Matrix Isolation Spectroscopy and Nuclear Spin Conversion of Propyne Suspended in Solid Parahydrogen
| Autor: | Alejandro Gutiérrez-Quintanilla, Claudine Crépin, Aaron I. Strom, Michèle Chevalier, Justinas Ceponkus, David T. Anderson |
|---|---|
| Přispěvatelé: | University of Wyoming (UW), Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Vilnius University [Vilnius], SYSIPHE, Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2020 |
| Předmět: |
010304 chemical physics
Chemistry [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus] Kinetics Matrix isolation Rotational–vibrational spectroscopy 010402 general chemistry Spin isomers of hydrogen Propyne 01 natural sciences Molecular physics 0104 chemical sciences 3. Good health parahydrogen matrix chemistry.chemical_compound methyl rotation 0103 physical sciences Molecule nuclear spin conversion [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] Physical and Theoretical Chemistry infrared spectroscopy Spectroscopy Spin (physics) |
| Zdroj: | Journal of Physical Chemistry A Journal of Physical Chemistry A, American Chemical Society, 2020, 124 (22), pp.4471-4483. ⟨10.1021/acs.jpca.0c02900⟩ |
| ISSN: | 1520-5215 1089-5639 |
| Popis: | International audience; Parahydrogen (pH2) quantum solids are excellent matrix isolation hosts for studying the rovibrational dynamics and nuclear spin conversion (NSC) kinetics of molecules containing indistinguishable nuclei with nonzero spin. The relatively slow NSC kinetics of propyne (CH3CCH) isolated in solid pH2 is employed as a tool to assign the rovibrational spectrum of propyne in the 600–7000 cm–1 region. Detailed analyses of a variety of parallel (ΔK = 0) and perpendicular (ΔK=±1) bands of propyne indicate that the end-over-end rotation of propyne is quenched, but K rotation of the methyl group around the C3 symmetry axis still persists. However, this single-axis K rotation is significantly hindered for propyne trapped in solid pH2 such that the energies of the K rotational states do not obey simple energy-level expressions. The NSC kinetics of propyne follows first-order reversible kinetics with a 287(7) min effective time constant at 1.7 K. Intensity–intensity correlation plots are used to determine the relative line strengths of individual ortho- and para-propyne rovibrational transitions, enabling an independent estimation of the ground vibrational state effective A″ constant of propyne. |
| Databáze: | OpenAIRE |
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