This project is in the general area of analytical and surface chemistry and in the subfield of mass spectrometry. With the support of his previous NSF grant (CHE-8406387), Professor McLafferty has developed a new technique, neutralization- reionization mass spectrometry (NRMS), with which reactive neutral gas phase species can be prepared and characterized. The goal of this experimental program is to now exploit NRMS for the fundamental study of the behavior of reactive positive and negative ions in neutralization and reionization processes and to develop analytical mass spectrometric techniques which utilize this novel approach to ion formation. The results of this research should enhance our understanding of the behavior of energetic neutral molecules which can be used in the production of new materials by plasma and beam processing techniques and could give rise to the development of new instrumentation for analytical mass spectrometry.