The Ionization Constant of Orthanilic Acid from 0 to 500 by Means of E.m.f. Measurements

1957 ◽  
Vol 61 (3) ◽  
pp. 333-336 ◽  
Author(s):  
R. Norman Diebel ◽  
D. F. Swinehart
1961 ◽  
Vol 65 (2) ◽  
pp. 264-267 ◽  
Author(s):  
H. L. Loy ◽  
D. M. Himmelblau

Author(s):  
E. A. Shaporova ◽  
A. A. Zhukova ◽  
A. K. Baev ◽  
A. Yu. Sidorenko

The article is devoted to the study of the nature and number of acid-base centers on the surface of chromium(III) oxide obtained by precipitation from an aqueous nitrate solution. The curve of the distribution of the number of acidbase centers of the samples is plotted depending on the indicator of the ionization constant of indicators. It was determined that the main Lewis centers make the main contribution to the acidity of the samples; there are also Bronsted centers of different acidity. A comparative analysis of the structural features of the surface of oxides of chromium, zinc and binary systems Cr (III)–Zn (II) was carried out according to the results of X-ray phase analysis of oxides and thermolysis of the corresponding hydroxides. Based on this, the possibility of obtaining nanosized catalysts based on oxide-hydroxide systems of chromium with a number of 3d-metals obtained in the process of polynuclear hydroxocomplexation is predicted.


Biochemistry ◽  
1965 ◽  
Vol 4 (12) ◽  
pp. 2832-2835 ◽  
Author(s):  
James Ofengand ◽  
Heidi Schaefer
Keyword(s):  

Author(s):  
Henderson James Jim Cleaves
Keyword(s):  

1931 ◽  
Vol 4 (4) ◽  
pp. 361-371
Author(s):  
Steward Basterfield ◽  
C. Vernon Wilson ◽  
Margaret E. Greig

Previous studies have shown that oxalyl-, malonyl- and phthalyldi-urethanes are decomposed readily by ammonia and primary amines with the loss of one or both urethane groups and the production of the amides of the dibasic acids, or of urethane-amides, and ureido-amides. Acyldi-ureas were not formed as might have been expected.The present study deals mainly with the preparation and properties of succinyl-, glutaryl-, and adipyldi-urethanes. While with ammonia and ethylamine these yield amides, with aniline they give the acyldi-(phenylureas), which are decomposed by further action of the base into acylanilides, and diphenylurea. The mode of decomposition is strongly influenced by the nature of the acyl radical as well as that of the reacting base. The results may be provisionally generalized in the statement that, with a given base, the tendency of a di-urethane to yield the acid amide is more pronounced the stronger the acid from which the radical is derived, while with a given di-urethane the tendency to amide formation is more pronounced the stronger the reacting base. The formation of acyldi-ureas becomes evident when the di-urethane contains the radical of an acid with an ionization constant of the order of 10−6 or less.


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