Nitrogen incorporation in saturated aliphatic C6-C8 hydrocarbons and ethanol in low-pressure nitrogen plasma generated by a hollow cathode discharge ion source.
Ion/molecule reactions of saturated hydrocarbons (n-hexane, cyclohexane, n-heptane, n-octane and isooctane) in 28-Torr N2 plasma generated by a hollow cathode discharge ion source were investigated using an Orbitrap mass spectrometer. It was found that the ions with [M+14](+) were observed as the major ions (M: sample molecule). The exact mass analysis revealed that the ions are nitrogenated molecules, [M+N](+) formed by the reactions of N3 (+) with M. The reaction, N3 (+) + M → [M+N](+) + N2 , were examined by the density functional theory calculations. It was found that N3 (+) abstracts the H atom from hydrocarbon molecules leading to the formation of protonated imines in the forms of R'R″CNH2 (+) (i.e. C-H bond nitrogenation). This result is in accord with the fact that elimination of NH3 is the major channel for MS/MS of [M+N](+) . That is, nitrogen is incorporated in the C-H bonds of saturated hydrocarbons. No nitrogenation was observed for benzene and acetone, which was ascribed to the formation of stable charge-transfer complexes benzene⋅⋅⋅⋅N3 (+) and acetone⋅⋅⋅⋅N3 (+) revealed by density functional theory calculations. Copyright © 2016 John Wiley & Sons, Ltd.
Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511, Japan.|Institute of Ion-Plasma and Laser Technologies, Durmon Yoli 33, Tashkent, 100125, Uzbekistan.
Dilshadbek T
DT
Usmanov
Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511, Japan.
Lee Chuin
LC
Chen
Clean Energy Research Center, University of Yamanashi, Takeda-4, Kofu, Yamanashi, 400-8511, Japan.
Kenzo
K
Hiraoka
Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, 496 Izumi, Chikugo, Fukuoka, 833-0041, Japan.
Hiroshi
H
Wada
Plant Biophysics/Biochemistry Research Laboratory, Faculty of Agriculture, Ehime University, Matsuyama, Japan.
Hiroshi
H
Nonami
Department of Material Science, Nara Institute of Science and Technology, Takayama-cho, 8916-5, Ikoma, Nara, 630-0101, Japan.
Shinichi
S
Yamabe
N3+; carbenium ion; hollow cathode discharge; imine; nitrogen plasma; nitrogenation; saturated hydrocarbons