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Photodissociation of Peroxynitric Acid in the Near-IR

Roehl, Coleen M. and Nizkorodov, Sergey A. and Zhang, Hui and Blake, Geoffrey A. and Wennberg, Paul O. (2002) Photodissociation of Peroxynitric Acid in the Near-IR. Journal of Physical Chemistry A, 106 (5). pp. 3766-3772. ISSN 1089-5639. doi:10.1021/jp013536v.

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Temperature-dependent near-IR photodissociation spectra were obtained for several vibrational overtone transitions of peroxynitric acid (HNO_4) with a tunable OPO photolysis/OH laser-induced-fluorescence system. Band-integrated photodissociation cross-sections (∫σ_(diss)), determined relative to that for the 3ν_1 OH stretching overtone, were measured for three dissociative bands. Assuming unit quantum efficiency for photodissociation of 3ν_1 we find 2ν_1 + ν_3 (8242 cm^(-1)) = (1.21 × 10^(-20)) (independent of temperature), 2ν_1 (6900 cm^(-1)) = 4.09 × 10^(-18)* e^((-826.5/T)) (295 K > T > 224 K), and ν_1 + 2ν_3 (6252 cm^(-1)) = 1.87 × 10^(-19)* e^((-1410.7/T)) (278 K > T > 240 K) cm^2 molecule^(-1) cm^(-1). The photodissociation cross-sections are independent of pressure over the range 2 to 40 Torr. Temperature-dependent quantum yields (φ) for these transitions were obtained using integrated absorption cross-sections (∫σ_(abs)) of HNO_4 overtone vibrations measured with a FTIR spectrometer. In the atmosphere, photodissociation in the infrared is dominated by excitation of the first overtone of the OH stretching vibration (2ν_1). Inclusion of all dissociative HNO_4 overtone and combination transitions yields a daytime IR photolysis rate of approximately 1 × 10^(-5) s^(-1). This process significantly shortens the estimated lifetime of HNO_4 in the upper troposphere and lower stratosphere.

Item Type:Article
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URLURL TypeDescription
Roehl, Coleen M.0000-0001-5383-8462
Blake, Geoffrey A.0000-0003-0787-1610
Wennberg, Paul O.0000-0002-6126-3854
Additional Information:© 2002 American Chemical Society. Received: September 14, 2001; In Final Form: January 14, 2002. Publication Date (Web): March 21, 2002. This work was funded in part by NASA’s Atmospheric Effects of Aviation Program (NAG5-9307;-11157) and by The National Science Foundation (ATM-9724500; -0094670). S.A.N. thanks the Camille and Henry Dreyfus Foundation for financial support.
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Camille and Henry Dreyfus FoundationUNSPECIFIED
Issue or Number:5
Record Number:CaltechAUTHORS:20120920-075632571
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Official Citation:Photodissociation of Peroxynitric Acid in the Near-IR Coleen M. Roehl, Sergey A. Nizkorodov, Hui Zhang, Geoffrey A. Blake, and Paul O. Wennberg The Journal of Physical Chemistry A 2002 106 (15), 3766-3772
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:34252
Deposited By: Ruth Sustaita
Deposited On:20 Sep 2012 16:03
Last Modified:09 Nov 2021 23:07

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