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Kinetics of the HBr‐catalyzed photoisomerization of the allyl halides
Author(s) -
Abell Paul I.,
Adolf Paul K.
Publication year - 1969
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.550010602
Subject(s) - chemistry , photochemistry , allylic rearrangement , isomerization , allyl bromide , halide , allyl chloride , photoisomerization , catalysis , bromide , hydrogen chloride , hydrogen bromide , medicinal chemistry , bromine , inorganic chemistry , organic chemistry
The kinetics of the gas phase bond isomerization of allyl fluoride, allyl chloride and allyl bromide, catalyzed by HBr and ultraviolet light, has been studied in the temperature range of 150–250° and at pressures of 3.5 to 50 mm. The reactions are very clean, first order in allyl halide and HBr, and have a light intensity exponent of unity. A quantum yield for allyl chloride of 3200 indicates a chain reaction. Dilution with inert gases is almost without effect, indicating that excited state intermediates are not involved. A small wall effect is observed. The evidence indicates a free radical reaction, involving hydrogen abstractions by bromine atoms, with replacement at the other end of the allylic radical.