THE ELECTRODE PROCESSES OF COPPER IN CYANATE, THIOCYANATE, SELENOCYANATE AND THIOUREA SOLUTIONS AT MERCURY AND COPPER AMALGAM ELECTRODES .1. THIOCYANATE AND THIOUREA SOLUTIONS

The electroreduction of thiocyanate complexes of Cu(II) and Cu(I) ions has been studied by polarography, voltammetry and large scale electrolysis. The chemical reaction of Cu(II) and SCN- is abruptly accelerated at about 2x10(-3) M of Cu(II) what is demonstrated by an unexpected decrease in the polarographic limiting current. The mechanism of this reaction is discussed. The electroreduction of SCN- ion docs not occur during electrolysis of thiocyanate complexes of Cu(II) and Cu(I) ions, unlike the Ni(II), Co(II), Fe(II) and Pd(II) ions. The S2- ion formed during the electroreduction of the Cu(II) ion in thiourea solution results from the electrolysis of formamidine disulphide (FDS). FDS is formed in the reaction of the Cu(II) ion with thiourea.