Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen

We report infrared spectroscopic studies of H₂ ortho-para (o/p) conversion in solid hydrogen doped with Clatoms at 2 K while the Cl+H₂(v=1)→HCl+H infrared-induced chemical reaction is occurring. The Cl-atom doped hydrogen crystals are synthesized using 355 nm in situ photodissociation of Cl₂ precurs...

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Published in:Физика низких температур
Date:2010
Main Authors: Raston, P.L., Kettwich, S.C., Anderson, D.T.
Format: Article
Language:English
Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2010
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Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/117038
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Cite this:Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen / P.L. Raston, S.C. Kettwich, D.T. Anderson // Физика низких температур. — 2010. — Т. 36, № 5. — С. 495-503. — Бібліогр.: 31 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-117038
record_format dspace
spelling Raston, P.L.
Kettwich, S.C.
Anderson, D.T.
2017-05-19T09:06:26Z
2017-05-19T09:06:26Z
2010
Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen / P.L. Raston, S.C. Kettwich, D.T. Anderson // Физика низких температур. — 2010. — Т. 36, № 5. — С. 495-503. — Бібліогр.: 31 назв. — англ.
0132-6414
PACS: 66.30.Ma, 67.80.F–, 67.80.dj
https://nasplib.isofts.kiev.ua/handle/123456789/117038
We report infrared spectroscopic studies of H₂ ortho-para (o/p) conversion in solid hydrogen doped with Clatoms at 2 K while the Cl+H₂(v=1)→HCl+H infrared-induced chemical reaction is occurring. The Cl-atom doped hydrogen crystals are synthesized using 355 nm in situ photodissociation of Cl₂ precursor molecules. For hydrogen solids with high ortho-H₂ fractional concentrations (Xo=0.55), the o/p conversion kinetics is dominated by Cl-atom catalyzed conversion with a catalyzed conversion rate constant Kcc=1.16(11) min⁻¹ and the process is rate-limited by ortho-H₂ quantum diffusion. For hydrogen crystals with low ortho-H₂ concentrations (Xo=0.03), single-exponential decay of the ortho-H₂ concentration with time is observed which is attributed to H-atom catalyzed o/p conversion by the H-atoms produced during the infrared-induced Cl+H₂ reaction. The measured H-atom catalyzed o/p conversion kinetics indicates the H-atoms are mobile under these conditions in agreement with previous ESR measurements.
This work was sponsored in part by the Chemistry Division of the US National Science Foundation (CHE 03-16268, CHE 08-48330).
en
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
Физика низких температур
Nanostructures and Impurity Centers in Cryogenic Environment
Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
spellingShingle Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
Raston, P.L.
Kettwich, S.C.
Anderson, D.T.
Nanostructures and Impurity Centers in Cryogenic Environment
title_short Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
title_full Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
title_fullStr Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
title_full_unstemmed Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen
title_sort infrared studies of ortho-para conversion at cl-atom and h-atom impurity centers in cryogenic solid hydrogen
author Raston, P.L.
Kettwich, S.C.
Anderson, D.T.
author_facet Raston, P.L.
Kettwich, S.C.
Anderson, D.T.
topic Nanostructures and Impurity Centers in Cryogenic Environment
topic_facet Nanostructures and Impurity Centers in Cryogenic Environment
publishDate 2010
language English
container_title Физика низких температур
publisher Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
format Article
description We report infrared spectroscopic studies of H₂ ortho-para (o/p) conversion in solid hydrogen doped with Clatoms at 2 K while the Cl+H₂(v=1)→HCl+H infrared-induced chemical reaction is occurring. The Cl-atom doped hydrogen crystals are synthesized using 355 nm in situ photodissociation of Cl₂ precursor molecules. For hydrogen solids with high ortho-H₂ fractional concentrations (Xo=0.55), the o/p conversion kinetics is dominated by Cl-atom catalyzed conversion with a catalyzed conversion rate constant Kcc=1.16(11) min⁻¹ and the process is rate-limited by ortho-H₂ quantum diffusion. For hydrogen crystals with low ortho-H₂ concentrations (Xo=0.03), single-exponential decay of the ortho-H₂ concentration with time is observed which is attributed to H-atom catalyzed o/p conversion by the H-atoms produced during the infrared-induced Cl+H₂ reaction. The measured H-atom catalyzed o/p conversion kinetics indicates the H-atoms are mobile under these conditions in agreement with previous ESR measurements.
issn 0132-6414
url https://nasplib.isofts.kiev.ua/handle/123456789/117038
citation_txt Infrared studies of ortho-para conversion at Cl-atom and H-atom impurity centers in cryogenic solid hydrogen / P.L. Raston, S.C. Kettwich, D.T. Anderson // Физика низких температур. — 2010. — Т. 36, № 5. — С. 495-503. — Бібліогр.: 31 назв. — англ.
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