Gas phase radiation chemistry of ethyl bromide. [Gamma radiation; effects of oxygen addition]

Journal Article · Thu Jul 01 04:00:00 EDT 1976 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100555a003· OSTI ID:7341312

Frank, A J; Hanrahan, R J

The ..gamma.. radiolysis of ethyl bromide has been investigated at 100 Torr pressure and 23/sup 0/C. In the pure system between an absorbed dose of 1.0 x 10/sup 20/ and 1.5 x 10/sup 20/ eV/g the major products and their respective G values are as follows: hydrogen bromide, 3.89; ethane, 2.70; ethylene, 2.17; acetylene, 0.31; hydrogen, 1.39; 1,1-dibromoethane, 0.88; 1,2-dibromoethane, 0.12; vinyl bromide, 0.32; methane, 0.083; methyl bromide, 0.080; and bromoform, 0.0078. When oxygen is added, the G values in this dose range become the following: hydrogen bromide, 4.89; ethane, 0.31; ethylene, 0.78; acetylene, 0.27; hydrogen, 1.38; 1,1-dibromoethane, 0.028; 1,2-dibromoethane, 0.56; vinyl bromide, 0.0; methane 0.03; methyl bromide, 0.32; and bromoform, 0.0034. Bromine is also formed with a G value of 2.4 when oxygen is added. The presence of hydrogen and acetylene in the radiolysis indicates that these species must be formed from higher energy processes not accessible in the 253.7-nm photolysis, which was studied in a parallel investigation. The product distribution indicates that the probabilities of single bond rupture in the primary event are approximately C/sub 2/H/sub 5/--Br:C/sub 2/H/sub 4/Br--H:CH/sub 3/--CH/sub 2/Br = 1.00:0.40:0.06. Either a hot hydrogen atom abstraction reaction or direct molecular H/sub 2/ elimination accounts for about 16 percent of the hydrogen yield. Strong similarities in dose-yield plots suggest that many of the secondary processes involved in the photolysis are important in the radiolysis of ethyl bromide as well. The high pressure mass spectrometry of the system indicates the role of ionic species. Differences in radiolytic behavior of ethyl chloride, bromide, and iodide can largely be explained in terms of the energetics of the primary and secondary processes in each system.

• Research Organization: Univ. of Florida, Gainesville
• OSTI ID: 7341312
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 80:14; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400600* -- Radiation Chemistry
BROMINATED ALIPHATIC HYDROCARBONS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMISTRY
CHLORINATED ALIPHATIC HYDROCARBONS
CRYOGENIC FLUIDS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUIDS
G VALUE
GAMMA RADIATION
GAS ANALYSIS
HALOGENATED ALIPHATIC HYDROCARBONS
HOT ATOM CHEMISTRY
IODINATED ALIPHATIC HYDROCARBONS
IONIZING RADIATIONS
LOW PRESSURE
MASS SPECTROSCOPY
MEDIUM TEMPERATURE
NONMETALS
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
OXYGEN
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADIOCHEMISTRY
SPECTROSCOPY
YIELDS