Antibonding energy

Immediately, therefore, we have one insight into the spectrochemical series by noting that both bonding and antibonding energy shifts of eg and e orbitals are... 

The orbital interactions determine how many and which mos will have low (bonding), intermediate (non-bonding), and higher (antibonding) energies, with all energies viewed relative to those of the constituent atomic orbitals. The general patterns that are observed in most compounds can be summarized as follows ... 

Fig. 9. A schematic representation of the interaction between the ns orbital (SHOMO) of the s-m-butadiene unit in 37 and the rr-orbital (HOMO) of the dienophilic component of 38, assuming the formation of syn-adducts [82, 84, 85]. The four center/four electron destabilization of exo-face approach (exo-2) is characterized by a larger net antibonding energy [87] than endo-face approach (endo-2) which is consequently favored. The orbitals show the effects of the disrotatory tilts which they are believed to experience. Note that in the terms endo-2 and exo-2, the 2 refers to the diene unit. Subsequently, the terms endo-1 and exo-1 are also employed where the 1 refers to the ene portions of the dienophilic unit...

According to the model, the antibonding energy of the n/-orbital of the metal in the complex is proportional to the square of its overlap integral with the ligand orbitals. The antibonding energy, E may be written as... 

The first (bonding) and the last (antibonding) energy levels of the linear polyene chain are reported with respect to Nin Table 3.1 in units of (3. In the last column of the table is the difference in energy between two successive levels. The asymptotic approach of x towards 2 and of % towards -2 is apparent from the numbers given in the table, as well as is the decreasing distance between two successive levels, which tends to zero for N —> oo. 

In addition to the degeneracies in eigenvalues, there are two important differences. For even values of N the energies of the highest and lowest molecular orbitals are independent of N, Secondly, if the valence electron band is half filled, in the open chain for no value of W, an antibonding energy level with eigenvalues a < <... 

---