Thermal analysis of some cyano compounds

The thermal behaviour of the title compounds in static air has been investigated by conventional thermal analysis (TG and DSC) and infrared spectroscopy of the solid residues at various temperatures. The following points are demonstrated:

1. the presence ofan alkali metal cation (e.g. Na(I) or K(I)) appears to be a necessary, but not sufficient condition for the intermediate formation of cyanate in the oxidation of Fe(CN) ₆ ^n? (n=3 or 4);
2. a multivalent cation favours a hydrolytic mechanism, with preferential evolution of HCN rather than H₂O;
3. the thermally induced reduction of Cu(II) to Cu(I) occurs simultaneously with the linkage isomerism of CN^?, with the resultant formation of Cu(I)-CN^? complexes.