Prof. Dr. Fritz Scholz and Dipl.-Chem. Aleš Dostal
The first report of the formal potentials of a series of solid metal hexacyanometalates (M+)nM′[M″ (CN)6] is given (M+ = Li+, K+, Na+, Rb+, Cs+; M′ = Ag, Al, Cd, Co, Cr, Cu, Fe, Ga, In, Mn, Ni, Pb; M″ = Cr, Fe, Mn). A linear correlation exists between the ionic potential Φ = z/reff of the nitrogen-bonded M′ ions and the formal potentials of the hexacyanometalate ions. This results from increased π back bonding when the acid–base interaction between the nitrogen atom of the cyanide ions and the M′ ions is stronger.