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An investigation of the ionization processes occurring in fast atom bombardment (FAB) for perhydro-3a,6a,9a-triazaphenalene, a compound with high proton affinity/basicity and hydride donor properties

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dc.contributor.author Paul, GJC en
dc.contributor.author Rendon, T en
dc.contributor.author Anastassopoulou, J en
dc.contributor.author Theophanides, T en
dc.contributor.author Bertrand, MJ en
dc.date.accessioned 2014-03-01T01:10:48Z
dc.date.available 2014-03-01T01:10:48Z
dc.date.issued 1995 en
dc.identifier.issn 0168-1176 en
dc.identifier.uri https://dspace.lib.ntua.gr/xmlui/handle/123456789/11452
dc.subject Beam-induced ionization en
dc.subject Condensed phase en
dc.subject Fast atom bombardment en
dc.subject Hydride abstraction en
dc.subject Protonation en
dc.subject.classification Physics, Atomic, Molecular & Chemical en
dc.subject.classification Spectroscopy en
dc.subject.other ION MASS-SPECTROMETRY en
dc.subject.other GAS-PHASE BASICITIES en
dc.subject.other DEHALOGENATION REACTIONS en
dc.subject.other CHEMICAL IONIZATION en
dc.subject.other SOLUTION CHEMISTRY en
dc.subject.other CYCLIC ACETALS en
dc.subject.other REDUCTION en
dc.subject.other SPECTRA en
dc.subject.other MATRIX en
dc.subject.other FRAGMENTATION en
dc.title An investigation of the ionization processes occurring in fast atom bombardment (FAB) for perhydro-3a,6a,9a-triazaphenalene, a compound with high proton affinity/basicity and hydride donor properties en
heal.type journalArticle en
heal.identifier.primary 10.1016/0168-1176(95)04147-D en
heal.identifier.secondary http://dx.doi.org/10.1016/0168-1176(95)04147-D en
heal.language English en
heal.publicationDate 1995 en
heal.abstract The ionization processes which take place in fast atom bombardment (FAB) mass spectrometry for perhydro-3a,6a,9a-triazaphenalene, a compound with strong proton affinity/basicity and hydride donor ability, are investigated. Chemical ionization (CI) and electrospray ionization (ESI) were also performed to facilitate elucidation of the FAB ionization mechanisms. At the onset of fast atom bombardment, protonation is favored over hydride abstraction, but upon continued bombardment the intensity of [M - H](+) increases relative to [M + H](+) and hydride abstraction becomes the dominant process. In CI, protonation is strongly favored with the relative intensity of [M - H](+) much lower than that obtained in FAB. Since the reactive ionic species in CI have greater gas phase hydride ion affinities than those proposed for FAB, hydride abstraction in FAB cannot be described predominantly in gas phase terms. A condensed phase ionization model for FAB, where protonation and hydride abstraction occur in solution, can instead explain the difference in relative molecular ion intensities obtained in FAB and CI. ESI data of perhydro-3a,6a,9a-triazaphenalene further enhances the condensed phase ionization model proposed for FAB, as the negligible presence of [M - H](+) suggests that beam-induced processes are responsible for the formation of this species in FAB. This interpretation would explain the increase in relative [M - H](+) intensity upon continued fast atom bombardment, through the accumulation of beam-induced reaction products in solution. The protonation of perhydro-3a,6a,9a-triazaphenalene in FAB is also proposed to occur predominantly through beam-induced processes, as equilibrium processes in solution should not account for the absolute ion intensities obtained in FAB. The presence of a strong [M + H](+) peak in ESI of perhydro-3a,6a,9a-triazaphenalene with methanol as solvent, is thought to be a consequence of the presence of NH4+ in solution and not to reflect the predominant formation of this species in FAB through equilibrium processes in solution. ESI work with ethylene glycol as solvent supports this interpretation. en
heal.publisher ELSEVIER SCIENCE BV en
heal.journalName International Journal of Mass Spectrometry and Ion Processes en
dc.identifier.doi 10.1016/0168-1176(95)04147-D en
dc.identifier.isi ISI:A1995QV47200004 en
dc.identifier.volume 142 en
dc.identifier.issue 1-2 en
dc.identifier.spage 41 en
dc.identifier.epage 54 en


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