Energetics, structure and photodissociation dynamics of the cluster Arter dot N sup + sub 2

Journal Article · Sun Jul 15 00:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459179· OSTI ID:6687870

Kim, H; Bowers, M T ^[1]

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1. Department of Chemistry, University of California, Santa Barbara, California 93106 (USA)

A mass selected ion beam of ArN{sup +}{sub 2} clusters is brought to a spatial focus and crossed with the polarized output of an argon ion laser. Photofragment ions are mass and energy analyzed using an electrostatic analyzer and detected using single ion counting methods. Photoproducts observed over the photon energy range of 2.1 to 3.5 eV are Ar{sup +}/N{sub 2} and N{sup +}{sub 2}/Ar with the former favored by about a factor of 3. Analysis of the data indicate the upper state is purely repulsive leading to strongly translationally and vibrationally excited products. The absolute cross section has an onset at about 600 nm and smoothly increases to 357 nm. In order to reasonably interpret the data it is suggested the higher energy Ar{sup +}({sup 2}{ital P}{sub 3/2})/N{sub 2} asymptote diabatically correlates to the ground state of ArN{sup +}{sub 2} and the lower energy N{sup +}{sub 2}({ital X} {sup 2}{Sigma})/Ar asymptote diabatically correlates to the repulsive state accessed by the photon. Detailed dynamics in the region where the curves cross are responsible for the observed product distribution. Application of an impulsive model indicates the ground state of ArN{sup +}{sub 2} is linear. Finally, equilibrium measurements of the reaction (N{sub 2}){sup +}{sub 2}+Ar{leftrightarrow}ArN{sup +}{sub 2}+N{sub 2} indicate {Delta}{ital H}{sup 0}{sub 0}={minus}1.0{plus minus}0.3 kcal/mol and {Delta}{ital S}{sup 0}=1.5{plus minus}0.5 cal k{sup {minus}1} mol{sup {minus}1} in agreement with the result of Teng and Conway which had been disputed in the literature.

• OSTI ID: 6687870
• Journal Information: Journal of Chemical Physics; (USA), Vol. 93:2; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ARGON COMPLEXES
PHOTOLYSIS
NITROGEN COMPLEXES
DISSOCIATION
EQUILIBRIUM
EXCITATION
ION BEAMS
LASER RADIATION
MOLECULAR BEAMS
MOLECULAR STRUCTURE
BEAMS
CHEMICAL REACTIONS
COMPLEXES
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
PHOTOCHEMICAL REACTIONS
RADIATIONS
640301* - Atomic
Molecular & Chemical Physics- Beams & their Reactions
400500 - Photochemistry