Effect of Water-Acetone Solvent on the Stability of Copper(II)and Nickel(II)Nicotinamide Complexes

摘要

Complexation of nicotinamide with Cu2+ and Ni2+ ions in a water-acetone solvent is studied.The equilibrium constants of these reactions are determined by potentiometric titration at the ionic strength 0.25 mol/l NaClO4 and 298 K in the interval of mixed solvent compositions from 0 to 0.45 molar fraction of acetone.The Cu(II)complex with nicotinamide becomes stronger in a water-acetone mixture.The dependence of the stability constant of the Ni(II)complex with nicotinamide on the concentration of the organic component in the solution has extremum with a minimum at 0.1-0.2 molar fraction of acetone.The effect of a change in the solvate state of the reactants on the stability of the complexes is discussed.