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
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