Comment on “A novel and facile decay path of Criegee intermediates by intramolecular insertion reactions via roaming transition states” [J. Chem. Phys. 142, 124312 (2015)]
In a recent article, Nguyen et al. report the discovery of a new decomposition pathway for small Criegee intermediates. Prior to this publication, the lowest known pathway for decomposition of Criegee intermediates involved ring closure to form a dioxirane followed by ring opening to make a methylenebisoxy biradical, which can then isomerize or decompose via a variety of pathways. The new pathway reported by Nguyen et al. involves the partial cleavage of the OO bond of the Criegee intermediate forming nascent H2CO and O(1D) fragments. The O(1D) fragment then orbits around the H2CO fragment in a manner reminiscent of roaming radical reactions and eventually inserts into one of the CH bonds of the H2CO fragment leading directly to formic acid. The authors report saddle point geometries for this pathway determined at a number of different levels of theory in which the distance between the oxygen atom and the formaldehyde varies from 2.0 Å to 3.5 Å depending on the level of theory. Density functional theory (DFT) calculations are found to give more compact, planar saddle point structures while coupled cluster, CCSD(T), and complete active space self consistent field, CASSCF, optimizations lead to looser saddle point structures in which the O atom orbits above the plane of the H2CO fragment.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1392423
- Journal Information:
- Journal of Chemical Physics, Vol. 143, Issue 16; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Water-catalyzed decomposition of the simplest Criegee intermediate CH2OO
|
journal | April 2016 |
Similar Records
A novel and facile decay path of Criegee intermediates by intramolecular insertion reactions via roaming transition states
OH Roaming and Beyond in the Unimolecular Decay of the Methyl-Ethyl-Substituted Criegee Intermediate: Observations and Predictions