posted on 2024-01-22, 15:04authored byLucia Cascino, Stefano Corni, Stefania D’Agostino
Polariton chemistry, otherwise named
molecular polaritonics, is
a very recent research field exploiting the effects of strong coupling
interaction on the chemistry of an emitter, which presents a huge
plethora of applications in life sciences, going from in vivo optostimulation
to photopharmacology. In this work, we propose for the first time
a fully atomistic computational study within the framework of time-dependent
density functional theory of a selected direction on the potential
energy surfaces of the first electronic states of an azobenzene photoswitch
interacting with a tetrahedral Ag20 nanocluster able to
sustain a localized surface plasmon in the spectral range of its isomerization
barrier. The idea is to analyze all of the effects of the plasmonic
excitation on the excited states of the molecule for the chosen isomers
in order to find out, at least for the analyzed isomerization pathway,
possible consequences of the presence of the metallic cluster. We
present a novel way to investigate the nature of collective excitations
which seems to be extremely useful in bringing to light all charge-transfer
excitations present in the photodynamics range otherwise not detectable,
these being dark modes. Charge-transfer excitations appear along the
entire transformation pathway (from trans to cis) chosen in this case;
their role is discussed. Ab initio studies like the present one open
the way for further theoretical insights as well as real technological
achievements in this promising frontier of polariton chemistry.