Collision energy dependence of the cross sections for the dissociative excitation reactions: Rg(3P0,2) +NH3→Rg+NH(A 3Π, c 1Π)+H2 (Rg=Ar, Kr)
- 1 May 1986
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 84 (9) , 4930-4937
- https://doi.org/10.1063/1.449980
Abstract
The integral cross sections for the title reactions were determined for the relative collision energies between 0.3 and 1.4 eV by applying arc‐heating metastable rare gas beams to a crossed molecular beam–time‐of‐flight (TOF) energy selection technique, in which product fluorescence intensities from both NH(A 3Π–X 3Σ−) and NH(c 1Π–a 1Δ) bands were monitored. With Ar(3P0,2 ) excitation, the relative branching fractions of nascent NH(A 3Π) and NH(c 1Π) formation were found to be invariant with the collision energy within the experimental error. With Kr(3P0,2) excitation, however, no apparent NH(c 1Π–a 1Δ) emission was observed, only emission from NH(A 3Π) was observed. The absolute cross section for formation of these nascent NH radicals was also determined. Collision energy dependence of the cross section for the reaction Ar (3P0,2) +NH3→Ar(1S0)+NH(A 3Π,c 1Π)+H2 was found to be negative, whereas that for the reaction Kr(3P0,2 )+NH3→Kr(1S0)+NH(A 3Π)+H2 showed positive dependence in the collision energy range studied. Possible mechanisms for the formation of NH(A 3Π,c 1Π) from Rg(3P0,2)+NH3 are discussed.Keywords
This publication has 21 references indexed in Scilit:
- Photodissociation of NH3 at 106–200 nmThe Journal of Chemical Physics, 1983
- Vacuum ultraviolet photodissociation of ammoniaJournal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 1982
- Velocity Analysis of Supersonic Molecular Beams of NH3, C2H2, CO2 and SF6Japanese Journal of Applied Physics, 1981
- TOF analysis of an optically pumped metastable neon beamThe Journal of Chemical Physics, 1981
- Franck-Condon analysis of predissociations in the lower valence states of the NH radicalJournal of Quantitative Spectroscopy and Radiative Transfer, 1979
- Selective removal of either metastable species from a mixed 3P0,2 rare-gas metastable beamReview of Scientific Instruments, 1975
- Excited mercury–ammonia system. Part 1.—Kinetics of the attachment of NH3and ND3to Hg(63P0), and measurement of the emission ratesJournal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics, 1974
- An evaluation of molecular constants and transition probabilities for the NH free radicalJournal of Quantitative Spectroscopy and Radiative Transfer, 1973
- Frank-Condon factors and absolute oscillator strengths for NH, SiH, S2 and SOJournal of Quantitative Spectroscopy and Radiative Transfer, 1971
- Reactions of Ar, Kr, and Xe Metastables with Simple NH-Containing CompoundsThe Journal of Chemical Physics, 1970