Gas phase ion-molecule reactions, spectroscopy and dynamics

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5220631

Rinden, E

The chemical reactivity of nitric oxide anion (NO{sup {minus}}) with a variety of organic neurals at ambient and in argon bath gas has been probed using the flowing afterglow technique. The reactions fall into four main classes: electron transfer, dissociative electron transfer and/or displacement, collisional detachment and clustering. Electron transfer can occur when the neutral reactant possesses a positive electron affinity greater than the electron affinity of NO{center dot}, but does not always do so. Bimolecular substitution at sulfur is shown to occur with dimethyl disulfide, but for other substrates, distinguishing between displacement and dissociative electron transfer is not possible. Collisional detachment is the exclusive reaction channel observed for a few of the molecules examined, and occurs to some extent with many of the neutrals tested. Cluster ion formation between NO{sup {minus}} and a number of the reactant neutrals which possess permanent dipole moments is observed. The collected observations are discussed in the general theory of ion-molecule reactions. Cross sections for vibrational relaxation in small ionic systems (Li{sup +}-H{sub 2},Li{sup +}-D{sub 2}, ArH{sup +}-Ar and ArD{sup +}-Ar) have been calculated numerically using the j{sub z}-conserving coupled states approximation (CSA), and contrasted with cross sections calculated by methods which exclude the effects of attractive forces and/or rotation. Both attractive forces and rotations are found to be extremely important contributors to relaxation in ions; in the Li{sup +}-H{sub 2}/D{sub 2} systems these effects are separable whereas in ArH{sup +}/D{sup +}-Ar they are not. Attractive forces substantially enhance the cross sections at all collision energies and are responsible for the general collisional energy dependence of the cross sections. Molecular rotation is found to enhance cross sections most strongly at low collision energies in each system.

• Research Organization: Brown Univ., Providence, RI (United States)
• OSTI ID: 5220631
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
NITRIC OXIDE
ION-MOLECULE COLLISIONS
AMBIENT TEMPERATURE
ANIONS
CROSS SECTIONS
DISSOCIATION
ELECTRON DETACHMENT
ELECTRON TRANSFER
ION BEAMS
ION PAIRS
ION SOURCES
MOLECULAR IONS
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
RELAXATION
BEAMS
CHALCOGENIDES
CHARGED PARTICLES
COLLISIONS
ION COLLISIONS
IONS
MOLECULE COLLISIONS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
640304* - Atomic
Molecular & Chemical Physics- Collision Phenomena