Acidity and basicity investigation for novel derivative of salen and stabilities of their complexes with metal cations : research report

Abstract

Salen derivative, 4 was synthesized and studied for determination of its protonation constants by potentiometric titration. The protonation constants at 25 degree Celsius in 0.1 and 0.5 M KNO[subscript 3] are log K[subscript 1]=10.06, log K[subscript 2]=7.96, log K[subscript 3] = 7.12, log K[subscript 4]= 3.28 and log K[subscript 1]=10.48, log K[subscript 2]=7.99, log K[subscript 3] = 4.71, log K[subscript 4] =2.77, respectively. Complexation for the 4 complexes with Ni(II), Cu(II) and Zn(II) in 0.01 M Bu[subscript 4]NCF[subscript 3]SO[subscript 3] in MeOH were determined by UV-VIS spectrometric titration. The Stability constants, in terms of log[beta] [subscript 11], the 4 complexes with Ni(II), Cu(II) and Zn(II) are 3.80, 4.28 and 4.37, respectively.