Premium
The gas‐phase decomposition of alkoxy radicals
Author(s) -
Batt L.
Publication year - 1979
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.550110905
Subject(s) - chemistry , radical , alkoxy group , thermal decomposition , tetrafluoride , nitric acid , decomposition , inert gas , atmospheric temperature range , peroxide , medicinal chemistry , inorganic chemistry , alkyl , analytical chemistry (journal) , organic chemistry , thermodynamics , physics
It is shown that it is possible to obtain good data for the rate constant for the decomposition of alkoxy radicals [RO] by using nitric oxide as a radical trap. Two experimental systems have been used. The first system involves the use of dialkyl peroxides [(RO) 2 ] as thermal sources of alkoxy radicals. The peroxide concentration was ∼10 −4 M , nitric oxide ∼2 × 10 −4 M , and the extent of reaction was ∼10%. The total pressure was altered using carbon tetrafluoride as an inert gas. The mechanism isHence R 2 / R 3 = k 2 [ N O]/ k 3 . Our previous studies show that k 2 lies in the range 10 10.3±0.2 M −1 ·sec −1 . The second system employs alkyl nitrites [RONO] as a thermal source of alkoxy radicals. The experimental conditions are very similar, except that we chose to use an atmosphere of nitric oxide for initial experiments. If anything nitric oxide appears to be superior to carbon tetrafluoride as an energy transfer agent. The mechanism isHence R 3 = k 1 ' k 3 [ RO NO]/( k 3 + k 2 + k 6 [ N O]). Results are given for R = t ‐Am, s ‐Bu, t ‐Bu, i ‐Pr, Et, and Me. In addition the first unequivocal evidence is given for the pressure dependence of k 3 when R = t ‐Bu. The implications for atmospheric chemistry and combustion are also discussed.