UV Absorption Spectrum and Photodissociation Channels of the Simplest Criegee Intermediate (CH₂OO)
The lowest-lying singlet states of the simplest Criegee intermediate (CH2OO) have been characterized along the O-O dissociation coordinate using explicitly correlated MRCI-F12 electronic structure theory and large active spaces. It is found that a high-level treatment of dynamic electron-correlation is essential to accurately describe these states. a significant well on the B-state is identified at the MRCI-F12 level with an equilibrium structure that differs substantially from that of the ground X-state. This well is presumably responsible for the apparent vibrational structure in some experimental UV absorption spectra, analogous to the structured Huggins band of the iso-electronic ozone. the B-state potential in the Franck-Condon region is sufficiently accurate that an absorption spectrum calculated with a one-dimensional model agrees remarkably well with experiment.
R. Dawes et al., "UV Absorption Spectrum and Photodissociation Channels of the Simplest Criegee Intermediate (CH₂OO)," Journal of the American Chemical Society, vol. 137, no. 1, pp. 50-53, American Chemical Society (ACS), Jan 2015.
The definitive version is available at https://doi.org/10.1021/ja510736d
Center for High Performance Computing Research
Keywords and Phrases
Absorption spectra; Electromagnetic wave absorption; Electronic structure; Light absorption; Photodissociation; Criegee intermediates; Electronic structure theory; Equilibrium structures; High-level treatment; Lowest-lying singlet state; One-dimensional model; UV absorption spectrum; Vibrational structures; Absorption spectroscopy; formaldehyde; alkene; ozone; Article; calculation; dissociation; experimental study; geometry; simplest criegee intermediate; ultraviolet spectroscopy; chemistry; photochemistry; ultraviolet spectrophotometry; Alkenes; Ozone; Photochemical Processes; Spectrophotometry, Ultraviolet
International Standard Serial Number (ISSN)
Article - Journal
© 2015 American Chemical Society (ACS), All rights reserved.
01 Jan 2015