Thermochemical study of complexation and solvation in β-alanine-Cu(NO3)2-water-ethanol system: 1. Enthalpy characteristics of complexing copper(II) Ion with β-alanine

Thermochemistry of solvation and complexation in the Cu(NO3)2-water-ethanol-L-α-alanine system at 298.15 K

“…It should be noted that the conditions and proce dure of a thermochemical experiment were maximally adjusted to those for working with β alanine [3,5]. The heats of mixing of aqueous solutions of sodium alaninate (NaAla) and Cu(NO 3 ) 2 were measured using an isoperibolic solution calorimeter with a cell volume of 50 ml; its design was described in [7].…”

“…This work continues the studies [1][2][3][4] devoted to the solvation of salts of d elements in mixed aqueousorganic solvents and their effect on the thermodynam ics of complexation with bioactive ligands. It has been shown in [5,6] that the alteration of the chemical composition of the medium (alteration of concentra tion of a nonaqueous component) in which complex ation takes place, has a considerable effect on the sta bility of the resulting complexes and in some cases facilitates the formation of new chemical forms of complex species that cannot be formed or are poorly stable in aqueous media.…”

“…The effect of composition of a binary aqueousorganic solvent on the enthalpies of formation of β alaninate copper(II) complex [CuAla] + and the enthalpy parameters of this process were studied ear lier [3][4][5]. We revealed in those studies that an increase in ethanol concentration in the aqueous solution results in a significant gain in exothermicity of com plexation and enhancea the stability of the β alaninate complex.…”

“…It has been shown in [5,6] that the alteration of the chemical composition of the medium (alteration of concentra tion of a nonaqueous component) in which complex ation takes place, has a considerable effect on the sta bility of the resulting complexes and in some cases facilitates the formation of new chemical forms of complex species that cannot be formed or are poorly stable in aqueous media. It has been demonstrated in the same studies that changes in solvation surrounding of the electron donating groups of the ligand are the most significant factors for the stability of a complex during the formation of amine complexes of d metals in nonaqueous solvents [6].…”

“…It has been shown in [5,6] that the alteration of the chemical composition of the medium (alteration of concentra tion of a nonaqueous component) in which complex ation takes place, has a considerable effect on the sta bility of the resulting complexes and in some cases facilitates the formation of new chemical forms of complex species that cannot be formed or are poorly stable in aqueous media. It has been demonstrated in the same studies that changes in solvation surrounding of the electron donating groups of the ligand are the most significant factors for the stability of a complex during the formation of amine complexes of d metals in nonaqueous solvents [6].The effect of composition of a binary aqueousorganic solvent on the enthalpies of formation of β alaninate copper(II) complex [CuAla] + and the enthalpy parameters of this process were studied ear lier [3][4][5]. We revealed in those studies that an increase in ethanol concentration in the aqueous solution results in a significant gain in exothermicity of com plexation and enhancea the stability of the β alaninate complex.…”