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

Paul, GJC; Rendon, T; Anastassopoulou, J; Theophanides, T; Bertrand, MJ

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