Abstraction of hydrogen by methylene

✍ Scribed by J. R. McNesby; R. V. Kelly

• Book ID: 102926280
• Publisher: John Wiley and Sons
• Year: 1971
• Tongue: English
• Weight: 550 KB
• Volume: 3
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550030402

✦ Synopsis

The photolysis of CD&O at 313 nm in the presence of neopentane was carried out over the temperature range 576-706 K. Analysis of the products and isotopic analysis of the methanes demonstrate abstraction of H from neopentane and D from CD&O by methylene. The relative kinetics of abstraction of H and D have been measured over the temperature range, and the absolute value for the collision yield of the abstraction of H from neopentane by CD2 at 653 K has been been estimated to be about 1.5 X 10" mole-' cm3 sec-l, a value 103 times larger than the corresponding reaction of CH3.

(1)

The excited propane then decomposes by random rupture of the two weak bonds:

(2)

In this case, methyl radicals may be produced without any pure abstraction by CD2. Preliminary experiments on the photolysis of CD2CO in the presence of C2H6 at around 600 K revealed, in fact, that CH3 was produced in abundance. This could not have occurred by any mechanism other than reactions (l), (2), and (3). Stabilization of the excited propane by collision was not practical since