title: Photochemistry. Evidence for direct molecular oxygen production in CO₂ photodissociation.
abstract: Photodissociation of carbon dioxide (CO2) has long been assumed to proceed exclusively to carbon monoxide (CO) and oxygen atom (O) primary products. However, recent theoretical calculations suggested that an exit channel to produce C + O2 should also be energetically accessible. Here we report the direct experimental evidence for the C + O2 channel in CO2 photodissociation near the energetic threshold of the C((3)P) + O2(X(3)Σ(g)(-)) channel with a yield of 5 ± 2% using vacuum ultraviolet laser pump-probe spectroscopy and velocity-map imaging detection of the C((3)PJ) product between 101.5 and 107.2 nanometers. Our results may have implications for nonbiological oxygen production in CO2-heavy atmospheres.
authors.affiliation: Department of Chemistry, University of California, Davis, CA 95616, USA.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Chemistry, University of California, Davis, CA 95616, USA.
authors.forename: Yih Chung
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Department of Earth and Planetary Sciences, University of California, Davis, CA 95616, USA.
authors.forename: Qing-Zhu
authors.initials: QZ
authors.lastname: Yin
authors.affiliation: Department of Chemistry, University of California, Davis, CA 95616, USA. cyng@ucdavis.edu wmjackson@ucdavis.edu.
authors.forename: C Y
authors.initials: CY
authors.lastname: Ng
authors.affiliation: Department of Chemistry, University of California, Davis, CA 95616, USA. cyng@ucdavis.edu wmjackson@ucdavis.edu.
authors.forename: William M
authors.initials: WM
authors.lastname: Jackson