SOLVATION OF HCl, AGGREGATION OF H$_2$O, HCl AND THEIR DEUTERATED ISOTOPES IN SUPERFLUID He DROPLETS}

Abstract

this work was supported by FOR 618 of the German Science FoundationAuthor Institution: Department of Physical Chemistry II; Ruhr-University Bochum, Universitatsstr. 150, D-44780We investigate aggregates of HCl, H$_2$O and their deuterated isotopes embedded in superfluid helium using a helium nanodroplet spectrometer combined with a cw infrared OPO set up with an output power of up to 2.7 W and a resolution of better than 0.001 cm$^{-1}$. Depletion spectra of the super cooled aggregates (0.37 K) were recorded between 2650 cm$^{-1}$ and 2720 cm$^{-1}$. We were able to assign the HCl stretch vibration of the HCl-H$_2$O complex. We also observed spectral features of (HCl)$_m$(H$_2$O)$_n$ aggregates and isotopes in the region of the H$_3$O$^+$ stretch vibration. The question of how many H$_2$O molecules are needed to solvate HCl will be addressed