Formative period in the x-ray-induced photodissociation of organic molecules

E. Kukk, H. Fukuzawa, J. Niskanen, K. Nagaya, K. Kooser, D. You, J. Peschel, S. Maclot, A. Niozu, S. Saito, Y. Luo, E. Pelimanni, E. Itälä, J. D. Bozek, T Takanashi, M. Berholts, P. Johnsson, K. Ueda

Research output: Contribution to journalArticlepeer-review


Absorption of x-ray photons by atomic inner shells of light-element organics and biomolecules often leads to formation of dicationic electronic states and to molecular fragmentation. We investigated the x-ray-induced dissociation landscape of a representative medium-sized organic molecule, thiophene, by femtosecond x-ray pulses from the Super Photon Ring-8 GeV (SPring-8) Angstrom Compact Free-Electron Laser (SACLA). Holes, created in the sulfur 2p orbital by photoemission, were filled by the Auger process that created dicationic molecular states within a broad range of internal energies—a starting point particular to x-ray-induced dynamics. The evolution of the ionized molecules was monitored by a pump-probe experiment using a near-infrared (800 nm) laser pulse. Ion-ion coincidence and ion momentum analysis reveals enhanced yields of ionic fragments from multibody breakup of the ring, attributed to additional ionization of the highly excited fraction of the dicationic parent molecular states. The transient nature of the enhancement and its decay with about a 160-fs time constant indicate formation of an open-ring parent geometry and the statistical survival time of the parent species before the dissociation events. By probing specific Auger final states of transient, highly excited nature by near-infrared light, we demonstrate how pump-probe signatures can be related to the key features in dynamics during the early period of the x-ray-induced damage of organic molecules and biomolecules.
Original languageEnglish
Article number013221
Number of pages12
JournalPhysical Review Research
Issue number1
Publication statusPublished - 2021

Subject classification (UKÄ)

  • Atom and Molecular Physics and Optics


Dive into the research topics of 'Formative period in the x-ray-induced photodissociation of organic molecules'. Together they form a unique fingerprint.

Cite this