Mass selected ions in solid neon: Matrix damage and site effects

Tile problems and advantages of mass-selected ion deposition in matrices ar e briefly reviewed and discussed, and initial results with our new apparatu s are reported. Both laser induced fluorescence, visible and infrared absor ption spectra of ions are detected. Using samples with natural abundance, w e demonstrate that individual isotopomers of CSS2+ can be separately de pos ited and their spectra analyzed. Our studies with halogenated benzene radic al cations indicate that deposition from the energetic beam results in matr ix damage which in turn leads to site effects and inhomogeneous broadening. Tile perturbed sites of lower symmetry have a considerable effect on. the guest spectroscopy, leading to spectral shifts and change in the spectrosco pic selection rules.