Energies, Auger calculation

Molecular orbital/energy band calculations have been performed for a range of iron(II) sulfides and there is interest in the band-like valence-electron states in FeSj and also in their bulk and surface properties typified by studies using Auger spectroscopy " and X-ray absorption. The extensive work in this area published during the period 1960-1969 is contained in an excellent review by Ward. Unfortunately, discussion about the fascinating tricyclic iron(III) polysulfide anion [Fc2S 2] and its reactions with, for example, activated alkynes " are outside of the scope of this section. 

Figure 4.6. Photoemission and the Auger process. Left An incident X-ray photon is absorbed and a photoelectron emitted. Measurement of its kinetic energy allows one to calculate the binding energy of the photoelectron. The atom becomes an unstable ion with a hole in one of the core levels. Right The excited ion relaxes by filling the core hole...

The significance of the values calculated for the effective polarizability was first established with physical data, among them relaxation energies derived from a combination of X-ray photoelectron and Auger spectroscopy, as well as N-ls ESCA data53, 54). From our point of view, however, the most important applications of effective polarizability are to be found in correlating chemical reactivity data. Thus, the proton affinity (PA) of 49 unsubstituted alkylamines comprising primary, secondary and tertiary amines of a variety of skeletal types correlate directly with effective polarizability values (Fig. 22). 

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