Molecular dynamics of O(1D) + CCl4 ? ClO + CCl3 probed by cavity-enhanced sub-THz spectroscopy

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Ryan O'Neal (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Liam Duffy

Abstract: The UV photodissociation of ozone in the atmosphere is known to result in highly reactive oxygen atoms in their excited O(1D) electronic state. Subsequent collisions of these atomic radicals with other atmospheric constituents frequently occur without a barrier. Matsumi and Shamsuddin have previously studied the dynamics of these reactions with chlorinated compounds using vacuum-ultraviolet laser-induced fluorescence spectroscopy. In this thesis, we discuss our recent efforts to revisit these experiments by probing the rovibronic distribution of ClO products in hyperfine detail using a recently developed millimeter wavelength cavity enhanced confocal Fabry-Pe´rot molecular beam spectrometer. In the experiment, ozone is generated and passed over carbon tetrachloride and then the vapor is co-expanded through a pulsed nozzle. The resulting supersonic jet expansion is passed through the beam waste of the Fabry-Pe´rot while a counter propagating 266 nm photolysis laser initiates the formation O(1D) atoms and their subsequent intra-beam collision and reaction with CCl4. The resulting rovibronic state distribution of the ClO products in this PHOTOLOC-like experiment are then used to confirm whether the reaction occurs via a direct abstraction mechanism, as inferred in the earlier studies. The results have only shown ClO in the ground vibrational state (v=0) except for a single signal an excited vibrational state (v=3). As it stands, with no other signals being present in the excited vibrational states, we cannot infer the mechanism or molecular dynamics are involved in the reaction to produce ClO from O(1D) and CCl4. [This abstract has been edited to remove characters that will not display in this system. Please see the PDF for the full abstract.]

Additional Information

Language: English
Date: 2020
Cavity enhanced, CCl4, ClO, Molecular Dynamics, O(1D), Sub-THz Spectroscopy
Molecular dynamics
Molecular emission cavity analysis
Submillimeter waves
Spectrum analysis

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