Complexation of Vanadium(IV) with Hydroxamate Chelators and Their Stability Relation with pH

Hydroxamic acids, RCONHOH, form highly stable complexes with vanadium(IV) in 1:1, 1:2 and 1:3 molar ratios. The stability constants of the complexes were determined through spectrophotometric and potentiometric methods at various pH and found to be comparable. Acetohydroxamate, benzohydroxamate and salicylhydroxamate were selected for the study. Using the spectrophotometric method, graphical calculations were applied to confirm the results. Potentiometric method associated with computer calculation program BEST was also applied to check the reproducibility of the results.