TY - JOUR
T1 - Observing the primary steps of ion solvation in helium droplets
AU - Albrechtsen, Simon H.
AU - Schouder, Constant A.
AU - Viñas Muñoz, Alberto
AU - Christensen, Jeppe K.
AU - Engelbrecht Petersen, Christian
AU - Pi, Martí
AU - Barranco, Manuel
AU - Stapelfeldt, Henrik
PY - 2023/11
Y1 - 2023/11
N2 - Solvation is a ubiquitous phenomenon in the natural sciences. At the macroscopic level, it is well understood through thermodynamics and chemical reaction kinetics
1,2. At the atomic level, the primary steps of solvation are the attraction and binding of individual molecules or atoms of a solvent to molecules or ions of a solute
1. These steps have, however, never been observed in real time. Here we instantly create a single sodium ion at the surface of a liquid helium nanodroplet
3,4, and measure the number of solvent atoms that successively attach to the ion as a function of time. We found that the binding dynamics of the first five helium atoms is well described by a Poissonian process with a binding rate of 2.0 atoms per picosecond. This rate is consistent with time-dependent density-functional-theory simulations of the solvation process. Furthermore, our measurements enable an estimate of the energy removed from the region around the sodium ion as a function of time, revealing that half of the total solvation energy is dissipated after four picoseconds. Our experimental method opens possibilities for benchmarking theoretical models of ion solvation and for time-resolved measurements of cation-molecule complex formation.
AB - Solvation is a ubiquitous phenomenon in the natural sciences. At the macroscopic level, it is well understood through thermodynamics and chemical reaction kinetics
1,2. At the atomic level, the primary steps of solvation are the attraction and binding of individual molecules or atoms of a solvent to molecules or ions of a solute
1. These steps have, however, never been observed in real time. Here we instantly create a single sodium ion at the surface of a liquid helium nanodroplet
3,4, and measure the number of solvent atoms that successively attach to the ion as a function of time. We found that the binding dynamics of the first five helium atoms is well described by a Poissonian process with a binding rate of 2.0 atoms per picosecond. This rate is consistent with time-dependent density-functional-theory simulations of the solvation process. Furthermore, our measurements enable an estimate of the energy removed from the region around the sodium ion as a function of time, revealing that half of the total solvation energy is dissipated after four picoseconds. Our experimental method opens possibilities for benchmarking theoretical models of ion solvation and for time-resolved measurements of cation-molecule complex formation.
UR - http://www.scopus.com/inward/record.url?scp=85176111492&partnerID=8YFLogxK
U2 - 10.1038/s41586-023-06593-5
DO - 10.1038/s41586-023-06593-5
M3 - Journal article
C2 - 37938709
SN - 0028-0836
VL - 623
SP - 319
EP - 323
JO - Nature
JF - Nature
IS - 7986
ER -