The Formal Potentials of Solid Metal Hexacyanometalates

Abstract

The first report of the formal potentials of a series of solid metal hexacyanometalates (M + ) n M′[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 /r eff 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.