Formation et stabilité de complexes hydroxo–ammonio en solution aqueuse. I. Complexes de zinc

1968 ◽  
Vol 46 (10) ◽  
pp. 1707-1714 ◽  
Author(s):  
A. O. Gubeli ◽  
J. Ste-Marie
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Formation Constants ◽  
New Method ◽  
Hydroxo Complexes ◽  
Solution Aqueuse

A new method has been developed for the calculation of the formation constants of complexes in equilibrium with a precipitate in aqueous solution. This has been applied to the study of ammonio and ammonio–hydroxo complexes of zinc in the presence of the hydroxide. The curves of solubility vs. pH and pNH3 tot have been established by means of 65Zn at 25 °C and ionic strength 1.0 with NaClO4.

scholarly journals Precipitation and Hydrolysis of Thorium in Aqueous Solution. VI. Determination of Formation Constants for Mixed Thorium-Maleate-Hydroxo Complexes and Characterization of Solids.

1985 ◽  
Vol 39a ◽  
pp. 317-325 ◽  
Author(s):  
Halka Bilinski ◽  
Staffan Sjöberg ◽  
Sanja Kežić ◽  
Nevenka Brničević ◽  
Francesco Salvatore
Keyword(s):  
Aqueous Solution ◽  
Formation Constants ◽  
Hydroxo Complexes ◽  
Hydrolysis Of

Coordinating Properties of Aromatic and Aliphatic Sulfur with Bivalent Metals in Aqueous Solution. A Calorimetric Study

1979 ◽  
Vol 32 (4) ◽  
pp. 709 ◽  
Author(s):  
R Aruga
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Complex Formation ◽  
Aqueous Medium ◽  
Formation Constants ◽  
Calorimetric Study ◽  
Thermodynamic Quantities ◽  
Direct Calorimetry ◽  
Bivalent Metals

Heats and entropies of complex formation of the thiophen-2-carboxylate ion with Ni2+, Cu2+, Zn2+ and Cd2+ have been determined by direct calorimetry, the formation constants being known from the literature. The measurements were carried out in aqueous medium at 25�C and an ionic strength of 1. The values of the thermodynamic quantities for thiophen-2-carboxylate, compared with those for (ethylthio)acetate and (phenylthio)acetate obtained previously, indicate a greater tendency for aromatic sulfur to form bonds with the above metals than for aliphatic sulfur. The causes of this behaviour are discussed.

scholarly journals Vanadium(III) binding strengths of small biomolecules

2005 ◽  
Vol 77 (9) ◽  
pp. 1583-1594 ◽  
Author(s):  
Péter Buglyó ◽  
Eszter Márta Nagy ◽  
Imre Sóvágó
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Ionic Strength ◽  
Metal Ion ◽  
Donor Ligands ◽  
Spectroscopic Techniques ◽  
Hydroxo Complexes ◽  
Similarities And Differences ◽  
Small Biomolecules ◽  
Hydrolysis Of

The hydrolysis of vanadium(III) and the complex formation reactions between V(III) and weakly coordinating [glycine (GLY), DL-aspartic acid (ASP), D-penicillamine (PEN), DL-histidine (HIS)] or strongly coordinating [N,O] donor [picolinic (PIC) or 6-methylpicolinic acid (MePIC)] and [O,O] donor [maltol (MALT), 1,2-dimethyl-3-hydroxy-4-(1H)-pyridinone (DHP), tiron (TIR)] ligands were studied at 25.0 °C and an ionic strength of 0.20 M (KCl) in aqueous solution using combined pH-potentiometric and UV-vis spectroscopic techniques. Although some interaction between the amino acids and V(III) was found, we could not obtain reliable models for these systems owing to the intensive hydrolysis of the metal ion and the formation of polynuclear hydroxo complexes. With pyridine carboxylates or [O,O] donor ligands 1:1, 1:2 (in the latter case, also 1:3 species) were found to be present as major complexes in solution. The similarities and differences in binding V(III) by these ligands are discussed.

scholarly journals Interaction of Dioxovanadium (V) ion with L-alanine at Different Ionic Strengths

2009 ◽  
Vol 5 (1) ◽  
pp. 570-574
Author(s):  
Mohammad Hossein Fekri ◽  
F. Gharib ◽  
M. Darvishpour
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Stability Constants ◽  
Least Squares Method ◽  
Type Equation ◽  
Formation Constants ◽  
Amino Group ◽  
Fitting Method ◽  
The Stability ◽  
Curve Fitting Method

The formation constants of species formed in the system H+ + alanine and VO2+ +alanine have been determined in aqueous solution for 1.0<pH<7.0 and at different ionic strengths ranging from 0.1 to 1.0 mol dm-3 NaClO4, using a combination of potentiometric and spectrophotometric techniques.The compositions of the formd complexes and their stability constants were determined by curve fitting method and it was shown that dioxivanadium(V) forms two mononuclear 1:1 and 1:2 species with alanineof type VO2L and VO2L2-.The porotonation constant of the amino group of alanine has been determined using potentiometric techniques and calculated using a computer program wich employ a least-squares method. The dependence of the porotonation of alanine and the stability constants of the species on ionic strength are described by a deby-huckel type equation.

