Uncatalyzed, Regioselective Oxidation of Saturated Hydrocarbons in an Ambient Corona Discharge

Abstract

Atmospheric pressure chemical ionization (APCI) in air or in nitrogen with just traces of oxygen is shown to yield regioselective oxidation, dehydrogenation, and fragmentation of alkanes.Ozone is produced from ambient oxygen in situ and is responsible for the observed ion chemistry,w hich includes partial oxidation to ketones and C À Cc leavage to give aldehydes.T he mechanism of oxidation is explored and relationships between ionic species produced from individual alkanes are established. Unusually,dehydrogenation occurs by water loss.C ompetitive incorporation into the hydrocarbon chain of nitrogen versus oxygen as amode of ionization is also demonstrated.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Ta2+-mediated ammonia synthesis from N2and H2at ambient temperature

“…For instance, complexes with single (14-32) and multiple (15,(33)(34)(35)(36)(37)(38)(39) transition metal centers, small metal clusters (40)(41)(42)(43)(44)(45)(46)(47)(48), and also, main group compounds (49-52) have been found to be able to split dinitrogen. The activation of N-N bonds by oriented external electric fields (53,54) followed by insertion of, for example, a nitrogen atom in the C-C bonds of alkanes has been reported as well (55,56). Another promising approach is based on the electrochemical cleavage of N 2 to produce ammonia (11,31,32,51,(57)(58)(59)(60).…”

Modern Plasma‐based Desorption/Ionization: From Atoms and Molecules to Chemical Synthesis

“…Furthermore, these products formed on a mass-spectrometric timescale. These reactions have been decoupled from a mass spectrometer with the gas-phase products collected offline for determination with other techniques (Ayrton et al, 2018). In a corona discharge reactor under a reflux for 3 hr, octane was oxidized and unsaturated regioselectively to form only 3-octen-2-one as characterized by GC-MS.…”

Determination of volatile non intentionally added substances coming from a starch-based biopolymer intended for food contact by different gas chromatography-mass spectrometry approaches

“…Generally, GC-APCI is well known to generate molecular weight diagnostic M + • and [M+H] + ions [35,36]. However, a few studies demonstrated that in ambient corona discharge, the addition of N and O to hydrocarbons via ion/molecule reactions is possible [37]. In this work, we carried out an ionization experiment by injecting individual 100 pg/L methanolic solutions of adiponitrile, furfural, methyl palmitate, and dipropyl phthalate into the APGC-Q (Supplementary 2).…”

“…When ionization takes place in a nitrogen atmosphere with traces of oxygen at low corona current, nitrogen addition is strongly favored over oxygen addition. At higher currents, the opposite is true [37]. Oxygen is known to produce ozone in corona discharges [39] and is likely responsible for the oxidation processes, including dipolar insertion and protonation to [M+3O+H] + , and sequential loss of one or two molecules of water, obtaining [M+2O−H] + and [M+O-3H] + .…”

“…Oxygen is known to produce ozone in corona discharges [39] and is likely responsible for the oxidation processes, including dipolar insertion and protonation to [M+3O+H] + , and sequential loss of one or two molecules of water, obtaining [M+2O−H] + and [M+O-3H] + . The [M−H+O] + species can be associated with O O bond cleavage and rearrangement to generate ketones or C C bond heterolysis resulting in smaller chain aldehydes [37]. In the proximity of the corona discharge needle, the NO + species can form [40] and react with the analyte molecules to give [M+NO] + ions.…”