A multichannel harpoon model for reactive quenching of Xe 5 p sup 5 np by Cl sub 2

• Published in: The Journal of chemical physics 1990-01, Vol.92:1
• Main Authors: Bruce, M.R., Layne, W.B., Keto, J.W.
• Format: Article
• Language: English
• Subjects: 400201 - Chemical & Physicochemical Properties; 426002 - Engineering- Lasers & Masers- (1990-); AMPLITUDES; ATOM COLLISIONS; ATOM-MOLECULE COLLISIONS; CHEMICAL REACTION KINETICS; CHLORIDES; CHLORINE; CHLORINE COMPOUNDS; COLLISIONS; CROSS SECTIONS; DE-EXCITATION; ELEMENTS; ENERGY LEVELS; ENERGY TRANSFER; ENERGY-LEVEL TRANSITIONS; ENGINEERING; EXCIMER LASERS; EXCITATION; EXCITED STATES; FLUIDS; GAS LASERS; GASES; HALIDES; HALOGEN COMPOUNDS; HALOGENS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; KINETICS; LANDAU-ZENER FORMULA; LASERS; MATHEMATICAL MODELS; MOLECULE COLLISIONS; NONMETALS; QUENCHING; RADIATIONLESS DECAY; RARE GAS COMPOUNDS; RARE GASES; REACTION KINETICS; TEMPERATURE DEPENDENCE; TRANSITION AMPLITUDES; VIBRATIONAL STATES; XENON; XENON CHLORIDES; XENON COMPOUNDS
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.458445

A harpoon reaction model employing multiple crossings based on the formalism of Bauer {ital et} {ital al}. (J. Chem. Phys. {bold 51}, 4173 (1969)) and Gislason and Sachs (J. Chem. Phys. {bold 62}, 2678 (1975)) is developed to explain the large cross sections ({sigma}{similar to}330--975 A{sup 2}) measured for the reaction Xe*(5{ital p}{sup 5}{ital np},{ital np}{prime}, {ital n}=6,7)+Cl{sub 2}. The model calculates the Landau--Zener transition probability for each intermediate ionic crossing with the covalent surface. The transition matrix elements are represented as a product of the electronic interaction (modeled by the empirical result of Olson {ital et} {ital al}. (Appl. Opt. {bold 10}, (1971))) and a Franck--Condon factor for the Cl{sub 2}{r arrow}Cl{sup {minus}}{sub 2} transition. The model predicts near unit probability for a transition to the ionic surface for impact parameters less than 20 Bohr. Once transfer occurs, the pair is captured by dissociation of Cl{sup {minus}}{sub 2} to form XeCl*. The large temperature dependence observed qualitatively in the experiments is explained by the increased cross section for vibrationally excited Cl{sub 2}. A simple model for orbiting collisions is used to estimate the effect of termolecular collisions.