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Strong and selective isotope effect in the vacuum ultraviolet photodissociation branching ratios of carbon monoxide
- Source :
- Nature Communications, Vol 10, Iss 1, Pp 1-8 (2019), Nature Communications
- Publication Year :
- 2019
- Publisher :
- Springer Science and Business Media LLC, 2019.
-
Abstract
- Rare isotope (13C, 17O and 18O) substitutions can substantially change absorption line positions, oscillator strengths and photodissociation rates of carbon monoxide (CO) in the vacuum ultraviolet (VUV) region, which has been well accounted for in recent photochemical models for understanding the large isotopic fractionation effects that are apparent in carbon and oxygen in the solar system and molecular clouds. Here, we demonstrate a strong isotope effect associated with the VUV photodissociation of CO by measuring the branching ratios of 12C16O and 13C16O in the Rydberg 4p(2), 5p(0) and 5s(0) complex region. The measurements show that the quantum yields of electronically excited C atoms in the photodissociation of 13C16O are dramatically different from those of 12C16O, revealing strong isotope effect. This isotope effect strongly depends on specific quantum states of CO being excited, which implies that such effect must be considered in the photochemical models on a state by state basis.<br />Carbon monoxide is the main C and O reservoir in interstellar media, where it undergoes photochemistry. The authors show that isotopic substitution affects not only its absorption. spectrum and photodissociation rates but also the branching ratio, key to understand isotopic. fractionation in the solar system
- Subjects :
- Chemical physics
Science
General Physics and Astronomy
Photochemistry
Article
General Biochemistry, Genetics and Molecular Biology
Spectral line
symbols.namesake
chemistry.chemical_compound
Kinetic isotope effect
Physics::Chemical Physics
Nuclear Experiment
lcsh:Science
Astrophysics::Galaxy Astrophysics
Laboratory astrophysics
Multidisciplinary
Isotope
Branching fraction
Photodissociation
General Chemistry
chemistry
Excited state
Physics::Space Physics
Rydberg formula
symbols
lcsh:Q
Astrophysics::Earth and Planetary Astrophysics
Carbon monoxide
Subjects
Details
- ISSN :
- 20411723
- Volume :
- 10
- Database :
- OpenAIRE
- Journal :
- Nature Communications
- Accession number :
- edsair.doi.dedup.....fc09440230ab245c90d6ccd66e8d0427