Study of Complex Formation between 4-(2-Pyridylazo) Resorcinol and Al3+, Fe3+, Zn2+, and Cd2+Ions in an Aqueous Solution at 0.1 M Ionic Strength

2007 ◽  
Vol 52 (4) ◽  
pp. 1171-1178 ◽  
Author(s):  
J. Ghasemi ◽  
H. Peyman ◽  
M. Meloun
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Complex Formation

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 A Solution Study of Complex Formation of Some Diamines with Lanthanones

2009 ◽  
Vol 6 (1) ◽  
pp. 270-272 ◽  
Author(s):  
J. J. Vora ◽  
D. R. Patel ◽  
Asha D. Patel ◽  
Kanu Patel ◽  
Sangita Sharma ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Complex Formation ◽  
Metal Complex ◽  
Steric Effect ◽  
Ring Size ◽  
Titration Method ◽  
The Stability ◽  
Diamine Ligands ◽  
Metal Ligand

To study the metal ligand equilibrium in aqueous solution, the well known Irving-Rossotti titration method was used. The temperature selected is 30±0.10C at ionic strength 0.2 M (NaClO4) which was maintained constant through out the work. The binary metal complex (ML2) formation was studied. The metals selected are Sm3+, Gd3+, Dy3+and Yb3+. The diamine ligands taken are ethylenediamine, 1,2 diamino propane, 1,3 diamino propane,N-Ndiethyl ethylenediamine andN-N -dimethyl ethylenediamine. Factors that affected the stability of the complexes are size and ionic potential of lanthanone ions, basicity of ligands, ring size and steric effect of ligands.

Formation of Copper(II) Complexes of 1,3-Diamino-2-propanol in Aqueous Solution

1978 ◽  
Vol 33 (1) ◽  
pp. 59-61 ◽  
Author(s):  
Lauri H.J. Lajunen ◽  
Raikko Kivekäs
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Complex Formation ◽  
Constant Ionic Strength ◽  
Standard Deviations

Abstract The complex formation between Cu2+ ions and 1,3-diamino-2-propanol has been studied potentiometrically at 25 °C, constant ionic strength equal to 0.1 M NaClO4, and pH 5-11. The nature of the complexes has been established by examining the standard deviations and values of the agreement index R of different models.

Kinetic and Thermodynamic Studies of the Reactions of Sulfite Ion with Picramide, N-Methylpicramide, and N,N-Dimethylpicramide in Aqueous Solution

1974 ◽  
Vol 52 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Erwin Buncel ◽  
Albert Richard Norris ◽  
Kenneth Edwin Russell ◽  
Peter Jura Sheridan
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Complex Formation ◽  
Equilibrium Constants ◽  
Specific Rate ◽  
Stopped Flow ◽  
Primary Role ◽  
Kinetics Of ◽  
Kinetic And Thermodynamic Studies ◽  
Sulfite Ion

The kinetics of the reactions between sulfite ion and picramide, N-methylpicramide, and N,N-dimethylpicramide, to form 1:1 σ-complexes in aqueous solutions of constant ionic strength 0.14 M, have been investigated using a stopped-flow spectrophotometer. Specific rate constants for the formation and decomposition of these three complexes at 25.0 °C are 5.7 ± 0.2 × 104M−1 s−1 and 7 ± 1 s−1, 1.4 ± 0.1 × 104M−1 s−1 and 0.20 ± 0.02 s−1, and 4.1 ± 0.2 × 103M−1 s−1 and 0.14 ± 0.04 s−1, respectively. Enthalpies and entropies of activation characterizing the formation of the 1:1 σ-complexes have been determined. Equilibrium constants, determined spectrophotometrically at a number of temperatures, have been used to calculate the enthalpy (ΔH0) and entropy (ΔS0) changes associated with 1:1 and 2:1 σ-complex formation. These values are compared with corresponding ones for complex formation of sulfite ion with 1,3,5-trinitrobenzene and 2,4,6-trinitrobenzaldehyde. The extent of solvation of the σ-complexes is considered to play a primary role in determining the observed trends in the enthalpies and entropies of reaction.

