ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Oscillographic polarography of hexathiocyanatochromate(III) anion

E. Fischerová and O. Fischer

Department of Theoretical and Physical Chemistry, Faculty of Natural Sciences of the University, Brno

Abstract: The hexathiochromic complex (I) showed 3 cathodic spikes with the streaming electrode. The spike at -0.8 v. vs. the satd. calomel electrode corresponded to a reversible 1-electron reduction of I; the spikes at -1.6 v. to a 2-electron irreversible reduction of Cr(II) complex to metallic Cr. In dild. electrolytes, between both spikes, a 3rd one appeared corresponding to a redn. of another form of the depolarizer which was formed in the vicinity of the electrode. The transformation of the depolarizer in the neighborhood of the electrode before the reduction was rapid in cyanide solns. The anomalous shape of the 2nd spike in very dil. neutral solns., the drop below the 0 line of the oscillogram and formation of loops, were assocd. with desorption of thio complexes from the Hg surface. The high neg. charge (-3) of I causes its repulsion from the electrode surface, which was shown by the dependence of the depth of the 1st 2 spikes on concn. and on the kind of cation of the supporting electrolyte.

Full paper in Portable Document Format: 1411-12a743.pdf (in Czech)

Chemical Papers 14 (11-12) 743–751 (1960)