Correlations with energy level diagrams

In its salts and most of its compounds the C-N distance of cyanide is about 1.16 A which correlates well with the existence of a C N triple bond. A partial orbital energy level diagram for this ion is presented in Fig. 1 which illustrates that the highest filled orbital has az symmetry. 

Figure 10.65. The microwave spectrum of 13CH in its lowest rotational level, observed by Steimle, Woodward and Brown [179]. This spectrum may be correlated with the energy level diagram shown in figure 10.64.

Molecular orbital energy level diagrams which allow the assignment of these transitions have been developed by Gray et al. for M(CO) 58>194>. Fig. 2 shows the diagram for Cr(CO)e (after 58)). The correlation with the observed transitions (in CH3CN) is given in Table 1. 

There has been a vast quantity of ESR work in the field of cupric complexes with organic bases. Much of this work is on poorly characterized species and the parameters obtained are usually incomplete and of little value. The series of complexes [Cu(NHs) (H20)e ] + yield (657) a trend in g and A values which could with interest be related to the optical work of Jorgensen et al. (56). Spin densities on the protons of the hexaamine have been determined from NMR Knight (Contact) shifts (699). Shupack has correlated the g tensors of [Cu(NH3)8] + and [Cu(NH3)4] + with the molecular orbital energy level diagram (620). 

Fig. 7. An energy-level diagram for the APS two-step model, describing the different excitation channels [(a), (b)] and decay channels for SXAPS [(c), (d)] and AEAPS [(e), (f)] schematically. In the excitation step a 3d electron is excited near the Fermi energy, Ep, by an incident electron with energy p. Only transitions with at least one electron being excited to the 4f level are considered here. Due to correlation effects the energy of the 4f level depends on the number of 4f electrons. For the decay step a distinction...

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