Knowledge Bank

We have studied the x-ray photoelectron spectra arising from the valence region of molecular ions containing transition elements. We have included cyanides, halides and oxyanions of 3d, 4d and 5d transition elements in our studies. The spectra we obtain are not completely resolved but much of interest can be deduced from the positions and intensities of the features we have observed. We find that, in the cyanide complexes, the $t2g$ levels are more heavily localized on the metal than one might have expected. In the oxyanions there is little evidence for pi bonding in any species. All the oxyanions have studied show extensive participation by the metal in sigma bonding. The sigma bond strength is greater in the compounds of the upper series. The chloride complexes of the 4d and 5d elements show partially resolved features due to the non-bonding levels (C13p), the bonding levels and the antibonding levels.