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Tahsildaran F FS, Moore B, Bashiri T, Otani H, Djuricanin P, Malekfar R, Farahbod AH, Momose T. VUV photochemistry and nuclear spin conversion of water and water-orthohydrogen complexes in parahydrogen crystals at 4 K. Phys Chem Chem Phys 2021; 23:4094-4106. [PMID: 33586746 DOI: 10.1039/d0cp04523c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Samples of H2O, HDO, and D2O were isolated in solid parahydrogen (pH2) matrices and irradiated by vacuum ultraviolet (VUV) radiation at 147 nm. Fourier-Transform Infrared (FTIR) spectra showed a clear depletion of D2O and an enrichment of both HDO and H2O by 147 nm irradiation. These irradiation-dependent changes are attributed to the production of OH and/or OD radicals through photodissociations of H2O, HDO, and D2O. The radicals subsequently react with the hydrogen matrix, leading to the observed enrichment of H2O. No trace of isolated OH or OD was detected in the FTIR spectra, indicating that the OH/OD radicals react with the surrounding matrix hydrogen molecules via quantum tunneling within our experimental timescale. The observed temporal changes in concentrations, especially the increase of HDO concentration during VUV irradiation, can be interpreted by a model with a rapid conversion from orthohydrogen (oH2) to pH2 in water-oH2 complexes upon VUV photodissociation, indicating either the acceleration of the nuclear spin conversion (NSC) of H2 due to the magnetic moment of the intermediate OH/OD radical, or the preferential reaction of the OH/OD radical with a nearby oH2 molecule over other pH2 molecules. We have also identified and quantified an anomalously slow NSC of H2O and D2O complexed with oH2 in solid pH2.
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Affiliation(s)
- Fatemeh S Tahsildaran F
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada. and Atomic and Molecular Physics Group, Department of Physics, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran
| | - Brendan Moore
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
| | - Termeh Bashiri
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
| | - Hatsuki Otani
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
| | - Pavle Djuricanin
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
| | - Rasoul Malekfar
- Atomic and Molecular Physics Group, Department of Physics, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran
| | - Amir Hossein Farahbod
- Research School of Plasma Physics and Nuclear Fusion, Research Institute of Nuclear Sciences and Technologies, AEOI, Tehran, Iran
| | - Takamasa Momose
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
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Matsuda S, Yamazaki M, Harata A, Yabushita A. CO 2 Formation Yields from Different States of CO Adsorbed on Amorphous Solid Water under 157 nm Photoirradiation. CHEM LETT 2018. [DOI: 10.1246/cl.171121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Shohei Matsuda
- Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Motoki Yamazaki
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Akira Harata
- Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
| | - Akihiro Yabushita
- Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580, Japan
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Hama T, Watanabe N. Surface Processes on Interstellar Amorphous Solid Water: Adsorption, Diffusion, Tunneling Reactions, and Nuclear-Spin Conversion. Chem Rev 2013; 113:8783-839. [DOI: 10.1021/cr4000978] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tetsuya Hama
- Institute of Low Temperature
Science, Hokkaido University, N19W8 Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Naoki Watanabe
- Institute of Low Temperature
Science, Hokkaido University, N19W8 Kita-ku, Sapporo, Hokkaido 060-0819, Japan
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Photochemical reaction processes during vacuum-ultraviolet irradiation of water ice. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2013. [DOI: 10.1016/j.jphotochemrev.2013.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hama T, Yokoyama M, Yabushita A, Kawasaki M. Role of OH radicals in the formation of oxygen molecules following vacuum ultraviolet photodissociation of amorphous solid water. J Chem Phys 2010; 133:104504. [DOI: 10.1063/1.3474999] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hama T, Yabushita A, Yokoyama M, Kawasaki M, Watanabe N. Formation mechanisms of oxygen atoms in the O(D21) state from the 157nm photoirradiation of amorphous water ice at 90K. J Chem Phys 2009; 131:114510. [DOI: 10.1063/1.3194798] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hama T, Yabushita A, Yokoyama M, Kawasaki M, Andersson S. Desorption of hydroxyl radicals in the vacuum ultraviolet photolysis of amorphous solid water at 90 K. J Chem Phys 2009; 131:054508. [PMID: 19673575 DOI: 10.1063/1.3191731] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have studied the desorption dynamics of OH radicals from the 157 nm photodissociation of amorphous solid water (ASW) as well as H(2)O(2) deposited on an ASW surface at 90 K. The translational and internal energy distributions of OH were measured using resonance-enhanced multiphoton ionization methods. These distributions are compared to reported molecular dynamics calculations for the condensed phase photodissociation of water ice and also reported results for the gas phase photodissociation of H(2)O at 157 nm. We have confirmed that OH radicals are produced from two different mechanisms: one from primary photolysis of surface H(2)O of ASW, and the other being secondary photolysis of H(2)O(2) photoproducts on the ASW surface after prolonged irradiation at 157 nm.
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Affiliation(s)
- Tetsuya Hama
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
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