Direct-current induced oxidation–reduction reactions in some partially oxidised cyano- and oxalato-platinate crystals containing platinum–platinum chains
Abstract
The application of d.c. fields of greater than 200 V cm–1 to K1·74Pt(CN)4,1·8H2O and K1·64Pt(C2O4)2,pH2O (where p indicates an unknown number of water molecules) induces and oxidation–reduction reaction which commences at the anode and spreads through the crystal towards the cathode. The products of the reactions appear to be K1·74H0·26Pt(CN)4,xH2O and K1·64H0·36Pt(C2O4)2,gH2O (where g indicates an unknown number of water molecules). Mg0·82Pt(C2O4)2,5·3H2O does not undergo this reaction at the anode up to 3000 V cm–1. K1·64Pt(C2O4)2,pH2O at 50 V cm–1 and K1·74Pt(CN)4, 1·8H2O at 500 V cm–1 exhibit a colour change at the cathode. Evidence suggests that this is due to partial replacement of K+ by H+ ions.