Comparison of experimental and theoretical integral cross sections for D+H sub 2 ( v =1, j =1) r arrow HD( v prime =1, j prime )+H

Journal Article · Thu Aug 01 04:00:00 EDT 1991 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.461016· OSTI ID:5742764

Kliner, D A.V.; Adelman, D E; Zare, R N ^[1]

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1. Department of Chemistry, Stanford University, Stanford, California 94305 (US)

We have measured the nascent HD({ital v}{prime}=1, {ital j}{prime}) product rotational distribution from the reaction D+H{sub 2}({ital v}, {ital j}) in which the H{sub 2} reagent was either thermal ({ital v}=0, {ital j}) or prepared in the level ({ital v}=1, {ital j}=1) by stimulated Raman pumping. Translationally hot D atoms were obtained by uv laser photolysis of DBr or DI. Photolysis of DBr generated D atoms with center-of-mass collision energies ({ital E}{sub rel}) of 1.04 and 0.82 eV, which corresponded to the production of ground state Br and spin--orbit-excited Br*, respectively. The {ital E}{sub rel} values for DI photolysis were 1.38 and 0.92 eV. Quantum-state-specific detection of HD was accomplished via (2+1) resonance-enhanced multiphoton ionization and time-of-flight mass spectrometry. Vibrational excitation of the H{sub 2} reagent results in substantial rotational excitation of the HD({ital v}{prime}=1) product and increases the reaction rate into {ital v}{prime}=1 by about a factor of 4. Although the quantum-mechanical calculation of Blais {ital et} {ital al}. (Chem. Phys. Lett. {bold 166}, 11 (1990)) for the D+H{sub 2}({ital v}=1, {ital j}=1){r arrow}HD({ital v}{prime}=1, {ital j}{prime})+H product rotational distribution at {ital E}{sub rel}=1.02 eV is in qualitative agreement with experiment, it does not quantitatively agree with the measured distribution. Specifically, the calculated distribution is too hot by 2--3 rotational quanta, and the predicted enhancement in the {ital v}{prime}=1 rate with reagent vibrational excitation is too large by 67%{plus minus}9.

• OSTI ID: 5742764
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 95:3; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400701* -- Radiochemistry & Nuclear Chemistry-- Hot-Atom Chemistry
BROMIDES
BROMINE COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
CROSS SECTIONS
DECOMPOSITION
DEUTERIDES
DEUTERIUM
DEUTERIUM COMPOUNDS
ELEMENTS
ENERGY LEVELS
EXCITED STATES
HALIDES
HALOGEN COMPOUNDS
HOT ATOM CHEMISTRY
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN DEUTERIDE
HYDROGEN ISOTOPES
INTEGRAL CROSS SECTIONS
ISOTOPES
LIGHT NUCLEI
MECHANICS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
QUANTUM MECHANICS
RADIOCHEMISTRY
ROTATIONAL STATES
STABLE ISOTOPES