Capturing roaming molecular fragments in real time

doi:10.1126/science.abc2960

GSTDTAP > 气候变化

DOI	10.1126/science.abc2960
	Capturing roaming molecular fragments in real time
	Tomoyuki Endo; Simon P. Neville; Vincent Wanie; Samuel Beaulieu; Chen Qu; Jude Deschamps; Philippe Lassonde; Bruno E. Schmidt; Hikaru Fujise; Mizuho Fushitani; Akiyoshi Hishikawa; Paul L. Houston; Joel M. Bowman; Michael S. Schuurman; François Légaré; Heide Ibrahim
	2020-11-27
发表期刊	Science
出版年	2020
英文摘要	Roaming is distinct from conventional reaction channels because of the unusual geometries that chemical systems use to bypass the minimum energy pathway. It is a relatively new phenomenon that is usually determined in experiments through spectroscopic characterization of the roaming products. Using a combination of time-resolved Coulomb explosion imaging and quasiclassical trajectory analysis, Endo et al. report real-time observation of individual fragments of the prototypical reaction of deuterated formaldehyde (D2CO) dissociation as they roam on ultrafast time scales. They show that roaming not only occurs several orders of magnitude earlier than previously expected but also that it can terminate in a radical (D + DCO) rather than the well-known molecular (D2 + CO) product channel. Science , this issue p. [1072][1] Since the discovery of roaming as an alternative molecular dissociation pathway in formaldehyde (H2CO), it has been indirectly observed in numerous molecules. The phenomenon describes a frustrated dissociation with fragments roaming at relatively large interatomic distances rather than following conventional transition-state dissociation; incipient radicals from the parent molecule self-react to form molecular products. Roaming has been identified spectroscopically through static product channel–resolved measurements, but not in real-time observations of the roaming fragment itself. Using time-resolved Coulomb explosion imaging (CEI), we directly imaged individual “roamers” on ultrafast time scales in the prototypical formaldehyde dissociation reaction. Using high-level first-principles simulations of all critical experimental steps, distinctive roaming signatures were identified. These were rendered observable by extracting rare stochastic events out of an overwhelming background using the highly sensitive CEI method. [1]: /lookup/doi/10.1126/science.abc2960
领域	气候变化 ; 资源环境
URL	查看原文
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/304880
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Tomoyuki Endo,Simon P. Neville,Vincent Wanie,et al. Capturing roaming molecular fragments in real time[J]. Science,2020.
APA	Tomoyuki Endo.,Simon P. Neville.,Vincent Wanie.,Samuel Beaulieu.,Chen Qu.,...&Heide Ibrahim.(2020).Capturing roaming molecular fragments in real time.Science.
MLA	Tomoyuki Endo,et al."Capturing roaming molecular fragments in real time".Science (2020).