Abstract

The Army uses nitrated compounds as explosives and propellants. The ability to selectively nitrate materials is a much-needed process. Laser-induced chemistry possesses the potential to drive some reactions in an efficient and selective manner. Laser-induced chemistry may be useful in driving nitration reactions toward specific products. Reported herein are the results of several successful attempts to laser-induce the reaction of nitrogen dioxide with hydrocarbons of 3,4, and 5 carbons. Specifically, the tunable continuous wave (cw) infrared laser was used to drive the reaction between nitrogen dioxide, NO₂, and propane, <i>n</i>-butane, isobutane, and <i>n</i>-pentane. The major products of the reactions were secondary (tertiary in the isobutane reaction) nitrohydrocarbons, of the same chain length as the reacting hydrocarbon. Some short-chain nitrated compounds were also identified. The yield of 2-nitrobutane observed in the nitration of butane is ~20% on the basis of the depletion of NO₂. The propane reacted with NO₂ to produce mostly 2-nitropropane with a smaller yield of 5-9%. The analogous reaction of pentane produced ~9% of the major product, which is believed to be 2-nitropentane. The isobutane nitration resulted in approximately a 10% yield of 2-methyl-2-nitropropane. The results of these laser-induced reactions are contrasted to the corresponding thermal reactions. The reaction mechanism is also discussed for these two processes.

Effect of hydrocarbon molecular decomposition on palladium-assisted laser-induced plasma ablation

Alireza Moosakhani, Parviz Parvin, Seyedeh Zahra Mortazavi, Ali Reyhani, and Shariar Abachi
Appl. Opt. 56(11) E64-E71 (2017)

Decomposition of ethane molecules at atmospheric pressure using metal assisted laser induced plasma

M. Maleki, P. Parvin, A. Reyhani, S. Z. Mortazavi, A. Moosakhani, Z. Ghorbani, and S. Kiani
J. Opt. Soc. Am. B 32(4) 493-505 (2015)

Femtosecond laser-induced breakdown spectroscopy of surface nitrate chemicals

Tariq Ahmido, Antonio Ting, and Prabhakar Misra
Appl. Opt. 52(13) 3048-3057 (2013)

Temperature- and pressure-dependent midinfrared absorption cross sections of gaseous hydrocarbons

Alexander Grosch, Volker Beushausen, Hainer Wackerbarth, Olaf Thiele, and Thomas Berg
Appl. Opt. 49(2) 196-203 (2010)

Imaging of reaction zones in hydrocarbon–air flames by use of planar laser-induced fluorescence of CH

P. H. Paul and J. E. Dec
Opt. Lett. 19(13) 998-1000 (1994)