Femtosecond photoexcitation dynamics inside a quantum solvent.

ABSTRACT: The observation of chemical reactions on the time scale of the motion of electrons and nuclei has been made possible by lasers with ever shortened pulse lengths. Superfluid helium represents a special solvent that permits the synthesis of novel classes of molecules that have eluded dynamical studies so far. However, photoexcitation inside this quantum solvent triggers a pronounced response of the solvation shell, which is not well understood. Here, we present a mechanistic description of the solvent response to photoexcitation of indium (In) dopant atoms inside helium nanodroplets (HeN), obtained from femtosecond pump-probe spectroscopy and time-dependent density functional theory simulations. For the In-HeN system, part of the excited state electronic energy leads to expansion of the solvation shell within 600?fs, initiating a collective shell oscillation with a period of about 30?ps. These coupled electronic and nuclear dynamics will be superimposed on intrinsic photoinduced processes of molecular systems inside helium droplets.

SUBMITTER: Thaler B 

PROVIDER: S-EPMC6167364 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature