Akademik Veri Yönetim Sistemi
JOURNAL OF SOLUTION CHEMISTRY, cilt.33, sa.11, ss.1467-1479, 2004 (SCI-Expanded)
The formation and protonation constants of 17 Schiff bases-derived 2-hydroxyaniline with some substituted benzaldehydes, and the stability constants of Cu(II) complexes of these Schiff bases, have been determined potentiometrically in 20, 40, and 60% dioxane - water media. The data from the potentiometric titrations were evaluated with the BEST computer program. For all Schiff bases studied, it was observed that the log K-OH values related to the protonation equilibria of the phenolic oxygen are increased, and the log K-NH values related to the protonation equilibria of the azomethine nitrogen are decreased, as the dioxane content is increased. The variation of these constants is discussed on the basis of specific solute - solvent interactions and structural changes of Schiff bases from water to the dioxane - water media. Also, titrimetric-pH investigation of substituted benzilidene-2-hydroxyaniline systems has revealed the formation of stable mono-Schiff base complexes with the metal ion Cu( II).