The reactions of O(3P) with terminal alkenes: the H2CO channel via 3,2 H-atom shift.
The step-scan time-resolved FTIR emission spectroscopy is used to characterize systematically the H(2)CO channel for the reactions of O((3)P) with various alkenes. IR emission bands due to the products of CO, CO(2), and H(2)CO have been observed in the spectra. H(2)CO is identified to be the primary reaction product whereas CO and CO(2) are secondary reaction products of O((3)P) with alkenes. A general trend is observed in which the fraction yield of the H(2)CO product increases substantially as the reactant alkene varies from C(2)H(4), C(3)H(6), 1-C(4)H(8), iso-C(4)H(8), to 1-C(5)H(10). The formation mechanism of the H(2)CO is therefore elucidated to arise from a 3,2 H-atom shift followed by breaking of the C(1)-C(2) bond in the initially formed energized diradical RCH(2)CHCH(2)O*. The 3,2 H-atom shift may become the dominant process with the more rapid delocalization of the energy when the hydrocarbon chain of the alkene molecule is lengthened.
Su
Hongmei
H
State Key Laboratory of Molecular Reaction Dynamics, and Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China. hongmei@iccas.ac.cn
Zhao
Shaolei
S
Liu
Kunhui
K
Xiang
Tiancheng
T