Potentiometric Studies on Mixed Ligand Complexes of Gallium(III), Taking NTA as Primary Ligand and Some Aliphatic Carboxylic Acids as Secondary Ligands

Department of Chemistry, Nagpur University, Nagpur-10

Manuscript received 20 January 1979, revised 8 June 1979, accepted 19 May 1980

Potentiometric studies on some mixed ligand complexes of Ga(III) are reported. Nitrilotriacetic acid (NTA) was used as primary ligand whereas, malic acid, maleic acid, malonic acid, succinic acid, oxalic acid and itaconic acid were employed as secondary ligands. \(Log_{MAL}^{MA}\) was evaluated, using modified form of Irving and Rossotti's method. The stability constant values were found to be in the order, malonic acid ≈ maleic acid > malic acid > oxalic acid > succinic acid> itaconic acid. Thermodynamic parameters. e.g. ΔG°, Δ H° and ΔS° have also been evaluated. Results obtained are correlated on the basis of steric and structural characteristics of the chelates.