NEW SULFUR-CONTAINING REAGENTS AS CARRIERS FOR THE SEPARATION OF PALLADIUM BY SOLID SUPPORTED LIQUID MEMBRANES

N2-substituted N1-phenylbenzamidines and N'-disubstituted N-benzoyl th iourea derivatives, which contain donor S, N and O atoms, have been st udied as carriers for the facilitated transport of Pd(II). These reage nts have been shown to be effective in the solvent extraction of palla dium. Thiocyanate ions or thiourea have been employed as stripping age nts. The use of these reagents as carriers in liquid membranes was car ried out by developing both bulk and supported liquid membranes. The p resence of NaSCN in the feed solution at appropriate concentration res ults in an increase in the rate and mass transfer of palladium. N-benz oyl thiourea derivatives have been shown to be the most effective for Pd(II) transport and several compounds with enhanced lipophilic charac teristics were prepared. A comparison of the results obtained reveals a significant influence of lipophilicity (side chain substituent) on t he permeability of Pd(II).