The effect of ion excitation on the formation of metastable states of D 316O and D 2F in fast charge transfer reactions

Abstract

Experimental conditions are described for optimizing the formation of metastable states of D 3 16O and D 2F in fast electron transfer reactions of their positively charged ions with sodium atoms. Changes in the ratio of metastable/dissociative states of these radicals were monitored for ion beams generated by chemical ionization of mixtures of D 2O or DF in N 2, Ar, CD 4, and D 2. Ions from N 2 reagent gas mixtures were most efficiently converted to metastables which increased in abundance sharply as the source pressure was increased. The results show that metastables are formed only from ion distributions with low internal energies. Attempts to stabilize D 3 18O were unsuccessful but the hydrate cluster, D 5 18O 2, was detected as a metastable. We explore the possibility that these radicals may be examples of vibrationally bound molecules.