title: Ionizing radiation-induced destruction of benzene and dienes in aqueous media.
abstract: Pulse radiolysis with spectrophotometric and conductometric detection was utilized to study the formation and reactions of radicals from benzene and dienes in aqueous solutions. The benzene OH adduct, *C6H6OH, reacts with O2 (k = 3 x 10(8) L mol(-1) s(-1)) in a reversible reaction. The peroxyl radical, HOC6H6O2*, undergoes O2*- elimination, bimolecular decay, and reaction with benzene to initiate a chain reaction, depending on the dose rate, benzene concentration, and pH. The occurrence of the chain reaction is demonstrated in low-dose-rate gamma radiolysis experiments where the consumption of O2 was monitored. 1,4-Cyclohexadiene, 1,4-hexadiene, and 1,4-pentadiene form OH-adducts and undergo H-abstraction by O*- radicals. The OH-adducts react with O2 to form peroxyl radicals. These peroxyl radicals, however, do not undergo unimolecular O2*- elimination but rather decay by second-order processes, which lead to subsequent steps of O2*- elimination.
authors.affiliation: Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2155, USA. mohamad@eng.umd.edu
authors.forename: Mohamad
authors.initials: M
authors.lastname: Al-Sheikhly
authors.forename: Dianne L
authors.initials: DL
authors.lastname: Poster
authors.forename: Jung-Chul
authors.initials: JC
authors.lastname: An
authors.forename: Pedatsur
authors.initials: P
authors.lastname: Neta
authors.forename: Joseph
authors.initials: J
authors.lastname: Silverman
authors.forename: Robert E
authors.initials: RE
authors.lastname: Huie
mesh_terms: D000466:Alkadienes / Q000032:analysis*; D001554:Benzene / Q000032:analysis*; D003510:Cyclohexanes / Q000032:analysis; D053138:Cyclohexenes; D005609:Free Radicals; D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D010100:Oxygen / Q000032:analysis; D011675:Pulse Radiolysis; D011839:Radiation, Ionizing; D014867:Water / Q000032:analysis*; D014874:Water Pollutants, Chemical
chemical_list: D000466:Alkadienes; D003510:Cyclohexanes; D053138:Cyclohexenes; D005609:Free Radicals; D014874:Water Pollutants, Chemical; D014867:Water; C048401:1,4-cyclohexadiene; C032726:1,4-hexadiene; D001554:Benzene; D010100:Oxygen