Nuclear Spin Symmetry Conservation in 1H2 16O Investigated by Direct Absorption FTIR Spectroscopy of Water Vapor Cooled Down in Supersonic Expansion
| Autor: | Pierre Asselin, P. Soulard, Pascale Roy, Martin Fournier, Olivier Pirali, Thérèse R. Huet, Xavier Michaut, A.A. Vigasin, Audrey Moudens, Manuel Goubet, Robert Georges |
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| Přispěvatelé: | Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), LERMA Cergy (LERMA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires d'Orsay (ISMO), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Ligne AILES, Synchrotron SOLEIL, A.M.Obukhov Institute of Atmospheric Physics (IAP), Russian Academy of Sciences [Moscow] (RAS), The authors are grateful to SOLEIL and the AILES staff for providing technical support under the proposal 20120156. X.M. and A.M. are grateful to the French National Research Agency (Project ANR GASOSPIN No. 09-BLAN-0066-01) for the financial support of the calculation code development. A.V. acknowledges partial support from the RFBR Grant 15-05-00736 and the Russian Acad. Sci. Program 7. This work was supported by the Programme National 'Physique et Chimie du Milieu Interstellaire' (PCMI) of CNRS/INSU with INC/INP cofunded by CEA and CNES. The authors warmly thank the reviewers for their valuable comments and suggestions, which have helped to improve the quality of our manuscript., ANR-09-BLAN-0066,GASOSPIN(2009), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Expansion
Absorption of water Supersonic expansions Stretching vibrations Vapour pressure of water Analytical chemistry Rotational temperature chemistry.chemical_element Spin dynamics 010402 general chemistry Mole fraction Water-molecule clustering 01 natural sciences Rovibrational lines Isomers Nuclear spin isomer 0103 physical sciences Physics::Atomic and Molecular Clusters Equilibrium temperatures Stretching Physics::Chemical Physics Physical and Theoretical Chemistry 010306 general physics Water vapor [PHYS]Physics [physics] Argon Fourier transform infrared spectroscopy Rotational–vibrational spectroscopy CRESU Molecules Vapor partial pressure 0104 chemical sciences Oxygen chemistry Mixtures Water absorption Reservoirs (water) Absorption (chemistry) Molecular physics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
| Zdroj: | Journal of Physical Chemistry A Journal of Physical Chemistry A, American Chemical Society, 2017, 121 (40), pp.7455-7468. ⟨10.1021/acs.jpca.7b06858⟩ Journal of Physical Chemistry A, 2017, 121 (40), pp.7455-7468. ⟨10.1021/acs.jpca.7b06858⟩ |
| ISSN: | 1089-5639 1520-5215 |
| Popis: | International audience; We report the results of an experimental study related to the relaxation of the nuclear spin isomers of the water molecule in a supersonic expansion. Rovibrational lines of both ortho and para spin isomers were recorded in the spectral range of H2O stretching vibrations at around 3700 cm-1 using FTIR direct absorption. Water vapor seeded in argon, helium, or oxygen or in a mixture of oxygen and argon was expanded into vacuum through a slit nozzle. The water vapor partial pressure in the mixture varied over a wide range from 1.5 to 102.7 hPa, corresponding to a water molar fraction varying between 0.2 and 6.5%. Depending on expansion conditions, the effect of water vapor clustering was clearly seen in some of our measured spectra. The Boltzmann plot of the line intensities allowed the H2O rotational temperatures in the isentropic core and in the lateral shear layer probed zones of the planar expansion to be determined. The study of the OPR, i.e., the ratio of the ortho to para absorption line intensities as a function of Trot, did not reveal any signs of the OPR being relaxed to the sample temperature. In contrast, the OPR was always conserved according to the stagnation reservoir equilibrium temperature. The conservation of the OPR was found irrespective of whether water molecule clustering was pronounced or not. Also, no effect of the paramagnetic oxygen admixture enhancing OPR relaxation was observed. © 2017 American Chemical Society. |
| Databáze: | OpenAIRE |
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