Vielteilchen Koinzidenzexperimente zur Untersuchung von elektronenstoßinduzierter Fragmentierung und zwischenmolekularen Energietransferprozessen in Wasser-Clustern und hydrierten Clustern aus Biomolekülen

• Antragsteller: Xueguang Ren, Ph.D.
• Fachliche Zuordnung: Physikalische Chemie von Molekülen, Flüssigkeiten und Grenzflächen, Biophysikalische Chemie ; Optik, Quantenoptik und Physik der Atome, Moleküle und Plasmen
• Förderung: Förderung von 2016 bis 2020
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 328557844

• Erstellungsjahr: 2020

Zusammenfassung der Projektergebnisse

In this project, we demonstrated a damage mechanism of biochemically relevant systems in the form of a non-local autoionizing process called intermolecular Coulombic decay (ICD). It directly involves DNA constituents or organic molecules in an aqueous environment. The products are two energetic ions and three reactive secondary electrons that can cause further damage in their vicinity. Hydrogen-bonded complexes that consist of one tetrahydrofuran (THF) moleculea surrogate of deoxyribose in the DNA backboneand one water molecule are used as a model system. After electron-impact ionization of the water molecule in the inner-valence shell the vacancy is filled by an outer-valence electron. The released energy is transferred across the hydrogen bridge and leads to ionization of the neighbouring THF molecule. This intermolecular energy transfer from water to THF is faster than the otherwise occurring intermolecular proton transfer. The signature of the ICD reaction is identified in triple-coincidence measurements of both ions and one of the final state electrons. These results could improve the understanding of radiation damage in biological tissue. Moreover, by using the hydrogen-bonded pure and mixed dimers of the heterocyclic THF molecule and water, we investigated also the role of water environment in the fragmentation of biomolecules induced by low-energy (< 100 eV) electrons. For ionization of these dimers, a molecular ring-break mechanism is observed, which is absent for the THF monomer. Employing coincident fragment ion mass and electron momentum spectroscopy, and ab initio calculations, we find that ionization of the outermost THF orbital initiates significant rearrangement of the dimer structure increasing the internal energy and leading to THF ring-break. These results demonstrate that the local environment in form of hydrogen-bonded molecules can considerably affect the stability of molecular covalent bonds.

Projektbezogene Publikationen (Auswahl)

• “Analysis of multiple scattering contributions in electron-impact ionization of molecular hydrogen”, J. Phys. B: At. Mol. Opt. Phys., 50 (2017) 204002
  Xueguang Ren, Khokon Hossen, Enliang Wang, M S Pindzola, Alexander Dorn and James Colgan
  
• “Observation of fast and slow interatomic Coulombic decay in argon dimers induced by electron-impact ionization”, Physical Review A, 96 (2017) 032715
  Xueguang Ren, Tsveta Miteva, Přemysl Kolorenč, Kirill Gokhberg, Alexander I. Kuleff, Lorenz S. Cederbaum, and Alexander Dorn
  
• “An (e, 2e+ion) study of electron-impact ionization and fragmentation of tetrafluoromethane at low energies”, Eur. Phys. J. D, 72 (2018) 43
  Khokon Hossen, Xueguang Ren, Enliang Wang, S.V.K. Kumar, and Alexander Dorn
  
• “Damaging Intermolecular Energy and Proton Transfer Processes in Alpha-Particle-Irradiated Hydrogen-Bonded Systems”, Angew. Chem. Int. Ed. 57, (2018) 17023–17027
  Shenyue Xu, Dalong Guo, Xinwen Ma, Xiaolong Zhu, Wentian Feng, Shuncheng Yan, Dongmei Zhao, Yong Gao, Shaofeng Zhang, Xueguang Ren, Yongtao Zhao, Zhongfeng Xu, Alexander Dorn, Lorenz S. Cederbaum, and Nikolai V. Kryzhevoi
  
• “Experimental evidence for ultrafast intermolecular relaxation processes in hydrated biomolecules” Nature Physics, 14 (2018) 1062–1066
  Xueguang Ren, Enliang Wang, Anna D. Skitnevskaya, Alexander B. Trofimov, Kirill Gokhberg and Alexander Dorn
  
• “Triple-differential cross sections for single ionization of CO2 by 100eV electron impact”, J. Phys. B: At. Mol. Opt. Phys., 51 (2018) 215201
  Khokon Hossen, Xueguang Ren, Enliang Wang, Maomao Gong, Xingyu Li, Song Bin Zhang, Xiangjun Chen and Alexander Dorn
  
• “Two-center interference in electron impact ionization of molecular hydrogen”, Physical Review A, 97 (2018) 022706
  Xingyu Li, Xueguang Ren, Khokon Hossen, Enliang Wang, Xiangjun Chen, and Alexander Dorn
  
• “Ultrafast Proton Transfer Dynamics on the Repulsive Potential of the Ethanol Dication: Roaming-Mediated Isomerization versus Coulomb Explosion”, Journal of Physical Chemistry A, 124 (2020) 2785-2791
  Enliang Wang, Xu Shan, Lei Chen, Thomas Pfeifer, Xiangjun Chen, Xueguang Ren and Alexander Dorn
  
• “Water acting as a catalyst for electron-driven molecular break-up of tetrahydrofuran”, Nature Communications, 11 (2020) 2194
  Enliang Wang, Xueguang Ren, WoonYong Baek, Hans Rabus, Thomas Pfeifer & Alexander Dorn