Determination by ion exchange of the complexation of europium by a stibine, an arsine, and perchlorate in anhydrous aprotic organic solvents

Abstract

It has been shown for the first time that a lanthanide (Eu³⁺) can be complexed by a stibine or a neutral arsine. In benzonitrile (PhCN) as the solvent the predominant complexes were (1)[Eu(Ph₃Sb)_z]³⁺ with triphenylstibine at a concentration of 0.003 mol dm^–3, (2)[Eu(Ph₃As)_y(ClO₄]²⁺ with triphenylarsine at 0.07 mol dm^–3, and (3)[Eu(Ph₃As)_x(ClO₄)₂]⁺ with Ph₃As at 0.003 mol dm^–3. In pure PhCN, neutral and/or negative complexes of Eu^{3 +} with ClO₄^– were found, but in pure dimethyl sulphoxide no complexation was detected. All complexes were determined by an ion-exchange technique employing the macroreticular resin Amberlyst 15.