Completion of polydentate Schiff bases derived from 2-aminophenol and 2-aminophenylmethanol with Cu(II) ion

Abstract

The stability constant of the Cu(II) complexes with 2-{[2(hydroxyphenyl)-methylene]-amino}-phenol and -phenylmethanol were determined using a potentiometric method at two different temperatures (15 and 30+/-0.1 degrees C) and three ionic strengths (0.01, 0.05 and 0.25 M NaClO4) in 3/5 (v/v) 2-propanol/water mixture. Plots of thermodynamic stability constants at zero ionic strength (log K-t) versus T-1 gave linear curves and Delta S-0 and Delta H-0 were also calculated from these plots. It has been compared to the stabilities of the chelate ring systems that both ligands formed with Cu(II) ion.