scholarly journals The Thermodynamics of Copper (II) and Nickel (II)- Diamine Complex Formation in Aqueous Solution

2021 ◽  
Author(s):  
◽  
Harry Kipton James Powell
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Thermodynamic Functions ◽  
Electrode System ◽  
Glass Electrode ◽  
Complex Ions ◽  
Degree Of Hydration ◽  
Enthalpy Changes ◽  
Delta G ◽  
The Stability

<p>This work describes the accurate measurement of the thermodynamic functions Delta G degree and Delta H degree for the step-wise coordination equilibria between each of the ions H+, Ni2+, Cu2+, and, a series of C1-substituted 1,2-diaminoethanes in aqueous solution. The study Involved. (a) The construction of a sensitive constant temperature environment calorimeter for measuring the enthalpy changes in the complex-formation reactions, (b) The rigorous calibration of an electrode system, incorporating a glass electrode, for the direct potentiometric measurement of equilibrium hydrogen ion concentrations in the solutions containing complex ions. The thermodynamic functions Delta G degree and Delta H degree led to accurate Delta S degree values for the step-wise complex-formation reactions. The thesis considers the contribution of the entropy of ligation to the stability of complex ions. The molar entropies of the complex ions have been calculated and their values considered with respect to the coordination number and the possible structure, degree of hydration and steric properties of the ions.</p>

scholarly journals The Thermodynamics of Copper (II) and Nickel (II)- Diamine Complex Formation in Aqueous Solution

2021 ◽  
Author(s):  
◽  
Harry Kipton James Powell
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Thermodynamic Functions ◽  
Electrode System ◽  
Glass Electrode ◽  
Complex Ions ◽  
Degree Of Hydration ◽  
Enthalpy Changes ◽  
Delta G ◽  
The Stability

<p>This work describes the accurate measurement of the thermodynamic functions Delta G degree and Delta H degree for the step-wise coordination equilibria between each of the ions H+, Ni2+, Cu2+, and, a series of C1-substituted 1,2-diaminoethanes in aqueous solution. The study Involved. (a) The construction of a sensitive constant temperature environment calorimeter for measuring the enthalpy changes in the complex-formation reactions, (b) The rigorous calibration of an electrode system, incorporating a glass electrode, for the direct potentiometric measurement of equilibrium hydrogen ion concentrations in the solutions containing complex ions. The thermodynamic functions Delta G degree and Delta H degree led to accurate Delta S degree values for the step-wise complex-formation reactions. The thesis considers the contribution of the entropy of ligation to the stability of complex ions. The molar entropies of the complex ions have been calculated and their values considered with respect to the coordination number and the possible structure, degree of hydration and steric properties of the ions.</p>

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.

scholarly journals Modeling and Thermodynamic Values of Complex Equilibrium of Cobalt(II) with Diethylenetriaminepentaacetic Acid in Aqueous Solution

2021 ◽  
Author(s):  
Ghusoon Faidhi Hameed ◽  
Fawzi Yahya Waddai ◽  
Nahla Shakir Salman
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Complex Formation ◽  
Stability Constant ◽  
Wide Spectrum ◽  
Equilibrium Constants ◽  
Diethylenetriaminepentaacetic Acid ◽  
The Stability ◽  
Hoff Equation ◽  
Potentiometric Data

The paper reports the study of the complex formation of cobalt (II) with diethylenetriaminepentaacetic acid (DTPA, H5L) based on spectrophotometric (SF) and potentiometric data (pH). Complexes of different compositions were found, and equilibrium constants, as well as the stability constants of these complexes, were determined. Accumulation of complexes in proportion is calculated based on the acidity of the medium. The experimental data have been carried out by using mathematical models to assess the solution's possible existence with a wide spectrum of complex particles and to point out those which are quite sufficient to copy the experimental data. In addition, thermodynamic parameters (ΔG°, ΔH°, and ΔS°) for the studying complexes were calculated according to the values of stability constant (KST) at 25 °C obtained from the temperature dependence of stability constant by using van’t Hoff equation.

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.

Complex formation between sulfur dioxide and halide ions

1977 ◽  
Vol 55 (15) ◽  
pp. 2807-2812 ◽  
Author(s):  
Etela Milanova ◽  
Robert L. Benoit
Keyword(s):  
Sulfur Dioxide ◽  
Complex Formation ◽  
Enthalpy Of Solution ◽  
Halide Ions ◽  
Iodide Ions ◽  
Enthalpy Changes ◽  
Stability Order ◽  
The Difference ◽  
The Stability ◽  
Dipolar Aprotic Solvents

Complex formation between sulfur dioxide and iodide ions in acetonitrile (AN) has been studied by vapour pressure measurements. The enthalpy changes ΔH0 for 1:1 association reactions between SO2 and halide (X−) ions in AN and between SO2 and Cl− in dimethylsulfoxide (DMSO) have been determined at 25 °C by calorimetry. The ΔH0 values (kcal mol−1) are respectively −4.1 (Cl−), −3.4 (Br−), −3.0 (I−) in AN and −0.7 (Cl−) in DMSO. In contrast to previous literature data there is a linear relationship between these ΔH0 and reported ΔG0 values for the formation of the SO2X− complexes in AN. The difference between the ΔH0 values for SO2Cl− in the solvents AN and DMSO is accounted for by the more exothermic enthalpy of solution of SO2 in DMSO which is the more basic solvent, and by the expected minor difference in the enthalpies of transfer of Cl− and SO2Cl− from AN to DMSO, both dipolar aprotic solvents. Some of the problems connected with the stability order of the SO2X− complexes are discussed in relation to solvent effects and properties of X−.

