Ultrafast photodynamics of pyrazine in the vacuum ultraviolet region studied by time-resolved photoelectron imaging using 7.8-eV pulses

Takuya Horio, Yoshi Ichi Suzuki, Toshinori Suzuki

研究成果: Contribution to journalArticle査読

13 被引用数 (Scopus)

抄録

The ultrafast electronic dynamics of pyrazine (C4N2H4) were studied by time-resolved photoelectron imaging (TRPEI) using the third (3ω, 4.7 eV) and fifth harmonics (5ω, 7.8 eV) of a femtosecond Ti:sapphire laser (ω). Although the photoionization signals due to the 5ω - 3ω and 3ω - 5ω pulse sequences overlapped near the time origin, we have successfully extracted their individual TRPEI signals using least squares fitting of the observed electron kinetic energy distributions. When the 5ω pulses preceded the 3ω pulses, the 5ω pulses predominantly excited the S4 (ππ, 1B1u+1B2u) state. The photoionization signal from the S4 state generated by the time-delayed 3ω pulses was dominated by the D3(2B2g)←S4 photoionization process and exhibited a broad electron kinetic energy distribution, which rapidly downshifted in energy within 100 fs. Also observed were the photoionization signals for the 3s, 3pz, and 3py members of the Rydberg series converging to D0(2Ag). The Rydberg signals appeared immediately within our instrumental time resolution of 27 fs, indicating that these states are directly photoexcited from the ground state or populated from S4 within 27 fs. The 3s, 3pz, and 3py states exhibited single exponential decay with lifetimes of 94 ± 2, 89 ± 2, and 58 ± 1 fs, respectively. With the reverse pulse sequence of 3ω - 5ω, the ultrafast internal conversion (IC) from S2(ππ) to S1(nπ) was observed. The decay associated spectrum of S2 exhibited multiple bands ascribed to D0, D1, and D3, in agreement with the 3ω-pump and 6ω-probe experiment described in our preceding paper [T. Horio et al., J. Chem. Phys. 145, 044306 (2016)]. The electron kinetic energy and angular distributions from S1 populated by IC from S2 are also discussed.

本文言語英語
論文番号044307
ジャーナルJournal of Chemical Physics
145
4
DOI
出版ステータス出版済み - 7 28 2016
外部発表はい

All Science Journal Classification (ASJC) codes

  • 物理学および天文学(全般)
  • 物理化学および理論化学

フィンガープリント

「Ultrafast photodynamics of pyrazine in the vacuum ultraviolet region studied by time-resolved photoelectron imaging using 7.8-eV pulses」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル