APPLICATION OF A SPUTTERING GLOW-DISCHARGE ION-SOURCE TO A FLOWING AFTERGLOW STUDY OF TRANSITION-METAL ION CHEMISTRY

The use of a sputtering glow discharge ion source in the study of gas phase transition metal ion chemistry under conditions where three-body processes predominate has been explored. Experiments were carried out in which the glow discharge was interfaced with a flowing afterglow r eactor in order to determine its effectiveness in the production of me tal ions with signal characteristics suitable for use in this environm ent. These initial experiments have indicated that a variety of metal ions can be formed with adequate signal-to-noise ratios. Because of th e specific instrument configuration, a mixture of helium and argon was used as the discharge gas in order to minimize noise resulting from a rgon metastables. Helium metastables produced in the discharge were qu enched by injecting argon into the flowtube immediately downstream fro m the discharge. Metal ion signals within the flowtube were observed t o stabilize approximately 10 min after initiation of the discharge, an d remained stable for the duration of subsequent analyses. Experiments in which Co+, Ni+, Cu+, and Zn+ were allowed to react with ethane wer e carried out. Overall rate constants and observed products in the rea ctions involving Ni+, Cu+ and Zn+ were consistent with those reported for ground state ions. Reaction of Co+ with CH3I indicated that a port ion of these ions was in an excited state.