The NO and non-energetic OH radical reactivity: characterization and reaction scheme

Abstract

The solid phase reaction between NO and non‐energetic OH radicals was investigated using helium as a dilution medium at 3 K. The species generated were characterized by in situ Fourier transform infrared (FTIR) spectroscopy. The choice of solid phase experiment was motivated by its potential applications in the field of atmospheric chemistry and astrochemistry. Unfortunately, under such conditions, broad absorption bands with overlapping features are observed, and as a consequence, the assignment of each signal to the newly formed specie is risky. This is the reason why, in order to attribute all the absorption bands observed in the solid phase FTIR spectra, similar experiments were carried out by replacing the dilution medium with neon whereas other experimental parameters were retained. As a result, all produced species are trapped in neon matrix showing narrow peaks so the elucidation of spectral signals is simple. Furthermore, the correlation of the spectra in solid phase and in neon matrix helps to avoid the intricacies in understanding the spectrum observed in solid phase reactivity. This approach allowed us to characterize the formation of nitrous acid (HONO), nitrogen dioxide (NO2), nitrosyl hydride (HNO), nitric acid (HNO3), nitrous oxide (N2O) and ozone (O3). The concentration effect of reagents on the end products was also investigated. Based on these experimental results, reaction pathways are proposed to explain the formation of all the observed products.

Simultaneous hydrogenation and UV-photolysis experiments of NO in CO-rich interstellar ice analogues; linking HNCO, OCN−, NH2CHO, and NH2OH

“…This is particularly important under the extremely cold conditions of the interstellar medium (ISM), where gas-phase and surface reactions are strongly affected by even small endothermicity or the presence of an activation barrier. Recently, frozen NO molecules have been linked to the formation of other species, like NH2OH, NO2, N2O, and HNO2 (Joshi et al 2012, Congiu et al 2012a, Congiu et al 2012b, Fedoseev et al 2012, Minissale et al 2014, Ioppolo et al 2014a. In space, NO molecules are primarly formed in the gas-phase through the reaction: N (g) + OH (g) → NO (g) + H (g) (1), (see Herbst & Klemperer 1973, McGonagle et al 1990, Gerin et al 1992.…”

May interstellar leucine react with NO radicals present in interstellar/interplanetary medium? An ion-trap mass spectrometry study

“…Furthermore, the introduction of pure NO in the ion trap may lead to hard collisions with the ions that are trapped, thus resulting in their fragmentations. Therefore, an experimental setup allowing the dilution of NO radicals into He was developed [27] in order to avoid these two side effects.…”

Solid state chemistry of nitrogen oxides – Part II: surface consumption of NO2

“…7,8 Laboratory studies of non-energetic surface processing showed that, for instance, ammonia (NH 3 ), hydroxylamine (NH 2 OH), nitrogen dioxide (NO 2 ), dinitrogen trioxide (N 2 O 3 ), nitrous acid (HNO 2 ), and nitric acid (HNO 3 ) are efficiently formed at low temperatures through hydrogenation of N-atoms, NO + H, NO + O 2 , NO + NO 2 , NO + OH, and NO 2 + OH reactions, respectively. [9][10][11][12][13][14][15][16] In the accompanying paper, hereafter referred to as Part I, 17 we investigate the oxygenation of solid NO (NO + O/O 2 /O 3 ) at a Division of Geological and Planetary Sciences, California Institute of Technology,…”