SOME EXPERIMENTS CONCERNING THE REACTIONS OF HCCO WITH C2H2, O2, NO, AND NO2

The reactions of the ketyl radical, HCCO, with C2H2 (1), O2 (2), NO (3), and NO2 (4) HCCO + C2H2 --> products (1) HCCO + O2 --> products (2) HCCO + NO --> products (3) HCCO + NO2 --> products (4) were studied at room temperature using a discharge flow system. HCCO was produced in the reaction of 0 atoms with C2H2 and detected using Far-Infrared Laser Magnetic Resonance (FIR-LMR). By following the concentration profiles of HCCO under first order conditions in the absence and presence of a large excess of the reactants, the second order rate constants of the title reactions were found to be k2 = (1.3 +/- 0.4) . 10(11), k3 = (1.3 +/- 0.4) . 10(13), and k4 = (1.6 +/- 0.4) 10(13) cm3/mol . s, respectively. For reaction (1) an upper limit of k1 less-than-or-equal-to 6 .10(9) cm3/mol . s was obtained.