STRUCTURES OF NO3- FORMED VIA GLOW-DISCHARGE IN ATMOSPHERIC GASES

Tandem mass spectrometry experiments using both ion-molecule reactions and collision-induced dissociation (CID) in an ion trap mass spectrometer have been performed to characterize the structures of the NO3- ions that issue from an atmospheric sampling glow discharge ionization source. The experimental evidence suggests that significant abundances of at least two stable forms of NO3- can be obtained from an air-sustained glow discharge. Ab initio calculations have been performed to identify the structures of the likely isomers. Rate constants have been measured for the reaction of the less thermodynamically stable isomer(s) with carbon dioxide, and evidence is given for a new reaction, (OO-NO)- + NO2• → NO2- + O2 + NO•. The combination of em with a kinetic study is shown to be a useful approach for obtaining rate constant information when a mixture of reactive and unreactive isomers is present in the reactant population. © 1990 American Society for Mass Spectrometry.