The extraction of PD(II) by tri-isobutylphosphine sulphide, TIBPS (Cyanex 47 1x), in toluene from aqueous chloride solutions (containing small amounts of thiocyanate) has been investigated. The extraction is enhanced by the presence of thiocyanate, owing to formation of mixed-ligand Pd(II)-Cl--SCN--TIBPS complexes. Analysis of the metal distribution suggests the formation of PdCl(SCN)·TIBPS, PdCl(SCN)·2TIBPS, Pd(SCN)2·TIBPS and Pd(SCN)2·2TIBPS in the organic phase. The equilibrium constants are logK111 =9.56, logK112 =12.70, logK121 =14.73 and logK122 =17.17, respectively. The ultraviolet absorption spectra of the organic phase support the hypothesis of formation of mixed-ligand complexes. © 1991.
|Publication status||Published - 1 Jan 1991|