A potentiometric investigation of complex formation between some metal ions and biologically active quinazoline-4-3(H)-one Schiff’s base
作者:K. Shivakumar、S. Shashidhar、M. B. Halli
DOI:10.1134/s0036024407100251
日期:2007.10
The proton dissociation constant of the ligand and the stability of the complexes of Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Cu(II), Ba(II), Mg(II), Mn(II), Th(IV), and UO2(II) ions with 2-phenyl-3-(2'hydroxy-5'-benzylidine)-quinazoline-4-(3H)-one [PBQ] were determined potentiometrically at 30 +/- 0.1 degrees C and ionic strengths of 0.025, 0.05, 0.10, 0.15 and 0.20 M NaNO3 in a 60: 40 (v/v) ethanol-water medium. The proton-ligand and metal-ligand stability constants of the complexes were determined pH metrically by the Calvin-Bjerrum titration technique. The order of stability constants obeys the Irving-Rossotti rule. The negative values of. G suggest that the reactions are spontaneous.