Rate coefficients for the reaction of OH with Cl2, Br2, and I2 from 235 to 354 K

✍ Scribed by M. K. Gilles; J. B. Burkholder; A. R. Ravishankara

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 159 KB
• Volume: 31
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1999)31:6<417::aid-kin3>3.0.co;2-a

✦ Synopsis

Rate coefficients for the reaction of OH with Cl 2 , (k 1 ), Br 2 , (k 2 ) and I 2 , (k 3 ), were measured under pseudo-first-order conditions in OH. OH was produced by pulsed laser photolysis of H 2 O 2 (or HNO 3 ) and its temporal profile was monitored by laser-induced fluorescence. The measured rate coefficients for k 1 (231-354 K) and k 2 (235-357 K) are:

k 2 (T) ϭ (1.98 Ϯ 0.51) ϫ 10 Ϫ11 exp[(238 Ϯ 70)/T] cm 3 molecule Ϫ1 s Ϫ1 k 3 was independent of temperature between 240 and 348 K with an average value of (2.10 Ϯ 0.60) ϫ 10 Ϫ10 cm 3 molecule Ϫ1 s Ϫ1 . The quoted uncertainties are 2 (95% confidence limits, 1 A ϭ A lnA ) and include estimated systematic errors. Our measurements significantly improve the accuracy of k 1 . This is the first report of a slight negative temperature dependence for k 2 and of the temperature independence of k 3 .