A Polarographic Study of the Copper-formamidine Disulfide Dihydrochloride System in Aqueous Solution

Abstract

Many studies have been made on the solid complexes of thiourea with various metal ions. However, much less information is available on these systems in solutions. The copper(II)-thiourea system is especially intriguing. | Copper(II) complexes of thiourea (tu) are reported to be unstable (1) (2). Only one reference makes any attempt to describe the reaction products (3). They report that formamidine disulfide dihydrochloride (FDS*2HC1) and a copper(I) complex of thiourea result when cupric chloride is added to thiourea. However, it is felt by this author that inadequate proof is presented for the presence of FDS*2HC1 as a reaction product. In addition, if FDS*2HC1 is formed, it is surprising that complexation was not observed between the FDS*2HC1 and the copper present in the solution. If FDS*2HC1 can form complexes with copper, it would appear that cupric ions might be stabilized in the presence of thiourea.