Spectroscopic investigation of the solvation of organic molecules in superfluid helium droplets.

The spectroscopy of molecules doped into superfluid helium nanodroplets provides valuable information on the process of solvation in superfluid helium. In continuation of an earlier report on emission spectra of various phthalocyanines showing a splitting of all molecular transitions in the range of about 5-12 cm(-1), the emission spectra of tetracene, pentacene, and perylene in superfluid helium droplets are presented. The new spectra and the results obtained for the phthalocyanines are explained by an empirical model which accounts for the existence of different metastable configurations of a nonsuperfluid solvation layer around the guest molecule.