Abstract
A laser spectroscopic and mass spectrometric study of ionic and molecular clusters of biological interest is reported. The molecules of interest and their aggregates were generated in a supersonic beam and analyzed by mass resolved resonant two photon absorption and ionization (R2PI) and by collision induced mass spectrometry (CID-MS). The absence of the solvent allows to study these systems in the isolated state free of undesired solvent effects which may level off the differences in their properties. The gas phase results have been compared to theoretical estimates of the structure and stability of the systems under investigation.