MOLAR CONDUCTOMETRIC AND STEPWISE POTENTIOMETRIC STUDIES ON CHROMIUM(III)-2,2'-DIPYRIDYL-SALICYLALDOXIME-BENZAMIDE, MANGANESE(II)-2,2'-DIPYRIDYL-SALICYLALDOXIME-BENZAMIDE, COPPER(II)-2,2'-DIPYRIDYL-SALICYLALDOXIME-BENZAMIDE, AND SILVER(I)-2,2'-DIPYRIDYL-SALICYLALDOXIME-BENZAMIDE COMPLEXES

Molar conductivity titrations and conductometric measurements as well as pH-metric studies were done on Cr(III), Mn(II), Cu(II), and Ag(I) with 2,2'-dipyridyl (Dipy), salicylaldoxime(SD) and benzamide (BAM) at 350 and 45 degrees C. Conductivity and potentiometry studies indicated the formation of 1:1, 1:2 and 1:3 Cr(III)-, Mn(II): and Cu(II)- and 1:1 and 1:2 Ag(I)-Dipy or BAM, 1:1 and 1:2 Cu(II)- and Ag(I)-Dipy-SD, Dipy-BAM and SD-BAM and 1:1:1:1 Cr(III)-, Mn(II)-, Cu(II)-, and Ag(I)-Dipy-SD-BAM complexes. Complexation takes place through two coordinate bonds between the metal ions and the two nitrogen atoms of Dipy, two covalent bonds between the metal ions and the phenolic OH and oximic OH groups of salicyialdoxime, and coordinate and covalent bonds between the metal ions and the benzoyl CO and amide NH groups of BAM. Proton-ligand and metal ligand(s)) conditional stability constants at 35 and 45 degrees C were estimated. Thermodynamic parameters (Delta degrees G, Delta H, Delta S) at 35 and 45 degrees C of binary, ternary and quaternary complexes were evaluated.