The CH2CHO + O channel of the reaction of vinyl radical with O2

The reaction kinetics of C2H3 + O2 has been studied at room temperature, where, CH2CHO produced in this reaction is monitored quantitatively by using a laser induced fluorescence technique. The reaction rate constant is obtained as (8.5 ± 1.0) × 10−12 cm3 molecule−1 s−1 with almost no pressure dependence for the range of 10–100 Torr (He): the present result is consistent with the previous experimental studies. Also by using two different precursors as a source of C2H3, the branching fraction of producing CH2CHO + O channel is determined as ϕ(CH2CHO) = 0.14–0.21, i.e., O–O bond scission in the reaction intermediate, vinylperoxy radical, is confirmed, exhibiting clear contrast to alkylperoxy radicals.