Cyclopentylperoxyl and cyclohexylperoxyl radicals in aqueous solution: a study by product analysis and pulse radiolysis. [Cyclopentane]
Radiolysis of N/sub 2/O/O/sub 2/ (4:1 v/v) saturated aqueous solutions of cyclopentane generates cyclopentylperoxyl radicals which decay by a second-order rate process (2k = 1.5 x 10/sup 7/ M/sup -1/s/sup -1/) and give rise to the following products (G values in parentheses): cyclopentanone (1.7), cyclopentanol (0.8), glutaraldehyde (1.2), 5-hydroxypentanal (0.8), organic peroxidic material (0.5), and H/sub 2/O/sub 2/ (1.7); oxygen is consumed with G = 5.0. The corresponding data for cyclohexane solutions are as follows (2k = 1.2 x 10/sup 7/ M/sup -1/ s/sup -1/): cyclohexanone (2.5), cyclohexanol (0.9), total aldehydes (0.8), organic peroxidic material (0.9), H/sub 2/O/sub 2/ (1.6), and oxygen uptake (4.0). During the bimolecular decay of the cycloalkylperoxyl radicals small amounts (G approx. 0.5) of HO/sub 2/ (H/sup +/ + O/sub 2//sup -/) are formed. In the rate-determining step a short-lived tetroxide is apparently formed and breaks up by four main routes: (i) O/sub 2/, cycloalkanol, and cycloalkanone, (ii) H/sub 2/O/sub 2/ and two molecules of cycloalkanone, (iii) O/sub 2/ and two omega-formylalkyl radicals (from which the acyclic aldehydes are formed), and (iv) O/sub 2/ and two cycloalkoalkoxyl radicals. The cycloalkoxyl radicals undergo a 1,2-H shift, a reaction which eventually leads to the formation of the intermediate O/sub 2//sup -/. In the cyclopentane system the fragmentation (mainly the concerted process iii) is the most important single process (40%) whereas in the cyclohexane system this route does not exceed 15%. A fragmentation of the acyclic radicals is not observed. 22 references, 3 figures, 1 table.
- Research Organization:
- Max-Planck-Institut fuer Strahlenchemie, Muelheim, Germany
- OSTI ID:
- 5893626
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 88:8
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALDEHYDES
G VALUE
CYCLOALKANES
RADIOLYSIS
CYCLOHEXANOL
CYCLOHEXANONE
KETONES
ABSORPTION SPECTROSCOPY
AQUEOUS SOLUTIONS
CHEMICAL REACTION KINETICS
CYCLOHEXANE
DECAY
EXPERIMENTAL DATA
GAS CHROMATOGRAPHY
HYDROGEN PEROXIDE
HYDROPEROXY RADICALS
HYDROXYL RADICALS
NITROUS OXIDE
OXYGEN
PULSED IRRADIATION
WATER
ALCOHOLS
ALKANES
CHALCOGENIDES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
DATA
DECOMPOSITION
DISPERSIONS
ELEMENTS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
IRRADIATION
KINETICS
MIXTURES
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PEROXIDES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
REACTION KINETICS
SEPARATION PROCESSES
SOLUTIONS
SPECTROSCOPY
400600* - Radiation Chemistry