Abstraction by hydrogen atoms from ethylene, propylene, butene‐1, and cis‐ and trans‐butene‐2

Abstract

The position of abstraction by H atoms from ethylene, propylene, butene-1, and cisand trans-butene-2 and the rates of abstraction relative to addition have been measured at 25°C.From ethylene, abstraction relative to addition was 5 3 X lo-*. For propylene, butene-1, cis-butene-2, and trans-butene-2, abstraction occurred on 0.27'0, 1.6%, 1.570, and 0.9% of the reactive encounters, if disproprotionation-combination ratios for ally1 and alkyl radicals are similar to those for alkyl-alkyl pairs.Only allylic abstraction was observed.

Reactions of Recoil Τ Atoms with Liquid Chloroethylenes

“…The differences in the yields of 1,1,2-CH 2 TCC1 3 from cis or trans 1,2-C 2 H 2 C1 2 are not understood.). These yields are not different as those measured from a similar reaction chain starting with recoil 34m Cl atoms, yielding chloroethanes containing two CI atoms more than the target chloroethylenes [14], 7. Other products C 2 HTC1 2 yields from C 2 HC1 3 (Table 5), but our results gave no convincing evidence for the preference of a specific site of addition.…”

“…Controversial information exists about the possibility of thermal [5,7] and even hot [6] Η abstraction. 2.…”

Effect of thermal activation on the reactions of chemically activated sec-butyl radicals

“…Also the formation of butenyl radicals by H abstraction was considered negligible, noting the very small yield of Cg olefins, thought of as the combination products from the butenyl and the butyl radicals. 12 (2) Product Distribution with Respect to Temperature. The relative yield of each reaction product was calculated with respect to the yield of main products except that of methane and the butene isomers.…”

“…of 27 mm, between 300 and 670 K. The inner wall of the reactor was coated with H3BO3 to minimize heterogeneous loss of atomic hydrogen introduced. The axial temperature variation in the reactor zone, defined as the temperature difference between the end section of the inner tube (H2 + H) and the position of the maximum temperature Tmax, was 12 K for Tmax = 680 K, and 10 K for Tmax = 490 K.…”

Zur Reaktion von atomarem Wasserstoff mit 1‐Olefinen

“…Anteile terminaler H-Addition bei 1H -A bst r a k t i o n Sowohl beim, der Uberschaubarkeit seines Produktgemisches wegen, in dieser Hinsicht exemplarisch untersuchten Propen als auch bei den anderen I-Olefinen konnten keinerlei H-Abstraktions folgeprodukte nachgewiesen werden. In Ubereinstimmung mit der Literatur, die den Anteil der Allyl-H-Abstraktion im Vergleich zur Addition mit 0-4% angibt[23,24,28, 291, ist dieser Reaktionsweg als bedeutungslos einzuschatzen.111. F o l g e r e a k t i o n e n n a c h H -A d d i t i o nDie nach terminaler H-Addition gebildeten 2-Alkylradikale unterliegen in allen Olefinsystemen einer chemisch aktivierten /3-Spaltung (vgl.…”