Abstract

Abstract We report a theoretical study on the photochemical reactivity of formaldehyde carbonyl oxide H2COO, a compound of atmospheric relevance. Calculations are carried out at the CASSCF and CASPT2 levels with extended basis sets. We are particularly interested in three important unimolecular processes: isomerization into dioxirane, syn/anti isomerization and dissociation into formaldehyde and atomic oxygen. The results suggest that the photochemical reactivity of H2COO in the troposphere is strongly linked to the properties of the second singlet excited state a 1 A ′ ( π → π * ) because it is energetically accessible from the ground state and has a large oscillator strength. Construction of potential energy curves reveals that photochemical isomerization into dioxirane is very unlikely to occur whereas syn/anti isomerization should be favorable. Besides, in the a1A′ state, carbonyl oxide spontaneously dissociates into formaldehyde H2CO and atomic oxygen O ( 1 D ) in close relationship to the excited 1 B 2 state of the isoelectronic ozone molecule occurring in Hartley’s band.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.