skip to main content

SciTech ConnectSciTech Connect

Title: Interaction of O{sup −} and H{sub 2} at low temperatures

Reactive collisions between O{sup −} and H{sub 2} have been studied experimentally at temperatures ranging from 10 K to 300 K using a cryogenic radiofrequency 22-pole ion trap. The rate coefficients for associative detachment, leading to H{sub 2}O + e{sup −}, increase with decreasing temperature and reach a flat maximum of 1.8 × 10{sup −9} cm{sup 3} s{sup −1} at temperatures between 20 K and 80 K. There, the overall reaction probability is in good agreement with a capture model indicating efficient non-adiabatic couplings between the entrance potential energy surfaces. Classical trajectory calculations on newly calculated potential energy surfaces as well as the topology of the conical intersection seam leading to the neutral surface corroborate this. The formation of OH{sup −} + H via hydrogen transfer, although occurring with a probability of a few percent only (about 5 × 10{sup −11} cm{sup 3} s{sup −1} at temperatures 10–300 K), indicates that there are reaction paths, where electron detachment is avoided.
Authors:
; ; ; ; ; ;  [1] ; ;  [2]
  1. Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00 (Czech Republic)
  2. Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00 (Czech Republic)
Publication Date:
OSTI Identifier:
22415456
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; CAPTURE; ELECTRON DETACHMENT; HYDROGEN; HYDROGEN TRANSFER; ION-MOLECULE COLLISIONS; OXYGEN IONS; POTENTIAL ENERGY; PROBABILITY; RADIOWAVE RADIATION; SURFACES; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0013-0065 K; TEMPERATURE RANGE 0065-0273 K; TRAPS; WATER