Branching Ratio Measurements of the Predissociation of 12C16O by Time-Slice Velocity-Map Ion Imaging in the Energy Region from 106 250 to 107 800 cm –1
- Univ. of California, Davis, CA (United States); Univ. of California, San Francisco, CA (United States)
- Univ. of California, Davis, CA (United States); Chinese Academy of Sciences (CAS), Beijing (China)
- Univ. of California, Davis, CA (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Photodissociation of CO is a fundamental chemical mechanism for mass-independent oxygen isotope fractionation in the early Solar System. Branching ratios of photodissociation channels for individual bands quantitatively yield the trapping efficiencies of atomic oxygen resulting into oxides. We measured the branching ratios for the spin-forbidden and spin-allowed photodissociation channels of 12C16O in the vacuum ultraviolet (VUV) photon energy region from 106 250 to 107 800 cm–1 using the VUV laser time-slice velocity-map imaging photoion technique. The excitations to four 1Π bands and three 1Σ+ bands of 12C16O were identified and investigated. The branching ratios for the product channels C(3P) + O(3P), C(1D) + O(3P), and C(3P) + O(1D) of these predissociative states strongly depend on the electronic and vibrational states of CO being excited. Furthermore, by plotting the branching ratio of the spin-forbidden dissociation channels versus the excitation energy from 102 500 to 110 500 cm–1 that has been measured so far, the global pattern of the 1Π–3Π interaction that plays a key role in the predissociation of CO is revealed and discussed.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Laboratory Directed Research and Development (LDRD) Program
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1477706
- Report Number(s):
- LA-UR-18-28856
- Journal Information:
- Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory, Vol. 122, Issue 41; ISSN 1089-5639
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Photodissociation branching ratios for several absorption bands of 12 C 16 O from 108,500 to 109,220 cm −1
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journal | January 2020 |
Rotational dependence of the branching ratios and fragment angular distributions for the photodissociation of 12 C 16 O in the Rydberg 4p(2) and 5p(0) complex region (92.84–93.37 nm)
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journal | January 2019 |
Channel-resolved rotationally dependent predissociation rate constants reveal the state-to-state dissociation dynamics of carbon monoxide in electronically excited states
|
journal | January 2020 |
Strong and selective isotope effect in the vacuum ultraviolet photodissociation branching ratios of carbon monoxide
|
journal | July 2019 |
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