Investigation of some complex cyanides in solid solution

Abstract

This work describes the investigation of the complex cyanide ions Fe(CN)6 3-, Fe(CN)6 4-, and Fe(CN)5NO2- incorporated in alkali (and alkaline earth) halides. Details are given of the preparation and Spectrophotometric Analysis of the solid solutions. Infra-red Absorption data from the cyanide asymmetric stretch region 2000-2200 cm-1 indicates distortion of the complex ions in the host lattices. A theoretical model of the impurity ion in face-centered cubic host lattices is used to predict the number of cyanide stretch fundamentals as a result of induced asymmetry and compared with experiment. Ionic conductance measurements at elevated temperatures give evidence for the existence of permanent positive ion vacancies postulated in the model. Observed frequency shifts of ?? CN fundamentals may be correlated with long and short range interaction energies in the host crystal.