Measurements of line strengths in the HO sub 2. nu. sub 1 overtone band at 1. 5. mu. m using an InGaAsP laser

Journal Article · Thu Aug 22 04:00:00 EDT 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100170a022· OSTI ID:7017518

Johnson, T J; Wienhold, F G; Burrows, J P; Harris, G W ^[1]; Burkhard, H ^[2]

---

1. Max Planck Inst. for Chemistry, Mainz (Germany)
2. DBP Telekom Research Inst., Darmstadt (Germany)

The hydroperoxyl radical, HO{sub 2}, is a pivotal atmospheric species, being closely coupled to OH, the most important oxidant in both tropospheric and stratospheric chemistry. The authors report the first observation of resolved rotational-vibrational overtone (2{nu}{sub 1}) absorptions of the hydroperoxyl radical (HO{sub 2}) in the 1.5-{mu}m region, using two-tone frequency modulation spectroscopy (TTFMS) with an InGaAsP laser diode and White-cell optics. Photolysis of Cl{sub 2}/H{sub 2}O{sub 2} mixtures was used to produce the HO{sub 2}, and the concentration was determined by modulated-photolysis UV absorption spectroscopy. The line center adsorption cross sections for the strongest lines ranged between 1.3 {times} 10{sup {minus}20} and 10 {times} 10{sup {minus}20} cm{sup 2} molecule{sup {minus}1} under Doppler-limited conditions. For the strongest line this corresponds to an integrated line strength S of 1.6 {times} 10{sup {minus}21} cm{sup 2} molecule{sup {minus}1} cm{sup {minus}1}, a line strength of the same order of magnitude as lines previously observed in the relatively weak {nu}{sub 1} fundamental.

• OSTI ID: 7017518
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:17; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
CHEMICAL REACTIONS
DATA
DECOMPOSITION
DOPPLER BROADENING
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FREQUENCY MODULATION
HYDROPEROXY RADICALS
INFORMATION
INFRARED SPECTRA
LINE BROADENING
MODULATION
NUMERICAL DATA
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADICALS
ROTATIONAL STATES
SPECTRA
SPECTROSCOPY
VIBRATIONAL STATES