Kinetics of the reactions H + C2H4 → C2H5, H + C2H5 → 2CH3 and CH3 + C2H5 → products studied by pulse radiolysis combined with infrared diode laser spectroscopy

✍ Scribed by Alfred Sillesen; Emil Ratajczak; Palle Pagsberg

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 527 KB
• Volume: 201
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)85052-p

✦ Synopsis

Formation of methyl radicals via the consecutive reactions H+C2H,+M+C2H,+M ( I ) and H+CLH,+CH,+CH3 (?a) was initiated by pulse radiolysis of IO-100 mbar Hz in the presence of ethylene. The kinetics of CH, were studied by monitoring the transient infrared absorption at the Q( 3, 3) line of the u,=O+ 1 vibrational transition at 606. I2 cm-'. Reaction (2a) proceeds in competition with the reaction H+CZHI t MXZH,t M (2b). The methyl radicals are consumed by CHs+CH,t M+CIH, t M (3), CH,+C,H,-products (4), and H t CH,+M-CH,tM

(5). By computer simulations based on determined absolute radical yields, the observed formation and decay kinetics could be reproduced using the rate constants k2.= (7.5? 0.7) x 10" M-' s-', k2b=(l.0+0.1)~10"M-'s-',and k~=(4.0f0.2)~1O"'M-~s-'at298 Kandatotalpressureofp(H,)=lOOmbar.