Ultrafast structural dynamics of UV photoexcited cis,cis-1,3-cyclooctadiene observed with time-resolved electron diffraction

Sri Bhavya Muvva, Yusong Liu, Pratip Chakraborty, Joao Pedro Figueira Nunes, Andrew R. Attar, Surjendu Bhattacharyya, Kurtis Borne, Elio G. Champenois, Nathan Goff, Kareem Hegazy, Matthias C. Hoffmann, Fuhao Ji, Ming-Fu Lin, Duan Luo, Lingyu Ma, Asami Odate, Shashank Pathak, Daniel Rolles, Artem Rudenko, Sajib Kumar SahaXiaozhe Shen, Xijie Wang, Matthew R. Ware, Stephen Weathersby, Peter M. Weber, Kyle J. Wilkin, Thomas J. A. Wolf, Yanwei Xiong, Xuan Xu, Jie Yang, Spiridoula Matsika, Thomas Weinacht, Martin Centurion

Research output: Contribution to journalArticlepeer-review

Abstract

Conjugated diene molecules are highly reactive upon photoexcitation and can relax through multiple reaction channels that depend on the position of the double bonds and the degree of molecular rigidity. Understanding the photoinduced dynamics of these molecules is crucial for establishing general rules governing the relaxation and product formation. Here, we investigate the femtosecond time-resolved photoinduced excited-state structural dynamics of cis,cis-1,3-cyclooctadiene, a large-flexible cyclic conjugated diene molecule, upon excitation with 200 nm using mega-electron-volt ultrafast electron diffraction and trajectory surface hopping dynamics simulations. We tracked the photoinduced structural changes from the Franck–Condon region through the conical intersection seam to the ground state. Our findings revealed a novel primary reaction coordinate involving ring distortion, where the ring stretches along one axis and compresses along the perpendicular axis. The nuclear wavepacket remains compact along this reaction coordinate until it reaches the conical intersection seam, and it rapidly spreads as it approaches the ground state, where multiple products are formed.
Original languageEnglish
Pages (from-to)471-480
Number of pages10
JournalPhysical Chemistry Chemical Physics
Volume27
Issue number1
Early online date3 Dec 2024
DOIs
Publication statusPublished - 3 Dec 2024

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