Determination of Stability Constants of 2-Hydroxy-1-Naphthalidene-Thiosemicarbazone Complexes with Be2+, Y3+, Pr3+, Nd3+, Dy3+, Gd3+ and UO22+

Department of Chemistry, Ramnarain Ruia College, Bombay-400 019

Manuscript received 14 February 1980, revised 20 January 1981, accepted 13 April 1981

Potentiometric studies have been carried out on metal complexes of Be²⁺, Y³⁺, Pr³⁺, Nd³⁺. Dy³⁺, Gd³⁺ and \(UO_2^{2+}\) with 2-hydroxy-1-naphthalidene-thiosemicarbazone. The proton-ligand dissociation constants (pK₁ and pK₂) of the reagent and the formation constants of its metal complexes have been determined by Bjerrum's method at 25^o ± 0.1^o and at an ionic strength 0.1 M In 75 : 25 percent (v/v) dioxan-water medium. The validity of Born's relation was examined by studying the plot of Z²/r vs log k values of rare earth complexes of the ligand.