Kinetics of the reactions of OH radicals with 2-methoxy-6-(trifluoromethyl)pyridine, diethylamine, and 1,1,3,3,3-pentamethyldisiloxan-1-ol at 298 ± 2 K

✍ Scribed by Ernesto C. Tuazon; Pilar Martin; Sara M. Aschmann; Janet Arey; Roger Atkinson

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 370 KB
• Volume: 43
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20594

✦ Synopsis

Abstract

Rate constants for the reactions of 2‐methoxy‐6‐(trifluoromethyl)pyridine, diethylamine, and 1,1,3,3,3‐pentamethyldisiloxan‐1‐ol with OH radicals have been measured at 298 ± 2 K using a relative rate method. The measured rate constants (cm^3^ molecule^−1^ s^−1^) are (1.54 ± 0.21) × 10^−12^ for 2‐methoxy‐6‐(trifluoromethyl)pyridine, (1.19 ± 0.25) × 10^−10^ for diethylamine, and (1.76 ± 0.38) × 10^−12^ for 1,1,3,3,3‐pentamethyldisiloxan‐1‐ol, where the indicated errors are the estimated overall uncertainties including those in the rate constants for the reference compounds. No reaction of 2‐methoxy‐6‐(trifluoromethyl)pyridine with gaseous nitric acid was observed, and an upper limit to the rate constant for the reaction of 1,1,3,3,3‐pentamethyldisiloxan‐1‐ol with O~3~ of <7 × 10^− 20^ cm^3^ molecule^−1^ s^−1^ was determined. Using a 12‐h average daytime OH radical concentration of 2 × 10^6^ molecule cm^−3^, the lifetimes of the volatile organic compounds studied here with respect to reaction with OH radicals are 7.5 days for 2‐methoxy‐6‐(trifluoromethyl)pyridine, 1.2 h for diethylamine, and 6.6 days for 1,1,3,3,3‐pentamethyldisiloxan‐1‐ol. Likely reaction mechanisms are discussed. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 631–638, 2011