講演情報
[14p-K308-7]Time-Resolved Photoelectron Spectroscopy Combined with Theoretical Calculations: A Study on Ultrafast Ring-Opening of α-Phellandrene Stimulated by Impulsively Excited Molecular Vibrations
〇(D)Zhiyi Zhou1, Kenichiro Saita2, Yusuke Minegishi2, Tetsuya Taketsugu2,3, Taro Sekikawa1 (1.Eng. Fac., Hokudai, 2.Sci. Fac., Hokudai, 3.WPI-ICReDD, Hokudai)
キーワード：
time-resolved photoelectron spectroscopy、ring-opening reaction、ultrafast phenomenon
This study finds that the ring-opening dynamics of (-)-α-phellandrene differ significantly from the ballistic ring-opening but stepwise due to the isopropyl substituent. Time-resolved photoelectron spectroscopy (TRPES) combined with quantum chemical calculations revealed that the intramolecular vibrations impulsively stimulated by displacement excitation upon photoexcitation to Rydberg states facilitate periodic isomerization between equatorial (eq) and axial (ax) conformers with an interval of 436 fs, contributing to the ground-state ring opening. The intrinsic reaction coordinate (IRC) calculations show that the energy level of the first transition state (TS1) for αPH is high, which creates a potential barrier on the reaction pathway. This barrier might be related to the large-size isopropyl group attached to the carbon ring and leads to the hindrance of the αPH ring opening, exhibiting periodicity.