Watching a hydroperoxyalkyl radical (•QOOH) dissociate

doi:10.1126/science.abj0412

GSTDTAP > 气候变化

DOI	10.1126/science.abj0412
	Watching a hydroperoxyalkyl radical (•QOOH) dissociate
	Anne S. Hansen; Trisha Bhagde; Kevin B. Moore; Daniel R. Moberg; Ahren W. Jasper; Yuri Georgievskii; Michael F. Vansco; Stephen J. Klippenstein; Marsha I. Lester
	2021-08-06
发表期刊	Science
出版年	2021
英文摘要	Carbon-centered radicals containing the hydroperoxy group, commonly denoted as •QOOH, are elusive but are among the most critical intermediate species for kinetic modeling of hydrocarbon oxidation in various atmospheric and combustion processes. Their direct experimental observation is a long-standing challenge, with only one successful previous attempt. Using a combination of infrared activation spectroscopy and ultraviolet laser–induced fluorescence detection, Hansen et al. directly characterized the vibrational structure of a •QOOH intermediate in isobutane oxidation, collisionally stabilized and isolated, and followed its dissociative evolution under infrared activation with time and energy resolution. High-level electronic structure calculations revealed an important role of heavy-atom tunneling in this process. Science , abj0412, this issue p. [679][1] A prototypical hydroperoxyalkyl radical (•QOOH) intermediate, transiently formed in the oxidation of volatile organic compounds, was directly observed through its infrared fingerprint and energy-dependent unimolecular decay to hydroxyl radical and cyclic ether products. Direct time-domain measurements of •QOOH unimolecular dissociation rates over a wide range of energies were found to be in accord with those predicted theoretically using state-of-the-art electronic structure characterizations of the transition state barrier region. Unimolecular decay was enhanced by substantial heavy-atom tunneling involving O-O elongation and C-C-O angle contraction along the reaction pathway. Master equation modeling yielded a fully a priori prediction of the pressure-dependent thermal unimolecular dissociation rates for the •QOOH intermediate—again increased by heavy-atom tunneling—which are required for global models of atmospheric and combustion chemistry. [1]: /lookup/doi/10.1126/science.abj0412
领域	气候变化 ; 资源环境
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引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/335578
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Anne S. Hansen,Trisha Bhagde,Kevin B. Moore,等. Watching a hydroperoxyalkyl radical (•QOOH) dissociate[J]. Science,2021.
APA	Anne S. Hansen.,Trisha Bhagde.,Kevin B. Moore.,Daniel R. Moberg.,Ahren W. Jasper.,...&Marsha I. Lester.(2021).Watching a hydroperoxyalkyl radical (•QOOH) dissociate.Science.
MLA	Anne S. Hansen,et al."Watching a hydroperoxyalkyl radical (•QOOH) dissociate".Science (2021).