V. A. Sharnin

The influence of the composition of an aqueous-acetone solvent on the thermodynamic characteristics of complex formation of 18-crown-6 ether with glycine

The heat effects of solution of 18-crown-6 ether were determined calorimetrically over a wide range of water-acetone solvent compositions (298.15 K). The influence of the composition of water-acetone solvents on the enthalpies of complex formation between 18-crown-6 and glycine and solvation of chemical equilibrium participants was studied. It was shown that the factor determining changes in the enthalpy of the reaction was changes in the solvation state of the crown ether.

The influence of solvation on the formation of Ag+ complexes with 18-crown-6 ether in water-dimethyl sulfoxide solvents

The Gibbs energies of transfer of 18-crown-6 ether from water into water-dimethyl sulfoxide (DMSO) solvents (χDMSO = 0.0–0.97 mole fractions) at 298.15 K were determined by the interphase distribution method. Changes in the composition of the aqueous-organic solvent did not cause noticeable changes in the stability of 18-crown-6 ether solvato complexes. Reagent solvation contributions to shifts of complex formation equilibrium between silver(I) and 18-crown-6 ether when water was replaced with dimethyl sulfoxide were analyzed.

Thermodynamic characteristics of the formation reactions of nickel(II) glycinates and the solvation of reagents in aqueous ethanol solutions

Enthalpies of complexation reactions between nickel(II) and the glycinate ion in mixtures of water with ethanol containing up to 0.5 mole fraction ethanol were obtained by the calorimetric titration method at 298 K. With increasing ethanol concentration exothermicity of complexation was found to increase slightly for the first coordination step. The results obtained were analyzed from the standpoint of solvation approach based on thermodynamic characteristics of all reagents. It was shown that the main cause of the increase in the exothermicity of complexation reactions is the weakening of ligand solvation with increasing ethanol concentration.

The influence of water-acetone solvents on the acid-base properties of glycylglycine

The protonation and dissociation constants of glycylglycine in variable-composition water-acetone solvents were determined potentiometrically at the ionic strength of solutions 0.1 M (NaClO4) and 298 K. Reagent solvation contributions to shifts of acid-base equilibria are analyzed.

Influence of the composition of acetonitrile-dimethyl sulfoxide solvent on the thermodynamics of silver(I) complexation with piperidine

The influence of the composition of the acetonitrile-dimethyl sulfoxide solvent on the main thermodynamic characteristics (ΔG°, ΔH°, ΔS°) of the complexation between silver(I) and piperidine was studied by the calorimetric and potentiometric methods. Analysis of the obtained experimental material was carried out using the solvation approach based on the thermodynamic solvation characteristics of the reactants.

Thermodynamic parameters of the complexation of the silver(I) ion with 2,2'-dipyridyl in methanol-dimethylformamide binary solvents

The heat effects of formation of one-and two-ligand complexes of silver(I) with 2,2′-dipyridyl at 298.15 K were measured by the calorimetric method over the entire range of compositions of the methanol-dimethylformamide solvent, and the entropy and Gibbs energy changes for these reactions were calculated. The influence of the composition of the mixed solvent on thermodynamic characteristics of these processes is discussed. The contributions from the enthalpies of solvation of the reactants to the heat effects of the complexation reactions were considered.