Abstract
The technique of ion kinetic energy spectrometry has been used to observe the unimolecular decompositions of H 2O −∓ and H 2S −∓ generated by charge exchange of the corresponding high velocity positive ions. The method involves dissociative double electron capture by a high velocity ion and allows the study of unstable negative ions that may be directly observable by conventional electron capture techniques. Information on the energetics of the reaction is obtained from the kinetic energy of the product ion. The reactions under consideration are shown in (1) and (2) where X = O or S. ▪ The kinetic energy releases accompanying the reactions given in (1) and (2) have been measured and compared to those for the collision-induced reactions which produce the corresponding positive ions. The results have been used to deduce that the sequence of steps in the formation of the fragment negative ions is that given in (1) and (2). The cross section of OH − formation is observed to be somewhat greater than for O − production. This result is in contrast with dissociative electron capture cross sections from the neutral species and is interpreted on the basis of the energetic requirements for the reactions under consideration. H 2O − reacts from different electronic states in yielding OH − on the one hand and O − on the other. The energy partitioning associated with reaction (2) suggests that the neutral productions 2H' rather than H 2. The kinetic energy losses accompanying excitation and kinetic energy releases upon fragmentation were similar for the corresponding reactions of the sulfur and oxygen-containing ions indicating related mechanisms in the two sets of reactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.