Intramolecular propagation in the oxidation of n-alkanes. Autoxidation of n-pentane and n-octane

Abstract

l-Acetyl-l-methylcyclohexane: bp 68-70°(7 mm) [lit.26 bp 80-8.5°(16 mm)]; 13.8 g (66% based upon 150 mmol of olefin) isolated; ir 1700 cm-1; nmr r 8.0 and 9.0 [sharp s, H3CCOCCH8]; vpc (130°a nd 150°) 18 showed a single compound. The 2,4-DNP had a melting point of 131-132°( lit.26 mp 132°) and the semicarbazone melted at 183-185°(lit.26 mp 186-187°).3,3-Dimethyl[3.2.1]bicyclooctanone-2 (7): bp 30-40°(0.3 mm); ir 1710, 3050, and 1610 cm-1 (the latter indicated olefinic contamination); vpc (200°)18 indicated three compounds present. The distillate, dissolved in petroleum ether (bp 30-60°), was placed upon a column containing 30 g of neutral alumina. Elution with petroleum ether yielded an unidentified olefin, ir 3050 and 1610 cm-1, no carbonyl or hydroxyl absorptions present.Elution with 50% (v/v) benzene-petroleum ether yielded 2 g of 7 (25) O.

Oxidation of crystalline polyethylene

“…This loss is expressed by translational and rotational entropy contributions according to the following expression [58]: elementary reactions rarely involve reactive pathways comprising intramolecular reactions. We evaluate accuracy limits implicit in our calculated kinetic data based on a comparison with corresponding experimental values obtained by Van Sickle and co-workers [52,59], for the intramolecular 1,5-hydrogen shift during auto-oxidation of liquid 2-peroxypentane. Our kinetic estimation for this reaction affords a barrier of 81.9 kJ/mol and log A of 13.1 s −1 ; i.e., in agreement with the corresponding experimental assessment for this reaction, 82.4 kJ/mol and 11.5 s −1 , respectively.…”

An adsorption-precipitation model for the formation of injector external deposits in internal combustion engines

“…We consider the oxidation of an alkane that propagates through intermolecular reactions rather than through intramolecular [65][66][67] onesi.e. we assume that the considered alkane does not have the structural component H-CR 1 -CH2-CR 2 -H, where R 1 and R 2 are alkyl groups (this is valid for heptane and isooctane).…”

エステルの自動酸化反応：ポリオールエステル系潤滑油の酸化劣化反応機構の解明に向けて

“…2) The radicals propagate the chain by intermolecular (reaction (3)) or, in certain circumstances, by intramolecular (reaction (4)) reactions 21), 22) , for example:…”

“…It should be noted that the ester radicals are not simply produced by reactions between the ester substrate and alkoxyl radicals (reactions (21) and (23)). The latter radicals also fragment (reactions (20) and (22)) and to different extents as shown by the formation of methane. This was determined quantitatively and showed that almost all of the methyl radicals can be accounted for as methane and thus abstraction from the parent ester is their most important reaction.…”