THE Ã-~X ELECTRONIC TRANSITIONS OF THE CH2BrOO AND CH2ClOO RADICALS IN THE NEAR INFRARED REGION

Huang, Meng

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https://hdl.handle.net/2142/79132 Copy

Description

Title

THE Ã-~X ELECTRONIC TRANSITIONS OF THE CH2BrOO AND CH2ClOO RADICALS IN THE NEAR INFRARED REGION

Author(s)

Huang, Meng

Contributor(s)

• Miller, Terry A.
• Kline, Neal

Issue Date

26-Jun-15

Keyword(s)

Atmospheric science

Abstract

Moderate resolution cavity ring-down spectroscopy(CRDS) is used to obtain the textit{~{A}-~{X}} electronic transition of the CH${_2}$BrOO and CH${_2}$ClOO radicals in the near-infrared region at room temperature. The CH${_2}$BrOO radical was generated by 248nm excimer laser photolysis of a gas mixture of CH${_2}$Br${_2}$, O${_2}$ and inert gas. The CH${_2}$ClOO radical was generated similarly except for using CH${_2}$ClI as the precursor. In both spectra, the first strong transition is located near 6800 cm${^{-1}}$, and is assigned as the origin band. Several transitions are observed in the region between the origin and 9000 cm${^{-1}}$. A strong vibrational transition is observed around 800 cm${^{-1}}$ to the blue of the origin and attributed to the OO stretch which is characteristic of the peroxy radical spectra. Our analysis of the vibrational structure is conducted using frequencies and Franck-Condon factors based on electronic structure calculations. Rotational structure analyses with ab-initio calculated rotational constants and dipole moments show good agreement with the contour of the origin band. Numerous transitions around the origin band in the CH${_2}$BrOO radical spectrum can be explained by excitation from low-lying torsional levels in the textit{~{X}} state that are populated at room temperature.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79132

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