Formation constants of the complexes of 2-hydroxy-1-napthaldoxime with some trivalent metal ions and UO22+

Potentiometric studies have been carried out on metal complexes of UO22+, Y3+, Pr3+, Gd3+, Dy3+ and Nd3+ with 2-hydroxy-1-naphthaldoxime. The proton association constant of the reagent and the formation constants of its metal complexes have been determined by Bjerrum's method at 250 +- 0.1. The departure from the electrostatic bond between metal and donor atoms of the reagent has been attributed to the size of the hydrated metal ions of rare earths. (author)