HOMO/LUMO energies

Dissociation Energy, HOMO-LUMO Cap, Triplet-Single Gap, and Bond Length for the Triplet and Singlet States of the Studied Molecules... 

E energy (HOMO - LUMO) The AE reflects chemical reactivity. It was recently reported that chemicals with AE >9 eV (as calculated by AMI) are much less likely to be acutely toxic to aquatic species [32]... 

Table 15 TDDFT excitation energies, HOMO-LUMO gaps (Ah l), and the negative of HOMO energies (-shomo) of oiigomer 16 (in units of eV)...

Species Total n-binding energy HOMO-LUMO gap TRE... 

The transition energy ( HOMO-LUMO gap ) was not calculated in the model systems in Section 3, but, as a rule of thumb, for sterically unhindered systems ho) often correlates inversely with both the conjugation length and the magnitude of the transition dipole (Fabian and Hartmann, 1980) as predicted... 

What about the photochemical Diels-Alder reaction The observation that this reaction is most uncommon leads us to the immediate suspicion that there is something wrong with it. Usually, the absorption of a photon will promote an electron from the HOMO to the LUMO. In this case, the lower energy HOMO-LUMO gap is that in the diene partner. Absorption of light creates a new photochemical HOMO for the diene, 3, and now the HOMO-LUMO interaction with the dienophile partner involves one antibonding overlap. Both new bonds cannot be formed at the same time (Rg. 20.22). So this photochemical Diels-Alder reaction is said to be forbidden by orbital symmetry. ... 

Fig. 10.6 Graphical representation of orbital energies HOMO-LUMO for the six isomers a, P, y, a, P, y when X = As, [AS2W18O62] As an example, we have also depicted 3D orbitals for isomer y (Dsj) HOMO (orbital of symmetry A2 , mainly composed of p-oxygen orbitals delocalized over oxygen bridge, belt and terminal atoms) and LUMO (orbital of Au symmetry, mainly composed of d-metal orbitals delocalized over the metal belt atoms)...

---