Experimental and theoretical studies of the gas-phase reactions of O(${}^1$D) with H${}_2$O and D${}_2$O at low temperature

Abstract

Here we report the results of an experimental and theoretical study of the gas-phase reactions between O(${}^1$D) and H${}_2$O and O(${}^1$D) and D${}_2$O at room temperature and below. On the experimental side, the kinetics of these reactions have been investigated over the 50-127 K range using a continuous flow Laval nozzle apparatus, coupled with pulsed laser photolysis and pulsed laser induced fluorescence for the production and detection of O(${}^1$D) atoms respectively. Experiments were also performed at 296 K in the absence of a Laval nozzle. On the theoretical side, the existing full-dimensional ground X${}^1$A potential energy surface for the H${}_2$O${}_2$ system involved in this process has been reinvestigated and enhanced to provide a better description of the barrierless H-atom abstraction pathway. Based on this enhanced potential energy surface, quasiclassical trajectory calculations and ring polymer molecular dynamics simulations have been performed to obtain low temperature rate constants. The measured and calculated rate constants display similar behaviour above 100 K, showing little or no variation as a function of temperature. Below 100 K, the experimental rate constants increase dramatically, in contrast to the essentially temperature independent theoretical values. The possible origins of the divergence between experiment and theory at low temperatures are discussed.

References in corpus (8)

• Chemical Reaction Rates from Ring Polymer Molecular Dynamics: Theory and Practical Applications
• The C(3P) + NH3 reaction in interstellar chemistry: II. Low temperature rate constants and modeling of NH, NH2 and NH3 abundances in dense interstellar clouds
• The C(3P) + NH3 reaction in interstellar chemistry: I. Investigation of the product formation channels
• An experimental and theoretical investigation of the C(1D) + D2 reaction
• Unusual Low Temperature Reactivity of Water. The CH + H2O Reaction as a Source of Interstellar Formaldehyde?
• Temperature Dependent Product Yields for the Spin Forbidden Singlet Channel of the C(3P) + C2H2 Reaction
• Isotopic Separation of Helium through Nanoporous Graphene Membranes: A Ring Polymer Molecular Dynamics Study
• The low temperature D${}^{+}$ + H${}_2$ $\to$ HD + H${}^{+}$ reaction rate coefficient: a ring polymer molecular dynamics and quasi-classical trajectory study

Cited by in corpus (2)

• A Kinetic Study of the Gas-Phase O( 1 D) + CH3OH and O( 1 D) + CH3CN Reactions. Low Temperature Rate Constants and Atomic Hydrogen Product Yields
• Kinetic study of the CN + C2H6 hydrogen abstraction reaction based on an analytical potential energy surface