Carbon and oxygen isotopic fractionation in the products of low-temperature VUV photodissociation of carbon monoxide
The carbon and oxygen isotope fractionations occurring during photodissociation of carbon monoxide (CO) by vacuum ultraviolet photons (91–107 nm) at 80 K were measured and the isotopic fractionations due to direct and indirect predissociation processes individually quantified. The isotopic fractionations depend on the photodissociation wavelength. Slope values (δ'17O/δ'18O) in oxygen three-isotope space range from 0.75 to 1.1. The isotopic composition of the products depends on the dissociation dynamics at the upper electronic state (perturbation and coupling associated with that state), which in turn modulates the isotope effect (in this case an enrichment of minor isotopes) inside the gas column due to the saturation of major isotopologue (isotope self-shielding). An explanation in terms of isotope self-shielding would require a quantum yield of one for photodissociation of all isotopologues which is not consistent with the data.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 1439404
- Alternate ID(s):
- OSTI ID: 1542332
- Journal Information:
- Chemical Physics, Journal Name: Chemical Physics Vol. 514 Journal Issue: C; ISSN 0301-0104
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- Netherlands
- Language:
- English
Web of Science
Data from: Carbon and oxygen isotopic fractionation in the products of low-temperature VUV photodissociation of carbon monoxide
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