A comparative analysis of the electrophilicity of organic molecules between the computed IPs and EAs and the HOMO and LUMO energies

The electrophilicity index, ω, of a series of substituted ethylenes used in some relevant organic reactions has been evaluated from the ionization potential (IP) and the electron affinity (EA) computed by vertical ionization at the B3LYP/aug-cc-PVTZ level. The corresponding electrophilicity values are well correlated with those obtained from the HOMO and LUMO energies of the neutral molecules. The good linear correlation found between ω(I,A) and ω(H,L)LBS, and between ω(H,L)LBS and ω(H,L)SBS allows to confirm the use of the easily available B3LYP/6-31G∗ HOMO and LUMO energies to obtain reasonable values of the global electrophilicity index of organic molecules.