Absolute rate constants for hydrogen abstraction from aldehydes and conformational studies of the corresponding aromatic acyl radicals

1984 ◽  
Vol 106 (18) ◽  
pp. 5252-5256 ◽  
Author(s):  
C. Chatgilialoglu ◽  
L. Lunazzi ◽  
D. Macciantelli ◽  
G. Placucci







1968 ◽  
Vol 46 (16) ◽  
pp. 2661-2666 ◽  
Author(s):  
J. A. Howard ◽  
K. U. Ingold

Rate constants have been measured for hydrogen abstraction from four aralkanes and addition to two aralkenes by five secondary and one primary peroxy radical. These rate constants appear to show a slight dependence on the structure of the attacking peroxy radicals which may be due to the inductive effects of the substituents on the radical. The secondary and primary peroxy radicals are generally about 2–4 times more reactive than tertiary peroxy radicals in abstraction and 4–8 times more reactive in addition. The lower reactivity of tertiary peroxy radicals is probably due to steric factors.



1968 ◽  
Vol 46 (6) ◽  
pp. 1017-1022 ◽  
Author(s):  
J. A. Howard ◽  
K. U. Ingold ◽  
M. Symonds

Absolute rate constants have been measured for the reactions of cumylperoxy radicals with a number of hydrocarbons. The cumylperoxy radicals were produced from cumene hydroperoxide. Sufficient hydroperoxide was present to ensure that only cumylperoxy radicals were involved in the rate-determining propagation reaction.Primary and secondary deuterium isotope effects have been measured for propagation and termination in the oxidation of cumene. The rate of hydrogen atom abstraction from ring-substituted cumenes by cumylperoxy radicals can be correlated by the Hammett equation using σ+ substituent constants, ρ = −0.29. Primary and secondary peroxy radicals are about 3–5 times more reactive in hydrogen abstraction than tertiary peroxy radicals.



1975 ◽  
Vol 53 (22) ◽  
pp. 3374-3382 ◽  
Author(s):  
R. P. Overend ◽  
G. Paraskevopoulos ◽  
R. J. Cvetanović

A fast flash photolysis kinetic spectrophotometer capable of measuring rates of up to 105 s−1 is described. The rates of hydrogen abstraction from H2, CH4, C2H6, and C3H8 by OH radicals at 295 ± 2 K, have been measured in the gas phase by hydroxyl resonance absorption spectrophotometry. The influence of secondary reactions on the measured rates and the derivation of the absolute rate constants is discussed in detail.The absolute rate constants in units of cm3 mol−1 s−1 were found to be: [Formula: see text][Formula: see text][Formula: see text] and [Formula: see text]





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