Charge transfer phenomena in some inorganic complexes. Part III. Ultraviolet spectra of transition-metal derivatives of iron group cyanide complex anions

Abstract

The spectra of a range of transition-metal hexacyanoferrate(II), hexacyanoferrate(III), and hexacyanocobaltate(III) compounds are described, and discussed in terms of Robin's model of Prussian Blue. It is shown that the charge-transfer in the hexacyanoferrate(III) and hexacyanocobaltate(III) compounds is from cation metal to anion metal, while the charge-transfer in the hexacyanoferrate(II) compounds is in the opposite sense. When there is more than one charge-transfer band, the separations observed are related to the different possible spectroscopic terms the transfer of one electron could produce. The relationship of the charge-tranfer energies to the activation energies of electronic conduction in the hexacyanocobaltate compounds is discussed.