Intersystem Crossing of 2-Methlypyrazine Studied by Femtosecond Photoelectron Imaging

Naipisai Wumaierjiang; Bumaliya Abulimiti; Fengzi Ling; Mei Xiang; Xulan Deng; Jie Wei; Bing Zhang

doi:10.3390/molecules27196245

Intersystem Crossing of 2-Methlypyrazine Studied by Femtosecond Photoelectron Imaging

Molecules. 2022 Sep 22;27(19):6245. doi: 10.3390/molecules27196245.

Authors

Naipisai Wumaierjiang¹, Bumaliya Abulimiti^{1

2}, Fengzi Ling², Mei Xiang^{1

2}, Xulan Deng², Jie Wei², Bing Zhang²

Affiliations

¹ Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional Materials, School of Physics and Electronic Engineering, Xinjiang Normal University, Urumqi 830054, China.
² State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.

Abstract

2-methylpyrazine was excited to the high vibrational dynamics of the S₁ state with 260 nm femtosecond laser light, and the evolution of the excited state was probed with 400 nm light. Because it was unstable, the S₁ state decayed via intersystem crossing to the triplet state T₁, and it may have decayed to the ground state S₀ via internal conversion. S₁-to-T₁ intersystem crossing was observed by combining time-resolved mass spectrometry and time-resolved photoelectron spectroscopy. The crossover time scale was 23 ps. Rydberg states were identified, and the photoelectron spectral and angular distributions indicated accidental resonances of the S₁ and T₁ states with the 3s and 3p Rydberg states, respectively, during ionization.

Keywords: intersystem crossing; methylpyrazine; photoelectron imaging; pump–probe; time-resolved spectroscopy.

MeSH terms

Diagnostic Imaging
Lasers
Photoelectron Spectroscopy
Quantum Theory*
Vibration*

Grants and funding

This work was supported by the Xinjiang Autonomous Region Outstanding Youth Fund Project (2022D01E12), the National Natural Science Foundation of China (No. 21763027), the Innovation Team for Monitoring of Emerging Contaminants and Biomarkers (2021D14017), the Xinjiang Graduate Education and Teaching Reform Project (No. XJ2021GY25), the Xinjiang Regional Collaborative Innovation Project (No. 2019E0223), the Undergraduate Teaching Research and Reform Project of Xinjiang Normal University (No. SDJG2021-12), the Scientific Research Program of Colleges and Universities in Xinjiang (No. XJEDU2020Y029), and the “13th Five-Year” Plan for the Key Discipline Physics Bidding Project of Xinjiang Normal University (No. 17SDKD0602). All of the above funding programs are thanked for their support.