Quantitative Equilibrium Studies on Binary and Ternary Complexes of 2-Aminobenzohydroxamic Acid With Inner Transition Metal Ions in Presence of Other Chelating Agents

P. Narender, D. Sudarshan Reddy, D. P. Madhava Reddy and *B. Satyanarayana

Bio-Inorganic Division, Department of Chemistry, College of Chemical Technology Osmania University, Hyderabad- 500 007 (India)  

The equilibrium studies on the formation of 1:1 and 1:2 binary M-ABH, M-(ABH)2 and ternary [M-ABH-A] chelate [where M=LaIII, PrIII, NdIII, SmIII, EuIII, and UO2II; ABH = 2-Amino benzohydroxamic acid; A = Iminodiacetic acid (IMDA), Hydroxyethyliminodiacetic acid (HIMDA), Nitrilotriaceticacid (NTA)] have been determined pH metrically in 10% (v/v) aqueous methanol medium at 30°C and I = 0.1 M KNO3. The ligand ABH coordinates as a secondary ligand in presence of IMDA, HIMDA and NTA with all the inner transition metal ions. The order of formation constants of binary as well as ternary chelates is found to be : LaIII < PrIII < NdIII < SmIII < EuIII < UO2II. Complex formation equilibria elucidated with the aid of specification curves.

Binary; ternary complexes; 2-Amino benzohydroxamic acid