01.12.20 - IRTG Seminar: Rebecca Boll "Coulomb explosion imaging of complex single molecules at European XFEL"
SQS Group, European XFEL
| When |
Dec 01, 2020
from 06:00 PM to 07:00 PM |
|---|---|
| Where | Webinar via zoom |
| Contact Name | Simone Ortolf |
| Contact Phone | 97666 |
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Coulomb explosion imaging of complex single molecules at European XFEL
Recording images of individual molecules with ultrashort exposure times has been a long-standing dream in molecular physics, chemistry, and biology, because this would allow one to follow the motion of atoms on their inherent timescale. It was also among the main driving forces for the development of X-ray free-electron lasers.
In one of the first user experiments at the Small Quantum Systems (SQS) instrument, using the reaction microscope (REMI) user end station, we employed the very intense, femtosecond soft X-ray pulses from the European XFEL to record snapshot images of the complete structure of a complex molecule with eleven atoms, including all hydrogens, by Coulomb explosion imaging. The intriguingly clear momentum images allow us to identify each atom’s position in the molecule unambiguously, and to trace the rearrangement of charge within the molecule.
By combining our experimental results with state-of-the-art molecular dynamics calculations, we are able to follow in detail the charge-up dynamics of the molecule throughout the femtosecond X-ray pulse, thus gaining unprecedentedly detailed insights into the ultrafast charge rearrangement and fragmentation dynamics. The sensitivity of the fragmentation pattern to the molecular structure at the instant of ionization, in combination with the femtosecond pulse duration holds the promise of monitoring the temporal evolution of the molecular structure with this method in a time-resolved experiment. Together with the prospect of even higher repetition rates at upcoming continuous FELs, this brings the dream of recording molecular movies of photochemical reactions very close to realization.
Recording images of individual molecules with ultrashort exposure times has been a long-standing dream in molecular physics, chemistry, and biology, because this would allow one to follow the motion of atoms on their inherent timescale. It was also among the main driving forces for the development of X-ray free-electron lasers.
In one of the first user experiments at the Small Quantum Systems (SQS) instrument, using the reaction microscope (REMI) user end station, we employed the very intense, femtosecond soft X-ray pulses from the European XFEL to record snapshot images of the complete structure of a complex molecule with eleven atoms, including all hydrogens, by Coulomb explosion imaging. The intriguingly clear momentum images allow us to identify each atom’s position in the molecule unambiguously, and to trace the rearrangement of charge within the molecule.
By combining our experimental results with state-of-the-art molecular dynamics calculations, we are able to follow in detail the charge-up dynamics of the molecule throughout the femtosecond X-ray pulse, thus gaining unprecedentedly detailed insights into the ultrafast charge rearrangement and fragmentation dynamics. The sensitivity of the fragmentation pattern to the molecular structure at the instant of ionization, in combination with the femtosecond pulse duration holds the promise of monitoring the temporal evolution of the molecular structure with this method in a time-resolved experiment. Together with the prospect of even higher repetition rates at upcoming continuous FELs, this brings the dream of recording molecular movies of photochemical reactions very close to realization.
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