Determination of Dissociation Constants of Some Azoderivatives of Acetylacetone (2,4-Pentanedione) and Stability Constants of Their Complexes

摘要

The dissociation constants in water-ethanol solution (3 : 7) were determined for 3-phenyIazo-2,4-pentanedione (R_1), 3-(4-acetylphenylazo)-2,4-pentanedione (R_2), 3-(4-iodophenylazo)-2,4-penlanedione (R_3), 3-(4-bromophenylazo)-2,4-pentadione (R_4), 3-(4-chlorophenylazo)-2,4-pentanedione (R_5), and 3-(4-nitrophe-nylazo)-2,4-pentanedione (R_6), as well as the stability constants of complexes of some metals with these reac-tants. A correlation was found between the induction constant of the functional group and the acidity of the synthesized reactants. The stability constants of the Fe~(3+), Cu~(2+), UO~(2+)_2, Ni~(2+), Ni~(2+), Co~(2+), Zn~(2+), Cd~(2+), Mn~(2+), Mg~(2+), and Ca~(2+) complexes with the acetylacetone derivatives studied change in the following series: