Multichannel Radical–Radical Reaction Dynamics of NO + Propargyl Probed by Broadband Rotational Spectroscopy

Abstract

Chirped-pulse rotational spectroscopy in a quasi-uniform flow has been used to investigate the reaction dynamics of a multichannel radical–radical reaction of relevance to planetary atmospheres and combustion. In this work, the NO + propargyl (C3H3) reaction was found to yield six product channels containing eight detected species. These products and their branching fractions (%), are as follows: HCN (50), HCNO (18), CH2CN (12), CH3CN (7.4), HC3N (6.2), HNC (2.3), CH2CO (1.3), HCO (1.8). The results are discussed in light of previous unimolecular photodissociation studies of isoxazole and prior potential energy surface calculations of the NO + C3H3 system. The results also show that the product branching is strongly influenced by the excess energy of the reactant radicals. The implications of the title reaction to the planetary atmospheres, particularly to Titan, are discussed.

Direct D-atom Incorporation in Radicals: An Overlooked Pathway for Deuterium Fractionation

“…The density declines by several orders of magnitude in the detection region preventing the collisional attenuation of the millimeter-wave signal. The characteristics of the quasi-uniform flow are described in depth in our earlier publication (Broderick et al 2018) and the details of current millimeter-wave circuitry are outlined in our previous publications (Abeysekera et al 2015;Gurusinghe et al 2021a;Dias et al 2022).…”

10 Years of the ACS PHYS Astrochemistry Subdivision

“…In this virtual special issue, N 2 O is reacted with C( 3 P), producing rate coefficients for such chemical processes, 21 and a similar study on fluoromethane and calcium atomic cations is also reported. 22 Additionally, the deuterated ethynyl radical is reacted with propylene producing a wealth of hydrocarbons, 23 NO + the propargyl radical generates branching ratios for eight common astrochemical products, 24 furan + H 2 reactions generate various c-C 4 H x O (x = 4−8) species, 25 myriad nitrous oxides are synthesized in H 2 O−N 2 O/N 2 ice mixtures, 26,27 dinitriles are shown to be produced from gas-phase reactions of cyano radicals and cyanoethane, 28 and porous amorphous solid water appears to catalyze interstellar organic chemistry. 29 From theory, the earliest molecule in the universe (HeH + ) is most efficiently rotationally excited by collisions with H 2 , 30 H 2 CCS and HCCSH are likely not detected since they are destroyed through barrierless reactions with atomic hydrogen, 31 and MgNC reacts with water clusters to produce the known HMgNC molecule along with other Mg-containing species.…”