ABSTRACT
During decomposition of aliphatic nitrocompounds in the gas phase the following two mechanisms mainly occur: the molecular mechanism, which consists in H N 0 2 elimination through the 5-membered transition state,
C H C NO? * i — O k
O
(3.1) tf — O k \ / : O C = C + H N 0 2
C--Cyy / \
and the radical mechanism, i.e., C — N bond breaking with the formation of free radicals [3.1]
R N 0 2 - > R + N 0 2 . (3.2)
Mononitroalkanes, having an H atom in a-position, a-halogen nitrocompounds of R C H 2 C H X N 0 2 ( X = Hal) type, and many other ctnitroolefines are decomposed at moderate temperatures (up to 300°C) by the first mechanism. /zewe-Dinitroalkanes, 1,1,1-trinitroalkanes, a,adihalogenated R C X 2 N 0 2 due to a reduced C — N bond strength are decomposed by the second mechanism. At sufficiently high temperatures,
36 Aliphatic Nitrocompounds
reaction (3.2) predominates in all cases because its rate constant has a larger pre-exponential factor as compared with reaction (3.1).
