Atom-transfer reaction rates for thermal fluorine atoms with CH/sub 3/X and CF/sub 3/X (X = Br, I)

Journal Article · Thu Aug 20 00:00:00 EDT 1981 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150617a017· OSTI ID:6040222

Iyer, R S; Rowland, F S

The thermal reaction rates at 283/sup 0/K of F atoms have been measured with CH/sub 3/Br, CH/sub 3/I, CF/sub 3/Br, and CF/sub 3/I by use of radioactive /sup 18/F atoms moderated to thermal energies by multiple collisions in gaseous SF/sub 6/ at a pressure of 2700 to 3000 torr. The relative rate constants for these reactions have been measured in competition with addition to C/sub 2/H/sub 2/ and/or abstraction from HI, and have been converted to absolute rate constants by comparison with the rate constant of (1.53 +- 0.12) x 10/sup -10/ cm/sup 3/ molecule/sup -1/ s/sup -1/ for the addition of F to C/sub 2/H/sub 2/. The thermal atom transfer to F of I from CF/sub 3/I, of I and/or H from CH/sub 3/I, and of H from CH/sub 3/Br are all extremely rapid. No reaction was observed with CF/sub 3/Br. The absolute rate constants measured in competition with F addition to C/sub 2/H/sub 2/ are (in units of cm/sup 3/ molecule/sup -1/ s/sup -1/) as follows: F + CH/sub 3/Br ..-->.. HF + CH/sub 2/Br, k/sub 6/ = (6.1 +- 0.7) x 10/sup -11/; F + CH/sub 3/I ..-->.. HF + CH/sub 2/I, F + CH/sub 3/I ..-->.. IF + CH/sub 3/, k/sub 8/ + k/sub 9/ = (1.74 +- 0.15) x 10/sup -10/; F + CF/sub 3/I ..-->.. IF + CF/sub 3/, k/sub 7/ = (1.62 +- 0.16) X 10/sup -10/.

• Research Organization: Univ. of California, Irvine
• DOE Contract Number: AT03-76ER70126
• OSTI ID: 6040222
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 85:17; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400701* -- Radiochemistry & Nuclear Chemistry-- Hot-Atom Chemistry
400702 -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACETYLENE
ALKYNES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BROMINATED ALIPHATIC HYDROCARBONS
CHEMICAL REACTION KINETICS
CHEMISTRY
COMPARATIVE EVALUATIONS
FLUORIDES
FLUORINATED ALIPHATIC HYDROCARBONS
FLUORINE 18
FLUORINE COMPOUNDS
FLUORINE ISOTOPES
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HOT ATOM CHEMISTRY
HOURS LIVING RADIOISOTOPES
HYDRIODIC ACID
HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IODINATED ALIPHATIC HYDROCARBONS
IODINE COMPOUNDS
ISOTOPES
KINETICS
LIGHT NUCLEI
MEDIUM PRESSURE
MEDIUM TEMPERATURE
METHYL BROMIDE
METHYL IODIDE
NUCLEI
ODD-ODD NUCLEI
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
RADIOCHEMISTRY
RADIOISOTOPES
REACTION KINETICS
RECOILS
SULFUR COMPOUNDS
SULFUR FLUORIDES