Molecule vs. Ionization

In the discharge of organic molecules, the ionization is not an accurate picture of the step that creates the luminous gas phase. First of all, the ionization energy 

the ionization of an organic molecule is far more complex than the ionization of Ar, and one can easily estimate the extent of the dissociation reactions by comparing the energies necessary for the dissociation reactions and the ionization energy of a molecule. The following examples provide some indication of the 

Gas Dissociation energy Metastable energy Ionization energy 

Ionization is the essential step in sustaining luminous gas phase but is not necessarily the primary step in initiating LCVD reactions. The scission of bonds occurs with a far greater frequency than the formation of ions. It was estimated that the concentration of neutral species in low-pressure plasma is usually five to six orders of magnitude higher than that of ions and electrons [8]. In other words, the scission of bonds does not occur as the consequence of the ionization of molecules but rather as the primary step to create luminous gas phase. 

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