Electrostatic and nonelectrostatic, conventional and unitary thermodynamic quantities of reaction. I. Metal–ligand reactions in aqueous solvent

1986 ◽  
Vol 64 (4) ◽  
pp. 780-784 ◽  
Author(s):  
Roberto Aruga

A calculation method of the electrostatic and nonelectrostatic parts of thermodynamic quantities of reaction, previously proposed and applied to complex-formation reactions of aminic and carboxylic ligands, is applied, in the present work, to association reactions of several other ligands. In particular, to check its reliability, this method is applied to ΔG0, ΔH0, and ΔS0 data of literature for the formation of metal–anion pairs and for associations of metals with ligands containing pyridine nitrogen, ethereal oxygen, or thioethereal sulfur. Experimental data referring only to aqueous solutions are considered. The results obtained by this method are in agreement, in most cases, with those expected for the reactions examined. Therefore, it seems reliable and useful for a more significant interpretation of conventional thermodynamic parameters.

1993 ◽  
Vol 58 (6) ◽  
pp. 1269-1278 ◽  
Author(s):  
Roberto Herrero ◽  
Isabel Brandariz ◽  
Sarah Fiol ◽  
Manuel Sastre de Vicente

On the basis of the ionic strength dependence of the equilibrium constant (pK*) of thriethanolamine (TEA) and glycine, the ionic interaction parameters of the species involved in the equilibria TEAH+ ↔ TEA + H+ (for TEA), AH2+ ↔ AH + H+ and AH ↔ A- + H+ (for glycine) in aqueous solutions of KCl and KNO3, respectively, were determined using the Pitzer equations. Values of pK* were expressed on both the molarity and the molality scale at various temperatures and values of thermodynamic quantities ∆G0, ∆H0 and ∆S0 ascertained, for TEA.


2015 ◽  
Vol 12 (6) ◽  
pp. 3996-4008
Author(s):  
Hussein A Mohamed ◽  
Magdy A Wassel ◽  
Rabie S Farg ◽  
Hassan A Shehata ◽  
Aamal M Anwar

The object of this study is to assess the removal of Fe(III) ions from aqueous solutions onto modified chitosan. The effect of various parameters has been investigated by the following batch adsorption technique. The various variables studied include initial concentration of the adsorbate, agitation time, adsorbent dosage, kinetics, influence of temperature. The experimental data was fit well to the Freundlich isotherm. Thermodynamic parameters such as ΔH, ΔS and ΔG were calculated, indicating that the adsorption was spontaneous and endothermic nature.


2016 ◽  
Vol 12 (2) ◽  
pp. 3996-4008
Author(s):  
Hussein A Mohamed ◽  
Magdy A Wassel ◽  
Rabie S Farg ◽  
Hassan A Shehata ◽  
Aamal M Anwar

The object of this study is to assess the removal of Fe(III) ions from aqueous solutions onto modified chitosan. The effect of various parameters has been investigated by the following batch adsorption technique. The various variables studied include initial concentration of the adsorbate, agitation time, adsorbent dosage, kinetics, influence of temperature. The experimental data was fit well to the Freundlich isotherm. Thermodynamic parameters such as ΔH, ΔS and ΔG were calculated, indicating that the adsorption was spontaneous and endothermic nature.


1991 ◽  
Vol 69 (9) ◽  
pp. 1388-1393 ◽  
Author(s):  
Yasuki Yoshimura

The solubilities of tris(2,4-pentanedionato)cobalt(III) and tris(3,5-heptanedionato)cobalt(III) in water, heptane, and 1,2-ethanediol were determined over the temperature range 5–50 °C and from these data the thermodynamic quantities of solution at 25 °C were estimated. The free energy [Formula: see text], enthalpy [Formula: see text], and entropy [Formula: see text] of transfer of these chelates from heptane to some solvents were calculated from the corresponding thermodynamic quantities of solution. When [Formula: see text] and [Formula: see text] were separately plotted against [Formula: see text], the data of transfer from heptane to water deviated markedly from a correlation obtained for the data of transfer to the solvents other than water. This finding indicates that these chelates are subject to hydrophobic hydration in their aqueous solutions. The solubility of tris(glycinato)cobalt(III) in water was also determined over the temperature range 5–60 °C and its temperature dependence of the solubility is compared with that for the cobalt(III) chelates of the β-diketones. Key words: tris cobalt(III) chelates of β-diketones and glycine, temperature dependence of solubility, thermodynamic parameters of solution, thermodynamic parameters of transfer, hydrophobic hydration.


