Chemi-ionization

Not to be confused with chemical ionization.

Chemi-ionization is the formation of an ion through the reaction of a gas phase atom or molecule with an atom or molecule in an excited state.

Reactions

Chemi-ionization can be represented by

$G^* + M \to M^{+\bullet} + e^- + G$

where G is the excited state species (indicated by the superscripted asterisk), and M is the species that is ionized by the loss of an electron to form the radical cation (indicated by the superscripted "plus-dot").

See also

• Penning ionization
• Associative ionization
• Charge-exchange ionization