A paper chromatographic investigation of the thiourea complexes of copper(I) silver(I) and gold(I)

Abstract

Several thiourea complexes of formula M 1Tu x A (M I = Cu(I), Ag(I) and A = ClO 4, BF 4, CF 3COO, CH 3COO or HCOO; or M 1 = Au(I) and A = ClO 4, BF 4, CF 3COO, Cl or Br; Tu = thiourea) were prepared; the maximum Tu:M ratio is 3:1 for Cu(I) and Ag(I) and 2:1 for Au(I). The same maximum of 3:1 is observed on high frequency titration of the Ag(I) salts with thiourea in methyl cellosolve. Some of these complexes, undecomposed and in compact spots, may be eluted on chromatographic paper with a mixture of ketones and an aqueous solution of the corresponding sodium salt, or with a mixture of alcohols and an aqueous solution of the corresponding free acid. The Tu:M ratio is 5:2 for Cu(I) perchlorate and fluoroborate in ketones, while it is always 2:1 for the other complexes of Cu(I), Ag(I) and Au(I), irrespective of the anion, the solvent and the amount of aqueous solution in the mixture. The composition of the eluted complexes was determined by a radiochemical method after exchange with 35S-labelled thiourea. The R F values of the eluted complexes depend on the anion, the solvent and the amount of aqueous solutions in the mixture.