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.

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.

Determination of the complexation properties of a crosslinked poly(acrylic acid) gel with copper(II), nickel(II), and lead(II) in dilute aqueous solution

2001 ◽  
Vol 79 (4) ◽  
pp. 370-376 ◽  
Author(s):  
Catherine Morlay ◽  
Yolande Mouginot ◽  
Monique Cromer ◽  
Olivier Vittori
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Acrylic Acid ◽  
Metal Ion ◽  
Conditional Stability ◽  
Binding Properties ◽  
Complex Species ◽  
Complexing Capacity ◽  
Dilute Aqueous Solution ◽  
Poly Acrylic Acid

The possible removal of copper(II), nickel(II), or lead(II) by an insoluble crosslinked poly(acrylic acid) was investigated in dilute aqueous solution. The binding properties of the polymer were examined at pH = 6.0 or 4.0 with an ionic strength of the medium µ = 0.1 or 1.0 M (NaNO3) using differential pulse polarography as an investigation means. The highest complexing capacity of the polyacid was obtained with lead(II) at pH = 6.0 with µ = 0.1 M, 4.8 mmol Pb(II)/g polymer. The conditional stability constants of the complex species formed were determined using the method proposed by Ruzic assuming that only the 1:1 complex species was formed; for lead(II) at pH = 6.0 and µ = 0.1 M, log K' = 5.3 ± 0.2. It appeared that the binding properties of the polymer increased, depending on the metal ion, in the following order: Ni(II) < Cu(II) < Pb(II). The complexing capacity and log K' values decreased with the pH or with an increase of the ionic strength. These results were in agreement with the conclusions of our previous studies of the hydrosoluble linear analogues. Finally, with the insoluble polymer, the log K' values were comparable to those previously obtained with the linear analogue whereas the complexing capacity values expressed in mmol g-1 were slightly lower.Key words: insoluble crosslinked poly(acrylic acid), copper(II), nickel(II), and lead(II) complexation.

Inerte Amminkomplexe als mehrwertige Kationsäuren in wäßriger Lösung / Inert Ammine Complexes as Multivalent Cationic Acids in Aqueous Solution

1980 ◽  
Vol 35 (9) ◽  
pp. 1096-1103 ◽  
Author(s):  
Matthias Kretschmer ◽  
Lutwin Labouvie ◽  
Karl-W. Quirin ◽  
Helmut Wiehn ◽  
Ludwig Heck
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Spectrophotometric Method ◽  
Complex Cation ◽  
Aqua Ligand ◽  
Second Step ◽  
Acidity Constants ◽  
Ammine Complexes ◽  
Temperature Variations ◽  
Enthalpy Changes

Acidity constants of ammine complexes of tetravalent platinum in aqueous solutions have been determined by a spectrophotometric method at very low ionic strengths and extrapolated to zero ionic strength. Temperature variations of pK-values (25 °C and 50 °C) yield thermodynamic parameters for two successive deprotonation steps of hexaammineplatinum(IV), pentaamminechloroplatinum(IV), and tris(ethylenediamine)pla- tinum(IV) complexes and for the deprotonation of pentaammineaquacobalt(III) ion.The enthalpy changes for the first and second steps are similar and range from 50 to 75 kJ/mole while for the aqua ligand of Co(III) 33 kJ/mole are found. The very large dif­ference in the entropy changes (about 70 to 80 J/K mole for the first step and -10 to + 20 J/K mole for the second step) is interpreted by a model of solvation change. The primary hydration sphere of strongly oriented and immobilized water dipoles around the highly charged complex cation is transformed to a hydrogen-bonded solvation sheath when the electric field of the complex is weakened upon release of the first proton.

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