1989 ◽  
Vol 54 (6) ◽  
pp. 1475-1481 ◽  
Author(s):  
N. Papadopoulos ◽  
G. Ritzoulis

Molar conductivities at the limit of zero concentration have been evaluated for NaI and NaBPh4 in acetone and in isopropanol at 10, 15, 20, 25, and 30 °C. The experimental data have been analysed by means of the Lee-Wheaton equation. The thermodynamic parameters of the non-coulombic interaction have been evaluated.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Khémesse Kital ◽  
Moumouny Traoré ◽  
Diégane Sarr ◽  
Moussa Mbaye ◽  
Mame Diabou Gaye Seye ◽  
...  

Abstract The aim of this work is to determine the thermodynamic parameters and the kinetics of complex formation between orthophthalaldehyde (OPA) and agmatine (AGM) in an alkaline medium (pH 13). Firstly, the association constant (Ka) between orthophthalaldehyde and agmatine was determined at different temperatures (between 298 K and 338 K) with a step size of 10 K. Secondly, the thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°),and Gibbs energy (∆G) were calculated, where a positive value of ΔH° (+45.50 kJ/mol) was found, which shows that the reaction is endothermic. In addition, the low value of ΔS°(+0.24 kJ/mol) indicates a slight increase in the disorder in the reaction medium. Furthermore, the negative values of ΔG between −35.62 kJ/mol and −26.02 kJ/mol show that the complex formation process is spontaneous. Finally, the parameters of the kinetics of the reaction between OPA and AGM were determined as follows: when the initial concentration of AGM (5 × 10−6 M) is equal to that of the OPA, the results show that the reaction follows an overall 1.5 order kinetics with an initial rate of 5.1 × 10−7Mmin−1 and a half-life of 8.12 min. The partial order found in relation to the AGM is 0.8. This work shows that the excess of OPA accelerates the formation reaction of the complex.


Author(s):  
Ivan Saenko ◽  
O. Fabrichnaya

AbstractThermodynamic parameters were assessed for the MgO–FeOx system and combined with already available descriptions of ZrO2-FeOx and ZrO2-MgO systems to calculate preliminary phase diagrams for planning experimental investigations. Samples of selected compositions were heat treated at 1523, 1673 and 1873 K and characterized using x-ray and scanning electron microscopy combined with energy dispersive x-ray spectroscopy (SEM/EDX). Experiments indicated extension of cubic ZrO2 solid solution into the ternary system at 1873 K (75 mol.% ZrO2, 10 mol.% FeOx and 15 mol.% MgO) and limited solubility of 4 mol.% ZrO2 in spinel phase. Based on the obtained results thermodynamic parameters of C-ZrO2 and spinel phase were optimized.


Data in Brief ◽  
2021 ◽  
Vol 35 ◽  
pp. 106869
Author(s):  
Behzad Rahimi ◽  
Nayereh Rezaie-Rahimi ◽  
Negar Jafari ◽  
Ali Abdolahnejad ◽  
Afshin Ebrahimi

2010 ◽  
Vol 7 (1) ◽  
pp. 227-233

This is about synthesizing new complex combinations of Cu(II), Ni(II),Co(II), Zn(II) with aroylhydrazone ligand isonicotinoylhydrazone-2-aldehydefluorene (INHAF) made by condensation of isonicotinoylhydrazine with 2-aldehydefluorene. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility values, thermal analysis and for the Cu(II) complex the ESR spectrum has been registered. For all complexes the biological activity against theStaphylo-coccus aureus, Escherichia coli, Klebssiella pneumoniaebacteria has been investigated. The experimental data sustain stoichiometry of 1:2 (metal/ligand) for the Cu(II), Ni(II), Zn(II) complexes and of 1:1 for the complex with Co(II). The electronic spectra and the magnetic moments suggest octahedral stereochemistry at the complexes with Cu(II), Ni(II) and the tetrahedral geometry for the Co(II) complex. The INHAF ligand is coordinated bidentate by the O=C amide oxygen and the azomethine nitrogen in the complexes of Cu(II), Ni(II), Co(II) and monodentate by the azomethine nitrogen in the complex of Zn(II).


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