ON THE USE OF CO AS SCAVENGER FOR OH RADICALS IN THE OZONOLYSIS OF SIMPLE ALKENES AND ISOPRENE

The OH radical yields generated in the ozonolysis of ethene (ET), prop ene (PR), cis-2-butene (CB), trans-2-butene (TB), 2,3-dimethyl-2-buten e (TME), and isoprene (ISP) in the presence of 20 Vol.% O-2 have been determined in a darkened glass reactor at 1 bar total pressure. The hy droxyl radicals formed were scavenged by an excess of CO added to the systems. The O-2 present converted H atoms formed in this reaction int o HO2. From measurements of the increase in CO2 generation by FTIR the OH formation yields were determined to be 0.08 (ET), 0.18 (PR), 0.17 (CB), 0.24 (TB), 0.36 (TME), and 0.19 (ISP), respectively, per molecul e of reacted ozone. The combined error in the OH determinations is est imated to be < 1 0%. (C) 1997 John Wiley & Sons, Inc.