Investigation of CO photolysis at 193 nm using oxygen-atom two-photon laser-induced fluorescence near 225.6 nm

• Published in: The Journal of chemical physics 1990-10, Vol.93 (7), p.4791-4795
• Main Authors: MERROW, C. N, FORCH, B. E
• Format: Article
• Language: English
• Subjects: Atomic and molecular physics; Exact sciences and technology; Molecular properties and interactions with photons; Photon interactions with molecules; Physics
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.458669

The photolysis of carbon monoxide (CO) with the ArF excimer laser (193 nm) has been investigated using a pump and probe laser experiment. Ground state oxygen 2p4 (3P2,1,0) atomic fragments which are produced in the ArF laser photolysis of CO are detected by monitoring the 844.7 nm laser-induced fluorescence following the two photon excitation of the oxygen 2p4 (3P2,1,0) →2p33p(3P2,1,0) transitions near 225.6 nm. The slope (n) of an Ln–Ln plot of the fluorescence signal intensity vs laser photolysis energy yields n=1.90±0.09, which indicates a quadratic dependence on the 193 nm photolysis of CO. A mechanism is proposed where the initial absorption of one ArF photon produces CO (a 3Π,v′=2), which subsequently absorbs one additional ArF laser photon into a dissociative state with suspected triplet character.