A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Tunneling chemical exchange reaction D plus HD -> D-2 + H in solid HD and D-2 at temperatures below 1 K
Tekijät: Sheludiakov S, Ahokas J, Jarvinen J, Zvezdov D, Lehtonen L, Vainio O, Vasiliev S, Lee DM, Khmelenko VV
Kustantaja: ROYAL SOC CHEMISTRY
Julkaisuvuosi: 2016
Journal: Physical Chemistry Chemical Physics
Tietokannassa oleva lehden nimi: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Lehden akronyymi: PHYS CHEM CHEM PHYS
Vuosikerta: 18
Numero: 42
Aloitussivu: 29600
Lopetussivu: 29606
Sivujen määrä: 7
ISSN: 1463-9076
DOI: https://doi.org/10.1039/c6cp05486b
Tiivistelmä
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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