Ionization Potentials of Polyatomic Molecules

Abstract

THE recent development of our knowledge of the electronic structures of molecules makes it possible to specify with reasonable certainty the particular electron with which a definite molecular ionization potential is to be associated. In an organic molecule the variation of an ionization potential with, for example, alkyl or halogen substitution reflects the change in negative charge density in that part of the molecule in which the electron is located. The existence of resonance in a molecule also considerably affects the ionization potentials of the resonating electrons. It is clear, too, that ionization potentials are intimately bound up with chemical activity, dipole moments, refractivities, combination radii, electronegativities, etc.