The UV Photoinduced Ring-Closing Reaction of Cyclopentadiene Probed with Ultrafast Electron Diffraction

作者：J. Lederer, Lauren Bertram, Lisa Huang, Surjendu Bhattacharyya, Sébastien Boutet, Xinxin Cheng, Stuart W. Crane, R. J. England, Martin Graßl, Lauren Heald, Fuhao Ji, Patrick Krämer, Huynh Van Sa Lam, Kirk A. Larsen, Cuong Le, Ming‐Fu Lin, Yusong Liu, Kenneth A. Lopata, Mike Minitti, Sri Bhavya Muvva, J. Pedro F. Nunes, Zane Phelps, Sharon S. Philip, Krishna Khakurel, Alexander H. Reid, Daniel Rolles, Artem Rudenko, Sajib Kumar Saha, John S. Searles, Xiaozhe Shen, Jiayue Wang, Stephen Weathersby, Peter M. Weber, Thomas Wolf, Yanwei Xiong, T. Xu, Jie Yang, Longteng Yun, Haoran Zhao, Adam Kirrander, Martin Centurion · 发表于：The Journal of Physical Chemistry A · 年份：2025 · DOI：10.1021/acs.jpca.5c05681 · 被引用次数：2 · 研究领域：Chemical Reactions and Mechanisms、Advanced Chemical Physics Studies、Cyclization and Aryne Chemistry

Conjugated cyclic organic molecules are common across many fields such as pharmaceuticals, are naturally occurring in biological systems, and are used in synthetic materials. One particular area of interest from a photochemical point of view is the formation of highly strained cyclic organics. We investigate the photoinduced reaction of cyclopentadiene, a five-membered organic ring molecule, which can form strained three and four carbon rings after photoexcitation with UV light, with the gas-phase ultrafast electron diffraction instrument at the SLAC MeV-UED facility. Electron diffraction offers a direct probe sensitive to the nuclear geometry during the reaction, allowing for the determination of the distribution of products formed following photoexcitation. We observe the simultaneous formation of the highly strained ring-closed bicyclo[2.1.0]pentene and vibrationally hot cyclopentadiene within the temporal resolution of the experiment and determine the relative yield of all reaction products. The experimental results are in good agreement with the predictions of trajectory simulations.