Stepwise Stability Constants of Gallium(lll) Complexes with Picolinic Acid and 8-Hydroxyquinoline and its Derivatives

Department of Chemistry, Nagpur University, Nagpur Manuscript received 5 August 1974; revised 10 December 1974: accepted 13 January 1975 The potentiometric study of Gallium(III) complexes with Picolinic acid (PA), 8-Hydroxy­quinoliue-5-sulfonic acid (OSA), 7-iodo-8-Hydroxyquinoline-5-sulfonic acid (IOSA) in aqueous medium and with 8-Hydroxyquinoline (OX) in 50% v/v aqueous-dioxan media have been carried out at an ionic strength µ = 0.2M. The Proton-Ligand stability constants and stepwise formation constants of the complexes have been determined by the Calvin-Bjerrum pH titration technique as used by Irving-Rossotti. Log K values have been computed by alternative methods. The trend in stability constant values of Gallium(III) complexes have been found to be OX > OSA IOSA > PA