The infrared multiphoton decomposition of dimethylnitramine and diethylnitramine in the gas phase
under almost collisionless conditions has been studied with a tunable CO2 laser. The steady state rate
coefficient for their unimolecular decomposition were found to be kDENA(st) = 105.5 ± 0.1(I/MW cm–2) s–1,
and kDENA(st) = 105.2 ± 0.1(I/MW cm–2) s–1, for laser intensities in the range 3–15 MW cm –2. The dependence
of rate constants and product yields on laser fluence have indicated that the unimolecular dissociation
of both nitramines occurs via scission of the N-NO2 bond, and the main secondary reaction leading to
the final photolysis products (nitrosamine and nitroxide) is the oxidation reaction of nascent dialkylamino
radical with parent nitramine or NO2 product.