Program:                                                                                                                           
15:00-15:15       Coffee & cake in the foyer
15:15-16:00       Scientific talk in Auditorium I

Speaker: Prof. Henrik Stapelfeldt, Aarhus University

Abstract:

Solvation is an omnipresent process both in our daily life and in the natural sciences. At the atomic level, the primary steps of solvation are the attraction and binding of ions or molecules of a solute to molecules or atoms of a solvent. Hitherto, these steps have not been observed in real time.

I will present recent experimental results that have enabled us to observe the solvation dynamics of a single alkali cation ion in liquid helium with atomic resolution and on the natural femtosecond time scale. A single Na⁺ is created instantly at the surface of a liquid He nanodroplet and we measured in real time the gradual attachment of individual He atoms to the ion.  In addition, we determined how fast the solvent-solute binding energy is dissipated from the local region around the alkali ion [1].

[1]    S. H. Albrechtsen, C. A. Schouder, A. Viñas Muñoz, J. K. Christensen, C. Engelbrecht Petersen, M. Pi, M. Barranco and H. Stapelfeldt, Nature 623, 319 (2023)