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Stepwise formation of some metal chelates with N-arylhydroxamic acids—A potentiometric study

1971; Elsevier BV; Volume: 33; Issue: 1 Linguagem: Inglês

10.1016/s0022-0728(71)80221-8

2590-2954

J.P. Shukla, S. G. Tandon,

Chemical Thermodynamics and Molecular Structure

Thermodynamic stepwise formation constants of the chelates of UO22+, Cu2+, Ni2+, Zn2+, and Mn2+ with five closely related N-arylhydroxamic acids have been determined at 35±0.1°C using the Bjerrum-Calvin pH titration technique as applied by Van Uitert and Haas to dioxane-water mixtures. A 50% v/v aqueous dioxane is employed as the solvent medium owing to the poor water-solubility of the ligands and their metal complexes. The stabilities of the complexes mostly follow the order of basicity of the ligands. Other factors affecting chelate stability of the metal ions are discussed.