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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Real-time observation of the Woodward-Hoffmann rule for 1,3-cyclohexadiene by femtosecond soft X-ray transient absorption
| Title: | Real-time observation of the Woodward-Hoffmann rule for 1,3-cyclohexadiene by femtosecond soft X-ray transient absorption |
| Authors: | Sekikawa, Taro Browse this author →KAKEN DB | | Saito, Nariyuki Browse this author | | Kurimoto, Yutaro Browse this author | | Ishii, Nobuhisa Browse this author | | Mizuno, Tomoya Browse this author | | Kanai, Teruto Browse this author | | Itatani, Jiro Browse this author | | Saita, Kenichiro Browse this author | | Taketsugu, Tetsuya Browse this author →KAKEN DB |
| Issue Date: | 28-Mar-2023 |
| Publisher: | Royal Society of Chemistry |
| Journal Title: | Physical chemistry chemical physics |
| Volume: | 25 |
| Issue: | 12 |
| Start Page: | 8497 |
| End Page: | 8506 |
| Publisher DOI: | 10.1039/d2cp05268g |
| Abstract: | The stereochemistry of pericyclic reactions is explained by orbital symmetry conservation, referred to as the Woodward-Hoffmann (WH) rule. Although this rule has been verified using the structures of reactants and products, the temporal evolution of the orbital symmetry during the reaction has not been clarified. Herein, we used femtosecond soft X-ray transient absorption spectroscopy to elucidate the thermal pericyclic reaction of 1,3-cyclohexadiene (CHD) molecules, i.e., their isomerization to 1,3,5-hexatriene. In the present experimental scheme, the ring-opening reaction is driven by the thermal vibrational energy induced by photoexcitation to the Rydberg states at 6.2 eV and subsequent femtosecond relaxation to the ground state of CHD molecules. The direction of the ring opening, which can be conrotatory or disrotatory, was the primary focus, and the WH rule predicts the disrotatory pathway in the thermal process. We observed the shifts in K-edge absorption of the carbon atom from the 1s orbital to vacant molecular orbitals around 285 eV at a delay between 340 and 600 fs. Furthermore, a theoretical investigation predicts that the shifts depend on the molecular structures along the reaction pathways and the observed shifts in induced absorption are attributed to the structural change in the disrotatory pathway. This confirms that the orbital symmetry is dynamically conserved in the ring-opening reaction of CHD molecules as predicted using the WH rule. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/88894 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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