Nitrogen‐containing organic products from the treatment of liquid toluene with plasma‐activated N₂ gas

Abstract

This proof-of-principle study explored the possibility to form nitrogen-containing organic products via exposure of liquid toluene to a flow of molecular nitrogen, at room temperature and atmospheric pressure, activated by dielectric barrier discharges. N-containing organic compounds indeed formed under these conditions, including benzonitrile, a high-value chemical that is industrially synthesized from toluene under demanding conditions. Toluene-derived higher hydrocarbons, as well as oxygen-containing derivatives, were also detected, the latter due to efficient reactions of residual oxygen in the system. A mechanistic description of the observed chemistry is provided, together with guidelines for increasing the selectivity for C-N forming reactions and the development of this approach into a novel synthetic approach for high-value organic N-containing chemicals.

Does non-thermal plasma modify biopolymers in solution? A chemical and mechanistic study for alginate

“…21–26 Beyond plasma medicine, the effect of NTP treatment on organic molecules has also been extensively studied for other applications, in particular for the purpose of wastewater decontamination from persistent organic pollutants and recently new perspectives have been explored to synthesize highly valuable chemicals in a cheap and green way. 27…”

“…[21][22][23][24][25][26] Beyond plasma medicine, the effect of NTP treatment on organic molecules has also been extensively studied for other applications, in particular for the purpose of wastewater decontamination from persistent organic pollutants and recently new perspectives have been explored to synthesize highly valuable chemicals in a cheap and green way. 27 The use of biopolymers, especially of those able to form hydrogels, has been very limited in the field of plasma medicine. The two main aims have been the use of hydrogels to mimic tissues for studies related to RONS penetration and as vehicles for storage and local delivery of RONS.…”

Excited-State N Atoms Transform Aromatic Hydrocarbons into N-Heterocycles in Low-Temperature Plasmas

“…Understanding chemical pathways for the formation of N -heterocycles can give insights into their origin in primordial earth and extraterrestrial environments. A new pathway for the formation of N -heterocycles has recently been reported in a nitrogen-based low-temperature plasma by direct substitution of carbon with nitrogen in aromatic hydrocarbons. , However, the mechanism by which a stable aromatic ring may be broken and a carbon atom replaced with a nitrogen atom from elemental N 2 has been unclear because the reactive species in low-temperature plasmas are only partly characterized and the reaction mechanisms are not fully understood. − …”

“…A new pathway for the formation of N-heterocycles has recently been reported in a nitrogen-based low-temperature plasma by direct substitution of carbon with nitrogen in aromatic hydrocarbons. 1,2 However, the mechanism by which a stable aromatic ring may be broken and a carbon atom replaced with a nitrogen atom from elemental N 2 has been unclear because the reactive species in low-temperature plasmas are only partly characterized and the reaction mechanisms are not fully understood. 3−6 Plasmas are ionized gases and considered the fourth state of matter; they are highly energetic, reactive, and responsive to electric and magnetic fields.…”

Discriminating alkylbenzene isomers with tandem mass spectrometry using a dielectric barrier discharge ionization source

“…Near the ignition voltage of the plasma, at 2.4 kV pp , molecular ions [M] +• are formed by reaction with N At an increased operating voltage of 3.4 kV pp (Figure 2B), nitrogen addition [M + N] + and replacement [M-C + N] + products are formed, because N-atom density35 and the population of electronically excited state N-atoms36,37 increase exponentially with energy in filamentary DBDs. The replacement product [M-C + N] + has been previously reported in DBDIs as corresponding to protonated N-heterocycle,38,39 whereas the nitrogen addition [M + N] + product may correspond to a protonated amine, N-atom adduct, or N-azepine.…”