A1 Refereed original research article in a scientific journal
Tunneling chemical exchange reaction D plus HD -> D-2 + H in solid HD and D-2 at temperatures below 1 K
Authors: Sheludiakov S, Ahokas J, Jarvinen J, Zvezdov D, Lehtonen L, Vainio O, Vasiliev S, Lee DM, Khmelenko VV
Publisher: ROYAL SOC CHEMISTRY
Publication year: 2016
Journal: Physical Chemistry Chemical Physics
Journal name in source: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Journal acronym: PHYS CHEM CHEM PHYS
Volume: 18
Issue: 42
First page : 29600
Last page: 29606
Number of pages: 7
ISSN: 1463-9076
DOI: https://doi.org/10.1039/c6cp05486b(external)
Abstract
We report on a study of the exchange tunneling reaction D + HD -> D-2 + H in a pure solid HD matrix and in a D-2 matrix with a 0.23% HD admixture at temperatures between 130 mK and 1.5 K. We found that the exchange reaction rates, k(exHD) similar to 3 x 10(-27) cm(3) s(-1) in the pure HD matrix, and k(exD2) = 9(4) x 10(-28) cm(3) s(-1) in the D-2 matrix, are nearly independent of temperature within this range. This confirms the quantum tunnelling nature of these reactions, and their ability to proceed at temperatures down to absolute zero. Based on these observations we concluded that exchange tunneling reaction H + H-2 -> H-2 + H should also proceed in a H-2 matrix at the lowest temperatures. On the other hand, the recombination of H atoms in solid H-2 and D atoms in solid D-2 is substantially suppressed at the lowest temperatures as a result of a decreased probability of resonant tunneling of atoms when they approach each other.
We report on a study of the exchange tunneling reaction D + HD -> D-2 + H in a pure solid HD matrix and in a D-2 matrix with a 0.23% HD admixture at temperatures between 130 mK and 1.5 K. We found that the exchange reaction rates, k(exHD) similar to 3 x 10(-27) cm(3) s(-1) in the pure HD matrix, and k(exD2) = 9(4) x 10(-28) cm(3) s(-1) in the D-2 matrix, are nearly independent of temperature within this range. This confirms the quantum tunnelling nature of these reactions, and their ability to proceed at temperatures down to absolute zero. Based on these observations we concluded that exchange tunneling reaction H + H-2 -> H-2 + H should also proceed in a H-2 matrix at the lowest temperatures. On the other hand, the recombination of H atoms in solid H-2 and D atoms in solid D-2 is substantially suppressed at the lowest temperatures as a result of a decreased probability of resonant tunneling of atoms when they approach each other.
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