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Title: Ephemeral collision complexes mediate chemically termolecular transformations that affect system chemistry [Ephemeral collision complexes induce chemically termolecular transformations that affect global chemistry]

Termolecular association reactions involve ephemeral collision complexes—formed from the collision of two molecules—that collide with a third and chemically inert ‘bath gas’ molecule that simply transfers energy to/from the complex. These collision complexes are generally not thought to react chemically on collision with a third molecule in the gas-phase systems of combustion and planetary atmospheres. Such ‘chemically termolecular’ reactions, in which all three molecules are involved in bond making and/or breaking, were hypothesized long ago in studies establishing radical chain branching mechanisms, but were later concluded to be unimportant. Here, with data from ab initio master equation and kinetic-transport simulations, we reveal that reactions of H+O 2 collision complexes with other radicals constitute major kinetic pathways under common combustion situations. These reactions are also found to influence flame propagation speeds, a common measure of global reactivity. As a result, analogous chemically termolecular reactions mediated by ephemeral collision complexes are probably of significance in various combustion and planetary environments.
Authors:
ORCiD logo [1] ;  [2]
  1. Columbia Univ., New York, NY (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Nature Chemistry
Additional Journal Information:
Journal Volume: 2017; Journal ID: ISSN 1755-4330
Publisher:
Nature Publishing Group
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Chemical Sciences, Geosciences, and Biosciences Division
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1400399