Hydride transfer reaction dynamics of OD{sup +}+C{sub 3}H{sub 6}

Journal Article · Thu Jun 28 04:00:00 EDT 2007 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2743025· OSTI ID:20991288

Liu, Li; Richards, Elizabeth S; Farrar, James M ^[1]

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1. Department of Chemistry, University of Rochester, Rochester, New York 14627 (United States)

The hydride transfer reaction between OD{sup +} and C{sub 3}H{sub 6} has been studied experimentally and theoretically over the center of mass collision energy range from 0.21 to 0.92 eV using the crossed beam technique and density functional theory calculations. The center of mass flux distributions of the product ions at three different energies are highly asymmetric, with maxima close to the velocity and direction of the precursor propylene beam, characteristic of direct reactions. In the hydride transfer process, the entire reaction exothermicity is transformed into product internal excitation, consistent with mixed energy release in which the hydride ion is transferred with both the breaking and forming bonds extended. At higher collision energies, at least 85% of the incremental translational energy appears in product translation, providing a clear example of induced repulsive energy release. Compared to the related reaction of OD{sup +} with C{sub 2}H{sub 4}, reaction along the pathway initiated by addition of OD{sup +} to the C=C bond in propylene has a critical bottleneck caused by the torsional motion of the methyl substituent on the double bond. This bottleneck suppresses reaction through an intermediate complex in favor of direct hydride abstraction. Hydride abstraction appears to be a sequential process initiated by electron transfer in the triplet manifold, followed by rapid intersystem crossing and subsequent hydrogen atom transfer to form ground state allyl cation and HOD.

• OSTI ID: 20991288
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 24 Vol. 126; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CATIONS
CENTER-OF-MASS SYSTEM
CHEMICAL BONDS
COLLIDING BEAMS
COLLISIONS
DENSITY FUNCTIONAL METHOD
ELECTRON TRANSFER
ETHYLENE
EXCITATION
GROUND STATES
HEAVY WATER
HYDRIDES
PROPYLENE
REACTION KINETICS
TRANSFER REACTIONS