scholarly journals Photochemical Reductive trans-Elimination from trans-Diacidotetracyanoplatinate(IV) Complexes

1978 ◽  
Vol 33 (11) ◽  
pp. 1352-1356 ◽  
Author(s):  
A. Vogler ◽  
A. Kern ◽  
B. Fußeder ◽  
J. Hüttermann
Keyword(s):  
Aqueous Solution ◽  
Potential Energy ◽  
Hydrogen Abstraction ◽  
Quantum Yields ◽  
Complex Ions ◽  
Energy Diagram ◽  
High Quantum ◽  
Potential Energy Diagram ◽  
The Stability ◽  
Recombination Reactions

AbstractUpon CT excitation the complex ions trans-[Pt(CN)4N3X]2- and trans-[Pt(CN)4X2]2- (X = Cl and Br) undergo a reductive trans-elimination with formation of [Pt(CN)4]2- and two ligand radicals in the photoprimary step. The formation of a Pt(III) intermediate is not observed. Due to the stability of [Pt(CN)4]2-, recombination reactions regenerating the starting complex are efficient if the ligand radicals are not scavenged. For the azide complexes the high quantum yields for the production of [Pt(CN)4]2- are explained by the instability of azide radicals. For trans-[Pt(CN)4X2]2-, the recombination is efficient in aqueous solution, while in ethanol the halogen atoms are scavenged by hydrogen abstraction. The sequence of steps following CT excitation can be explained by a potential energy diagram.

Komplexone, XLVII Die Thermodynamik der Komplexbildung von einigen ein- und zweiwertigen Metallionen mit Aethylendiamintetraacetat- und Uramildiacetat-Ion / Complexone, XLVII Thermodynamics of Complex Formation of Some Univalent and Bivalent Metal Ions with Ethylenediaminetetraacetate and Uramildiacetate Anions

1976 ◽  
Vol 31 (6) ◽  
pp. 786-789 ◽  
Author(s):  
G. Anderegg
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Thermodynamic Functions ◽  
Univalent Cations ◽  
Bivalent Metal ◽  
Calorimetric Measurements ◽  
Thermodynamics Of Complex Formation ◽  
Bivalent Metal Ions ◽  
The Stability ◽  
Comparison Data

The enthalpies of complex formation of EDTA and uramildiacetate (UDA) with univalent cations (H+, Li+, Na+, K+, Ag+ and Tl+) have been obtained by direct calorimetric measurements at ionic strength 0.1 (or 1) and 20°C. For comparison data for the formation of 1:1 UDA complexes with Mg2+, Ca2+, Ba2+ and Sr2+ have also been obtained. From these values and the stability constants the thermodynamic functions ΔG and ΔS are calculated. The results are compared with those of similar systems.

scholarly journals Thermodynamic and structural studies of complexes of manganese(II), cobalt( II), nickel(II) and copper(II) with aminofuropyridine carboxamide

2003 ◽  
Vol 68 (6) ◽  
pp. 463-470 ◽  
Author(s):  
El Abd
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Spectral Data ◽  
Stability Constants ◽  
Thermodynamic Functions ◽  
Structural Studies ◽  
The Stability

Complexes of Mn(II), Co(II), Ni(II) and Cu(II) with 2-aminofuro[3,2-b]pyridine- 3-carboxamide have been prepared. The stability constants of the formed complexes were determined at 20, 30, 40 and 50 ?C at a fixed ionic strength, I = 0.1 mol dm-3 (KCl). The values of the thermodynamic functions associated with complex formation were calculated and analyzed in terms of electrostatic and non-electrostatic components. The complexes were characterized with the help of chemical and spectral data.

REMOVAL OF HEAVY METAL Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II) IONS FROM AQUEOUS SOLUTION BY MENTHA PIPERITA EXTRACT

2020 ◽  
pp. 15-20
Author(s):  
Ersin Yucel ◽  
Mine Yucel
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
High Efficiency ◽  
Correlation Coefficients ◽  
Langmuir Model ◽  
Mentha Piperita ◽  
Freundlich Model ◽  
Biosorption Capacity ◽  
Peppermint Extract ◽  
The Stability

In this study, the usage of the peppermint (Mentha piperita) for extracting the metal ions [Mg (II), Cr (II), Ni (II), Cu (II), Zn (II), Cd (II), Pb (II)] that exist at water was investigated. In order to analyze the stability properties, Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherms were used at removing the metal ions and the highest correlation coefficients (R2) were obtained at Langmuir isotherm. Therefore, it is seen that the Langmuir model is more proper than the Freundlich model. However, it was found that the correlation coefficients of removing Ni and Cd is higher at Freundlich model than Langmuir and low at Dubinin-Radushkevich isotherm. It is established that the biosorption amount increase depends on the increase of biosorbent and it can be achieved high efficiency (95%) even with small amount (0.6 mg, peppermint extract) at lead ions. It is also determined that the peppermint extracted that is used at this study shows high biosorption capacity for metal ions and can be used for immobilization of metals from polluted areas.

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