Hydrogen-Deuterium Kinetic Isotope Effect at Very High Temperature

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.1732532· OSTI ID:4810251

Johnston, Harold S.; Tschuikow-Roux, Eugene

The kinetic isotope effect for the reaction CF/sub 3/ x CH/sub 2/ D/sub 2/ yields CF/sub 3/H + CHD/sub 2/ or CF/sub 3/D + CH/sub 2/D was studied in a shock tube between 1000 and 2000 deg K where CF/sub 3/ radicals were produced by thermal decomposition of CF/sub 3/N/sub 2/CF/sub 3/. ln the reaction zone gas compositions wereof noble gases >> CH/sub 2/D/sub 2/ >> CF/sub 3/N/sub 2/CF/sub 3/ ; and in this ration in final products CF/sub 3/H/CF/suib 3/D was equal to the ratio of rate constants kH/kD. The data are represented empirically by lnkH/kD = lnl.400 + 0.42 x l0/sup 6//T/sup 2/. A London-PolanyiEyring-Sato potential energy surface was constructed, where Sato's parameter was fitted to give the correct activation energy, and the frequencies and zero-point energy of the activated complex were then found from curvatures through the saddlepoint of the potential energy surface. At very high temperatures activated complex theory predicts Ink/sub H//K/sub D/ = In1.402 + 0.502 x10/sup 6//T/ssup 2/ 0.069 x l0/ sup 12//T/sup 4/, in fair agreement with experiment. (auth)

• Research Organization: Univ. of California, Berkeley
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-010004
• OSTI ID: 4810251
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 36; ISSN JCPSA6; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACTIVATION
BOHR-MOTTELSON MODEL
CHEMICAL REACTIONS
CHEMISTRY
COLLECTIVE MODEL
COMPLEXES
CONFIGURATION
COUPLING
CROSS SECTIONS
DECOMPOSITION
DEFORMATION
DEUTERIUM
DEUTERIUM COMPOUNDS
DIAGRAMS
ELECTRIC POTENTIAL
ENERGY
EXCITATION
FLUORINE
FREE RADICALS
FREQUENCY
GASES
HIGH TEMPERATURE
HYDROGEN
INTERACTIONS
ISOTOPE EFFECTS
JOURNAL
KNUDSEN EFFUSION
LABORATORY EQUIPMENT
MEASURED VALUES
METHANE
NUCLEAR MODELS
NUCLEAR STRUCTURE
NUCLEAR THEORY
NUCLEONS
ORGANIC FLUORINE COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RARE GASES
REACTION KINETICS
SHELL MODELS
SHOCK TUBES
SHOCK WAVES
SURFACES
TEMPERATURE
THERMAL SHOCK
THERMAL STRES