 (5) ◽  
pp. 966-975 ◽  
Author(s):  
J. T. Edward ◽  
I. C. Wang

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.





1972 ◽  
Vol 50 (4) ◽  
pp. 581-583 ◽  
Author(s):  
Keith Yates ◽  
Stanley A. Shapiro

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.



2020 ◽  
Vol 91 (5) ◽  
pp. 348-353
Author(s):  
A. A. Panov ◽  
A. V. Patsino ◽  
V. A. Maslov ◽  
A. L. Panin ◽  
A. V. Polyudchenkov ◽  
...  


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