Modification of reaction rates by complex formation. IV. Interactant structure and complex stability for complexes of theophylline with cinnamate esters and related compounds in aqueous solution

1969 ◽  
Vol 91 (13) ◽  
pp. 3597-3603 ◽  
Author(s):  
Kenneth A. Connors ◽  
Martin H. Infeld ◽  
Berry J. Klin
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Reaction Rates ◽  
Complex Stability ◽  
Related Compounds

Uranium(VI) complexes with sugar phosphates in aqueous solution

2004 ◽  
Vol 92 (12) ◽  
Author(s):  
A. Koban ◽  
Gerhard Geipel ◽  
A. Roßberg ◽  
G. Bernhard
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Potentiometric Titration ◽  
Stability Constants ◽  
Complex Stability ◽  
Aqueous Systems ◽  
Ligand Ratio ◽  
Sugar Phosphates ◽  
Complex Stability Constants

SummaryThe complex formation in the aqueous systems of uranium(VI) with glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P) were studied using potentiometric titration, TRLFS, and EXAFS. Two complexes with a uranyl-to-ligand ratio of 1:1 and 1:2 for both sugars were observed. Complex stability constants were determined by potentiometric titration for both complexes to be log βThe TRLFS measurements results show the UOUranium

Stability constants for metal complexation by isomers of mimosine and related compounds

1980 ◽  
Vol 33 (10) ◽  
pp. 2207 ◽  
Author(s):  
H Stunzi ◽  
LN Harris ◽  
DD Perrin ◽  
T Teitei
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Blood Plasma ◽  
Stability Constants ◽  
Complexing Agent ◽  
Propanoic Acid ◽  
Metal Chelation ◽  
Plasma Model ◽  
Physiological Conditions ◽  
Related Compounds

Stability constants for the Mg2+, Ca2+, Cu2+ and Zn2+ complexes of two isomers (2) and (3) of the defleecing agent mimosine (1) have been sought from potentiometric titrations in aqueous solution, 0.15 M KNO3, at 37°. For the interpretation of the results, complex formation of the simpler ligands 3-hydroxypyridin-4(1H)-one (4), its 2-oxo isomer (5) and DL-α-amino-β-(6-oxo-1,6-dihydropyridin-2-yl)propanoic acid (6) was studied. The results with ligand (2) are very similar to those with mimosine, for which a computer blood-plasma model indicates metal chelation under physiological conditions. Ligand (3) is a much weaker complexing agent.

Bis(monoazacrown ethers) with an electron-donating substituent at the hinge: A pronounced participation of hydroxyl group in formation of sodium ion sandwich complexes

1989 ◽  
Vol 54 (4) ◽  
pp. 1043-1054 ◽  
Author(s):  
Jiří Závada ◽  
Juraj Koudelka ◽  
Petr Holý ◽  
Martin Bělohradský ◽  
Ivan Stibor
Keyword(s):  
Complex Formation ◽  
Sandwich Structure ◽  
Sodium Ion ◽  
Hydroxyl Group ◽  
Complex Stability ◽  
Sandwich Complexes ◽  
Sandwich Complex ◽  
Marked Enhancement ◽  
Stability Data ◽  
Potentiometric Data

Sodium ion complex formation has been investigated potentiometrically in four homologous bis(crown) series I-IV differing by the nature of substituent placed at the linking trimethylene chain (X = OH, OCH3, OCH2C6H5 and H respectively). A marked enhancement of the complex stability has been observed in the bis(crown) series I and attributed to participation of the lateral hydroxyl group in the sandwich complex formation. Evidence in support of the sandwich structure has been provided (i) by analysis of the potentiometric data indicating a 1:1 complex stoichiometry and (ii) by a comparison of the complex stability data from the bis(crown) series I with the corresponding values from related monocyclic ligand series V, VI and VII revealing a pronounced cooperation of both macrorings in the sodium ion-bis(crown) I complex formation.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

Complex Formation in the Ternary System Tl(III)−CN-−Cl-in Aqueous Solution. A205Tl NMR Study

1996 ◽  
Vol 35 (24) ◽  
pp. 7074-7081 ◽  
Author(s):  
Katja E. Berg ◽  
Johan Blixt ◽  
Julius Glaser
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Ternary System ◽  
Nmr Study
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