Template:Ion/molecule reactions

Transcluded in ASMS 1981 and ASMS 1984

Ion/neutral reaction

A process wherein a charged species interacts with a neutral reactant to produce either chemically different species or changes in the internal energy of one or both of the reactants. (NB. The term ion/neutral reaction is not ideal, simply because the word neutral is not a noun. However, any alternatives such as ion/neutral-species are so clumsy as to seem unlikely to be generally accepted).

Ion/molecule reaction

An ion/neutral reaction in which the neutral species is a molecule.

Charge inversion reaction

An ion/neutral reaction wherein the charge on the reactant ion is reversed in sign.

Charge transfer reaction

An ion/neutral reaction wherein the total charge on the reactant ion is transferred initially to the reactant neutral species so that the reactant ion becomes a neutral entity.

Partial charge transfer reaction

An ionn/neutral species reaction wherein the chargenon a multiply-charged reactant ion is reduced.

Charge stripping reaction

An ion/neutral reaction wherein the charge on the reactant ion is made more positive.

Charge permutation reaction

This is a general term to describe an ion/neutral reaction wherein there is a change in the magnitude and/or sign of the charges on the reactants.

(Note: Considering some of the possible reactions of ions M²⁺, M⁺ and M^- with a neutral species N these would be categorised on the basis of the above definitions as follows:

M²⁺ + N → M⁺ + N (Partial charge transfer)

M⁺ + N → M²⁺ + N + e^- (Charge stripping)

M^- + N → M⁺ + N + 2e^- (Charge stripping and charge inversion)

All are ion/neutral reactions and also charge permutation reactions].

Collision-induced dissociation

An ion/neutral process wherein the (fast) projectile ion is dissociated as a result of interaction with a target neutral species. This is brought about by conversion of part of the translational energy of the ion to internal energy in the ion during the collision.

Collisional activation

An ion/neutral process wherein excitation of a (fast) projectile ion is brought about by the same mechanism as in collision-induced dissociation. (The ion may decompose subsequently)n.

Collisional excitation

An ion/neutral process wherein there is an increase in the (slow) reactant ion's internal energy at the expense of the translational energy of either (or both) of the reacting species. The scattering angle may be large.

(Note: It is recommended that all three of the above terms should be retained).

Elastic scattering

An ion/neutral interaction wherein the direction of motion of the ion is changed, but there is no change in the total translational energy or internal energyof the collision partners.

Inelastic scattering

An ion/neutral interaction wherein the direction of motion of the ion is changed, and the total translational energy of the collision partners is reduced.

Elastic collision

A collision resulting in elastic scattering.

Inelastic collision

A collision resulting in inelastic scattering.

Superelastic collision

A collision in which the translational energy of the fast-moving collision partner is increased.

Ionizing collision

An ion/neutral reaction in which an electron or electrons are strippedfrom the ion and/or the neutral species in the collision. 'Generally, this term has come to be used to describe collisions cif fast moving ions with a neutral species in which the neutral species is ionized with no change in the number of charges carried by the ion. Care should be taken when this term is used to emphasize if charge stripping of the ion has taken place.

Association reaction (associative combination)

The reaction of a (slow moving) ion with a neutral species wherein the reactants combine to form a single ionized species.

Ion/neutral exchange reaction

In this reaction an association reaction is accompanied by the subsequent or simultaneous liberation of a different neutral species as product.

Translational spectroscopy

A technique to investigate the distribution of the velocity of product ions from ion/neutral reactions.

Ion energy loss spectra

Spectra that show the loss of translational energy of ions involved in ion/neutral reactions.

Impact parameter

The distance of closest approach of two particles if they had continued in their original direction of motion at their original speeds.

Interaction distance

The furthest distance of approach of two particles at which it is discernible that they will not pass at the impact parameter.

Charge exchange reaction

This term is synonymous with Charge Transfer Reaction.

Partial charge exchange reaction

This term is synonymous with partial charge transfer reaction.