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Kinetics and mechanism for the oxidation of 1,1,1‐trichloroethane
Author(s) -
Nelson Linda,
Shanahan Imelda,
Sidebottom Howard W.,
Treacy Jack,
Nielsen Ole J.
Publication year - 1990
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550220603
Subject(s) - chemistry , radical , reaction rate constant , radiolysis , arrhenius equation , kinetics , reactivity (psychology) , chlorine , molecule , photochemistry , medicinal chemistry , organic chemistry , activation energy , physics , alternative medicine , pathology , quantum mechanics , medicine
The reaction mechanisms for oxidation of CH 3 CCl 2 and CCl 3 CH 2 radicals, formed in the atmospheric degradation of CH 3 CCl 3 have been elucidated. The primary oxidation products from these radicals are CH 3 CClO and CCl 3 CHO, respectively. Absolute rate constants for the reaction of hydroxyl radicals with CH 3 CCl 3 have been measured in 1 atm of Argon at 359, 376, and 402 K using pulse radiolysis combined with UV kinetic spectroscopy giving (OH + CH 3 CCl 3 ) = (5.4 ± 3) 10 −12 exp(−3570 ± 890/ RT ) cm 3 molecule −1 s −1 . A value of this rate constant of 1.3 × 10 −14 cm 3 molecule −1 s −1 at 298 K was calculated using this Arrhenius expression. A relative rate technique was utilized to provide rate data for the OH + CH 3 CCl 3 reaction as well as the reaction of OH with the primary oxidation products. Values of the relative rate constants at 298 K are: (OH + CH 3 CCl 3 ) = (1.09 ± 0.35) × 10 −14 , (OH + CH 3 CClO) = (0.91 ± 0.32) × 10 −14 , (OH + CCl 3 CHO) = (178 ± 31) × 10 −14 , (OH + CCl 2 O) < 0.1 × 10 −14 ; all in units of cm 3 molecule −1 s −1 . The effect of chlorine substitution on the reactivity of organic compounds towards OH radicals is discussed.