UV absorption spectra, kinetics and mechanism for alkyl and alkyl peroxy radicals originating from t-butyl alcohol

✍ Scribed by Sarka Langer; Evert Ljungström; Jens Sehested; Ole J. Nielsen

• Book ID: 103030379
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 499 KB
• Volume: 226
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(94)00691-1

✦ Synopsis

Alkyl and alkyl peroxy radicals from t-butyl alcohol (TBA), HOC(CH,),CH; and HOC(CH9)&H20i have been studied in the gas phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectra and kinetics, and long path-length Fourier transform infrared spectroscopy (FTIR) to identify and quantify the reaction products. Absorption cross sections were quantified over the wavelength range 220-320 nm. At 240 nm, ~~~~~"~,~~=(2.4fO.3)~ lo-" and ~~HOC(CH1j2CH202= (3.4f0.5) x 1O-18 cm2 molecule-' have been obtained. Observed rate constants for the self-reaction of HOC(CH3)2CH;

and HOC(CH3)2CH20i radicals were found to be (3.0+0.5)x10-" and (7.8f 1.5)X lo-i2 cm3 molecule-' s-i, respectively. For the reaction of the alkyl radical with O2 in 1 atm SFs a rate constant of (1.8f0.2) x lo-i2 cm3 molecule-' s-' was found. k(HOC(CH,),CH,O; +NO) and k(HOC(CH3)2CH20i +NO1) were determined to be (4.9kO.9) x 10-i* and (6.7f0.9) x lo-l2 cm3 molecule-' s-', respectively. In the FTIR experiments products were studied using chlorine-initiated oxidation in TBA/N2/Q and TBA/N2/02/C12 mixtures.