期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 140, 期 39, 页码 12538-12544出版社
AMER CHEMICAL SOC
DOI: 10.1021/jacs.8b07155
关键词
-
资金
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-05CH11231]
- gas phase chemical physics program through the Chemical Sciences Division of Lawrence Berkeley National Laboratory
- NSF ERC, EUV Science and Technology [EEC-0310717]
- Peter Paul Ewald Fellowship from the Volkswagen Foundation
- Deutsche Forschungsgemeinschaft [SFB749]
- excellence cluster Munich-Centre for Advanced Photonics (MAP)
The ultraviolet-induced photochemistry of five-membered heterocyclic rings often involves ring opening as a prominent excited-state relaxation pathway. The identification of this particular photoinduced mechanism, however, presents a challenge for many experimental methods. We show that femtosecond X-ray transient absorption spectroscopy at the carbon K-edge (similar to 284 eV) provides core-to-valence spectral fingerprints that enable the unambiguous identification of ring-opened isomers of organic heterocycles. The unique differences in the electronic structure between a carbon atom bonded to the oxygen in the ring versus a carbon atom set free of the oxygen in the ring-opened product are readily apparent in the X-ray spectra. Ultrafast ring opening via C-O bond fission occurs within similar to 350 fs in 266-nm photoexcited furfural, as evidenced by fingerprint core (carbon 1s) electronic transitions into a nonbonding orbital of the open-chain carbene intermediate at 283.3 eV. The lack of recovery of the 1s pi* ground-state depletion in furfural at 286.4 eV indicates that internal conversion to the ground state is a minor channel. These experimental results, augmented by recent advances in the generation of isolated attosecond pulses at the carbon K-edge, will pave the way for probing ring-opened conical intersection dynamics in the future.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据