Attosecond spectroscopy reveals secrets of electron movement in molecules
A study recently published in Nature Chemistry answers one of the most fascinating questions in chemistry: how long does it take for an electron to initiate charge transfer in molecules?
An international team composed of researchers from the Politecnico di Milano, the National Research Council of Italy, the Universidad Autónoma de Madrid, the Universidad Complutense de Madrid, and the Elettra Sincrotrone Trieste has captured the first moments of charge transfer in a molecule following interaction with attosecond pulses. The scientists measured the time it takes for an electron to move from an atom to an adjacent chemical bond and observed the structural changes in the molecule during this ultrafast time interval.
This work is the result of the TOMATTO European project, funded by a prestigious ERC Synergy Grant.
In nature, photosynthesis powers plants and bacteria, while in photovoltaic panels, sunlight is converted into electrical energy. All these processes are driven by the movement of electrons and involve charge transfer at the molecular level. The redistribution of electron density in molecules after they absorb light is an ultrafast phenomenon of great importance, involving quantum effects and molecular dynamics.
The ability to measure these dynamics with extreme temporal precision not only unveils the secrets of physical processes but also opens new avenues for 'designing' molecules capable of controlling and enhancing these effects.
Rocío Borrego Varillas, Cnr-Ifn researcher
Scientists have revealed new secrets of the ultrafast dynamics of molecules through the use of attosecond pulses. This research sheds new light on the fascinating dance between electrons and nuclei in technologically relevant molecules, bringing our understanding of chemical processes to an entirely new level.
It has been discovered that electron transfer from the donor amine group occurs in less than 10 femtoseconds (i.e., 10⁻¹⁴ seconds). This transfer is accompanied by a synchronized movement of nuclei and electrons. Subsequently, a relaxation process unfolds on a timescale of less than 30 femtoseconds.
This study not only unveils the mysteries of ultrafast dynamics in molecules but also lays the groundwork for future research in the field, opening the doors to incredible advancements, both in theory and in the practical applications of attosecond science.
Mauro Nisoli, Professor of the Department of Physics
Vismarra, F., Fernández-Villoria, F., Mocci, D. et al.
Few-femtosecond electron transfer dynamics in photoionized donor–π–acceptor molecules.
Nat. Chem. (2024).
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