4350-82-7Relevant academic research and scientific papers
Oxidative decarboxylation of cyclohexane monocarboxylic acid as a degenerate branching chain reaction II. Mechanism
Heberger,Keszler,Vidoczy,Gal,Cotarca,Delogu
, p. 1303 - 1307 (2007/10/02)
Based on the experimental results obtained studying the oxidative decarboxylation of cyclohexane monocarboxylic acid and published earlier, a mechanism is suggested, according to which in the thermal oxidation two main chain carrier radicals exist: tertiary and secondary peroxy radicals yielding cyclohexanone as well as hydroxy and keto acids in parallel reaction sequences. Carbon dioxide is formed in both pathways independently. The corresponding hydroperoxide molecules, formed during oxidation, decompose partly into radicals and partly into molecules resulting in degenerate branching and chemiluminescence phenomena, respectively. The rate determining termination is the cross combination process between secondary and tertiary peroxy radicals. The combinatorial generation of the mechanism of the thermal process and its reduction enabled the construction of the sequence network of the formation of products indicating that the primary attack of the hydrogen abstraction (secondary or tertiary) determines the product distribution.
Oxidative Decarboxylation of Cyclohexane Monocarboxylic Acid as a Degenerate Branching Chain Reaction. I. Kinetics
Nemes, I.,Heberger, K.,Keszler, A.,Vasvari, G.,Gal, D.,et al.
, p. 75 - 81 (2007/10/02)
Kinetics of product accumulation during the oxidative decarboxylation of cyclohexane monocarboxylic acid has been followed by GCMS, inhibitor and chemiluminescence methods.Results indicate that in the degenerate branching chain process selective (peroxy) radicals abstract predominantly tertiary hydrogen atoms from the substrate while non-selective (e.g. hydroxyl, alkoxy) radicals attack also secondary hydrogen atoms.The rate constant of the chain propagation was found to be kp = 7.5*106 exp (-57.6 kJ mol-1/RT) l mol-1 s-1.Furthermore it has been established, that the oxidative decarboxylation proceeds via two parallel pathways: one resulting in cyclohexanone, while the other avoiding the formation of the latter. Key Words: Chemical Kinetics / Elementary Reactions / Radicals / Oxidation, decarboxylation
