Reactions of Allyl Radicals With Olefins

Bryce, W. A.; Ruzicka, D. J.

doi:10.1139/v60-120

Cited by 20 publications

(10 citation statements)

References 12 publications

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“…The high-pressure rate constants for the reactions on the C 5 H 9 surface are included in the ESI † (Table S4), with the values at 1 atm listed in Table S5 (ESI †). The predictions also qualitatively agree with an earlier experimental observation by Bryce and Ruzicka, 49 in which cyclopentene is the dominant product.…”

Section: Addition Reactionssupporting

confidence: 89%

Reactions of allylic radicals that impact molecular weight growth kinetics

Wang

Villano

Dean

2015

Phys. Chem. Chem. Phys.

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The reactions of allylic radicals have the potential to play a critical role in molecular weight growth (MWG) kinetics during hydrocarbon oxidation and/or pyrolysis. Due to their stability (when compared to alkyl radicals), they can accumulate to relatively high concentrations. Thus, even though the rate coefficients for their various reactions are small, the rates of these reactions may be significant. In this work, we use electronic structure calculations to examine the recombination, addition, and abstraction reactions of allylic radicals. For the recombination reaction of allyl radicals, we assign a high pressure rate rule that is based on experimental data. Once formed, the recombination product can potentially undergo an H-atom abstraction reaction followed by unimolecular cyclization and β-scission reactions. Depending upon the conditions (e.g., higher pressures) these pathways can lead to the formation of stable MWG species. The addition of allylic radicals to olefins can also lead to MWG species formation. Once again, cyclization of the adduct followed by β-scission is an important energy accessible route. Since the recombination and addition reactions produce chemically-activated adducts, we have explored the pressure- and temperature-dependence of the overall rate constants as well as that for the multiple product channels. We describe a strategy for estimating these pressure-dependencies for systems where detailed electronic structure information is not available. We also derive generic rate rules for hydrogen abstraction reactions from olefins and diolefins by methyl and allyl radicals.

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Section: Addition Reactionssupporting

confidence: 89%

Reactions of allylic radicals that impact molecular weight growth kinetics

Wang

Villano

Dean

2015

Phys. Chem. Chem. Phys.

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“… For the Diels–Alder reaction to occur, the CC bonds in the polyunsaturated fatty acids (linoleic and linolenic acid) must migrate first to form cis-conjugated dienes. , The cis-conjugated dienes then react with another unsaturated fatty acid (oleic, linoleic, or linolenic acid) to form a cyclohexene-like ring. On the other hand, radical-mediated addition is initiated by the abstraction of hydrogen from the methylene between two CC bonds (allylic position for both CC bonds), which is highly active for radical formation. , The resultant radical can be added to the CC bonds of other unsaturated fatty acids (oleic, linoleic, and linolenic acids). Both reactions consume the CC bonds of the unsaturated fatty acid units to form additional C–C bonds between them.…”

Section: Results and Discussionsupporting

confidence: 92%

“…On the other hand, radical-mediated addition is initiated by the abstraction of hydrogen from the methylene between two CC bonds (allylic position for both CC bonds), which is highly active for radical formation. 31,33 The resultant radical can be added to the CC bonds of other unsaturated fatty acids (oleic, linoleic, and linolenic acids). Both reactions consume the C C bonds of the unsaturated fatty acid units to form additional C−C bonds between them.…”

Section: Resultsmentioning

confidence: 99%

Coproduction of Value-Added Lube Base Oil and Green Diesel from Natural Triglycerides via a Simple Two-Step Process

Jin

Lee

Seo

et al. 2020

Ind. Eng. Chem. Res.

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A versatile process for coproducing green diesel and value-added lube base oil from natural triglycerides (e.g., vegetable oil, waste cooking oil, and microalgal oil) was developed. The twostep reaction process comprises (i) thermal oligomerization of triglycerides via Diels−Alder and/or radical-mediated addition of the CC bonds within the fatty acid units and (ii) catalytic deoxygenation of the oligomerized triglycerides via hydroupgrading. Different triglyceride sources, that is, palm oil, soybean oil, and linseed oil, were investigated as the starting feedstock. Thermal oligomerization of the triglycerides at 300 °C proceeded at the expense of the CC bonds within the unsaturated fatty acid units. Thus, the degree of triglyceride oligomerization was enhanced when the reactant triglycerides contained more unsaturated fatty acid units (palm oil < soybean oil < soybean + linseed oil < linseed oil). The oligomerized triglycerides were subsequently deoxygenated over a Pt-MoO x /TiO 2 catalyst, which converted the oligomerized and monomeric fatty acid units into lube base oil (C 30 −C 54 ) and green diesel (C 15 −C 18 ) fractions, respectively. The produced lube base oils were completely saturated with very high viscosity indexes (>120) and a nondetectable sulfur content, which could meet the specifications of high-quality group III lube base oil.

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“…T h a t C3H5 can abstract hydrogen atoms is well established experimentally (3,(19)(20)(21)(22). Consequently, following the dissociation of propylene,…”

Section: The Reaction Fully Inhibited By Propylenementioning

confidence: 94%

Kinetics and Mechanisms of the Pyrolysis of Dimethyl Ether: Ii. The Reaction Inhibited by Nitric Oxide and Propylene

McKenney¹,

Wojciechowski²,

Laidler³

1963

Can. J. Chem.

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The thermal decomposition of dimethyl ether, inhibited by nitric oxide and by propylene, was studied in the temperature range of 500 to 600' C. About 1.5 mm of nitric oxide gave maximal inhibition, the rate then being approximately 8% of the uninhibited rate. With propylene, approximately 70 mm gave maximal inhibition, the rate being slightly higher than that using nitric oxide (~1 2 . 5 7~ of the uninhibited rate). I n both cases the degree of inhibition was independent of the ether pressure. I n the maximally inhibited regions both reactions are three-halves order with respect to ether pressure. As the pressure of nitric oxide was increased beyond 10-15 mm, the overall rate increased, and in this region the reaction is first order with respect t o both nitric oxide and ether. A 50:50 mixture of CHaOCH3 and CD3OCD8, with enough NO to ensure maximum inhibition, was pyrolyzed. Even a t very low percentage decomposition the CD3H/CD4 ratio was approximately the same as that in the uninhibited deco~nposition, proving that the inhibited reaction is largely a chain process. Detailed inhibition mechanisms are proposed in which the inhibitor is involved both in initiation and termination reactions.

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Reactions of Allyl Radicals With Olefins

Cited by 20 publications

References 12 publications

Reactions of allylic radicals that impact molecular weight growth kinetics

Reactions of allylic radicals that impact molecular weight growth kinetics

Coproduction of Value-Added Lube Base Oil and Green Diesel from Natural Triglycerides via a Simple Two-Step Process

Kinetics and Mechanisms of the Pyrolysis of Dimethyl Ether: Ii. The Reaction Inhibited by Nitric Oxide and Propylene

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