SPECTRA OF THE ONE AND TWO ELECTRON (OR HOLE) TRANSITION METAL CYANIDE COMPLEXES

Abstract

The transition metal cyanides have for a number of years eluded a systematic classification of their spectra. This circumstance arose quite simply because elementary estimates of their expected energy spectrum by means of an electrostatic crystal field model gave meaningless results. In recent years, however, the success attained by the molecular orbital based crystal field theory, the so-called ligand field theory, in the accurate prediction of the optical and magnetic properties of the first transition series complexes, has raised the hope that a similar model might also explain the spectra of the enigmatic cyanides, and perhaps eventually even those of the mystifying carbonyls, nitrosyls, etc. It is this latter hope which has instituted our attempt to correlate the spectra of the one and two electron (or hole) transition metal cyanides. The spectra thus far obtained will be displayed, and a theoretical explanation of the main spectral features will be given. A few points which require further theoretical investigation will be noted, and some suggestions for future progress will be made.