Electronic Excitation and Ionization Energies

Correlations with Electronic Excitation and Ionization Energies 

In general, however, magnetically allowed transitions are electric dipole forbidden and give weak bands in the electronic spectrum. These may be obscured by stronger allowed bands such as 7t - ti in aromatic systems, that are magnetically inactive since the charge displacement is linear. In these, 5/X correlations are usually unsuccessful since the magnetically active and a- n (and u- u ) excitations are sub- 

In saturated systems, the relevant n- a or r a energies are larger and the forbidden a a bands difficult to identify. Correlations may, however, be observed with the ionization energies of lone pair homos (variations in the lumos being smaller) as in the S/Ij plots for 0 in aliphatic alcohols and ethers.  

Transition metal complexes may yield good 5IX(d—d) relationships, which are 

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QM/EFPl scheme was used for investigating a variety of chemical processes in aqueous environment, including chemical reactions, amino acid neutral/zwitterion equilibrium, solvent effects on properties of a solute such as changes in dipole moment and shifts in vibrational spectrum, and solvatochromic shifts of electronic levels [36, 56, 59-60, 71-79]. Applications of a general QM/EFP scheme were limited so far to studies of electronic excitations and ionization energies in various solvents [56-58]. Extensions of QM/EFP to biological systems have been also developed [80-85]. 

Birks, J.B. and Slifkin, M.A. 1961. Tr-Electronic excitation and ionization energies of condensed ring aromatic hydrocarbons. Nature 191 761-764. 

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