Chelation Reactions of Adenine

1972 ◽  
Vol 27 (6) ◽  
pp. 688-690 ◽  
Author(s):  
Ram Nayan ◽  
Arun K. Dey
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Metal Ions ◽  
Formation Constants ◽  
Ph Titration ◽  
Ionic Concentrations ◽  
Antimitotic Drug ◽  
Titration Technique

Chelation reactions of the antimitotic drug, 6-amino-purine (adenine; abbr. ADN) with the metal ions: Be(II), Al(III), Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Pb(II), and UO2(II) have been investigated in aqueous solution at 30° using Bjerrum-Calvin pH titration technique. The formation constants have been determined at various ionic concentrations, and have been extrapolated to zero ionic strength to get the thermodynamic values of the constants.

Stabilité des complexes hydroxo et produits de solubilité des hydroxydes de métaux. I. Argent et zinc

1967 ◽  
Vol 45 (8) ◽  
pp. 827-832 ◽  
Author(s):  
A. O. Gubeli ◽  
J. Ste-Marie
Keyword(s):  
Ionic Strength ◽  
Formation Constants ◽  
Hydroxo Complexes ◽  
Solubility Products

The hydroxo-complexes of silver and zinc are determined from a plot of their hydroxide solubility curves vs. pH, at 25 °C and unit ionic strength (NaClO4). The hydroxide solubility products and the formation constants of AgOH, Ag(OH)2−, ZnOH+, Zn(OH)2, Zn(OH)3−, and Zn(OH)42− are calculated.

Interaction of dimethyltin(IV)dichloride with 5′-AMP and 5′-GMP

2006 ◽  
Vol 84 (11) ◽  
pp. 1534-1540 ◽  
Author(s):  
Farrokh Gharib ◽  
Elnaz Farzad ◽  
Mostafa Mohammadpour Amini
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Ftir Spectroscopy ◽  
Constant Temperature ◽  
Elemental Analysis ◽  
Formation Constants ◽  
Low Ph ◽  
Ph Values ◽  
Species Formation ◽  
Ph Range

The formation constants of the species formed in the systems H+ + dimethyltin(IV) + 5′-AMP and 5′-GMP, H+ + 5′-AMP, and H+ + 5′-GMP have been determined in aqueous solution in the pH range of 1.5–9 at constant temperature (25 °C) and constant ionic strength (0.1 mol dm–3, NaClO4) using spectrophotometric and potentiometric techniques. 1H and 31P NMR investigations in aqueous solution confirmed the species formation and led us to propose their structures. The precipitated complexes of AMP and GMP by Me2Sn(IV)2+ at low pH values were characterized by elemental analysis and FTIR spectroscopy, which ruled out purine moiety (N-1 and N-7) coordination and a bidentated coordination of the phosphate group is concluded in both cases.Key words: dimethyltin(IV)dichloride, guanosine 5′-monophosphate, adenosine 5′-monophosphate, stability and protonation constants.

Meso tetrakis ortho-, meta-, and para-N-alkylpyridiniopor-phyrins: kinetics of copper(II) and zinc(II) incorporation and zinc porphyrin demetalation

2003 ◽  
Vol 07 (03) ◽  
pp. 139-146 ◽  
Author(s):  
Peter Hambright ◽  
Ines Batinić-Haberle ◽  
Ivan Spasojević
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Effective Charge ◽  
Methyl Ethyl ◽  
Ionic Strength Dependence ◽  
Zinc Porphyrin ◽  
Cationic Porphyrin ◽  
Strength Dependence ◽  
Acid Catalyzed ◽  
Kinetics Of

The relative reactivities of the tetrakis( N -alkylpyridinium- X - yl )-porphyrins where X = 4 (alkyl = methyl, ethyl, n -propyl) , X = 3 (methyl) , and X = 2 (methyl, ethyl, n -propyl, n -butyl, n -hexyl, n -octyl) were studied in aqueous solution. From the ionic strength dependence of the metalation rate constants, the effective charge of a particular cationic porphyrin was usually larger when copper(II) rather than zinc(II) was the reactant. The kinetics of ZnOH + incorporation and the acid catalyzed removal of zinc from the porphyrins in 1.0 M HCl were also studied. In general, the more basic 4- (para-) and 3- (meta-) isomers were the most reactive, followed by the less basic 2- (ortho-) methyl to n -butyl derivatives, with the lipophilic ortho n -hexyl and n -octyl porphyrins the least reactive.

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