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

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 Eu3+ 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. (author)