Studies on thermal stabilities of coordination compounds by gas chromatography: XVIII. Activation and hydrogenation of coordinated CN −

Various metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Sn, La) ferrocyanides and ferricyanides may be considered as a multibond activation model of bimetal coordination, since CN − acts as a typical ambident ligand bonded at the two ends with two metal ions. In accordance with hydrogenation reactions of CN − taking place during thermal decomposition in hydrogen, the activation effect of bimetal coordination and the mechanism of hydrogenation reaction of CN − are discussed from the viewpoint of the crystal structure and the electron structure of the complexes. The activation degree of CN − bonded with various metal ions has been investigated. It was found that the temperature at which the triple bond of CN − breaks with top speed to evolve NH 3 correlates closely with the standard electrode potential, and d electron configuration of the metal ions.