ChemInform Abstract: Concise Syntheses of L-Selenomethionine and of L-Selenocystine Using Radical Chain Reactions.

ChemInform ◽  
1987 ◽  
Vol 18 (4) ◽  
Author(s):  
D. H. R. BARTON ◽  
D. BRIDON ◽  
Y. HERVE ◽  
P. POTIER ◽  
J. THIERRY ◽  
...  

Part I. Comparison of nitric oxide and propylene as inhibitors The reduction by propylene of the rate of pressure increase in the decomposition of propaldehyde at 550° has been shown by chemical analysis to represent a true inhibition of the reaction, and not to be due n an important degree to an induced polymerization of the propylene. With propaldehyde and with diethyl ether the limiting values to which the decomposition rates are reduced by nitric oxide and by propylene respectively are the same, although much more propylene is required to produce a given degree of inhibition. From this it is concluded that the limiting rates are more probably those of independent non-chain processes, than those characteristic of stationary states where the inhibitor starts and stops chains with equal efficiency.


1990 ◽  
Vol 31 (18) ◽  
pp. 2565-2568 ◽  
Author(s):  
Judith E. Forbes ◽  
Catherine Tailhan ◽  
Samir Z. Zard

Science ◽  
2018 ◽  
Vol 361 (6406) ◽  
pp. 997-1000 ◽  
Author(s):  
K. O. Johansson ◽  
M. P. Head-Gordon ◽  
P. E. Schrader ◽  
K. R. Wilson ◽  
H. A. Michelsen

Mystery surrounds the transition from gas-phase hydrocarbon precursors to terrestrial soot and interstellar dust, which are carbonaceous particles formed under similar conditions. Although polycyclic aromatic hydrocarbons (PAHs) are known precursors to high-temperature carbonaceous-particle formation, the molecular pathways that initiate particle formation are unknown. We present experimental and theoretical evidence for rapid molecular clustering–reaction pathways involving radicals with extended conjugation. These radicals react with other hydrocarbon species to form covalently bound complexes that promote further growth and clustering by regenerating resonance-stabilized radicals through low-barrier hydrogen-abstraction and hydrogen-ejection reactions. Such radical–chain reaction pathways may lead to covalently bound clusters of PAHs and other hydrocarbons that would otherwise be too small to condense at high temperatures, thus providing the key mechanistic steps for rapid particle formation and surface growth by hydrocarbon chemisorption.


2008 ◽  
pp. 11-27 ◽  
Author(s):  
Hideki Yorimitsu ◽  
Koichiro Oshima

2018 ◽  
Vol 9 (36) ◽  
pp. 7218-7229 ◽  
Author(s):  
Markus Griesser ◽  
Jean-Philippe R. Chauvin ◽  
Derek A. Pratt

Sulfinic acids are characterized to be very good H-atom donors to each of alkyl and alkoxyl radicals. In order to participate in useful radical chain reactions, the sulfonyl radicals must undergo fast propagating reactions to avoid autoxidation, which is surprisingly rate-limited by the reaction of sulfonyl radicals with oxygen.


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