Ortho effects in the dissociation of ionized N-chlorophenyl- and N-bromophenyl-2-aminobenzamidines: intramolecular aromatic substitution with cyclization to protonated 2-(2-aminophenyl)-1H-benzimidazoles

dc.creatorMendes, MA
dc.creatorRittner, R
dc.creatorEberlin, MN
dc.creatorSuwinski, J
dc.creatorSzczepankiewicz, W
dc.date2002
dc.date2014-07-30T18:03:46Z
dc.date2015-11-26T17:43:22Z
dc.date2014-07-30T18:03:46Z
dc.date2015-11-26T17:43:22Z
dc.date.accessioned2018-03-29T00:25:26Z
dc.date.available2018-03-29T00:25:26Z
dc.identifierEuropean Journal Of Mass Spectrometry. Im Publications, v. 8, n. 1, n. 27, n. 33, 2002.
dc.identifier1469-0667
dc.identifierWOS:000174701400004
dc.identifier10.1255/ejms.470
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/69778
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/69778
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1287572
dc.descriptionElectron ionization (70 eV) mass spectra, double-stage (MS2) 10 eV collision-induced dissociation (CID) product-ion mass spectra of molecular ions and triple-stage (MS3) sequential product-ion mass spectra of major fragment ions are reported for the parent N-phenyl and the isomeric ortho-, meta- and para-N-chlorophenyl- and N-bromophenyl-2-aminobenzamidines. Dissociation is greatly influenced by an ortho effect that favors the loss of ortho H atoms and particularly the loss of the ortho halogen substituents. Dissociation occurs via a two-step intramolecular aromatic substitution reaction and a distonic-ion intermediate inhibits scrambling of ring hydrogens thus favoring the loss of the ortho substituents. The ortho isomers form an abundant and diagnostic [M - X](+) fragment ion (X = Cl, Br) and are easily distinguished. Protonated 2-(H-1-benzimidazol-2-yl)-phenylammonium ions are likely formed; they dissociate mainly by NH3 loss upon CID and react readily with pyridine by proton transfer.
dc.description8
dc.description1
dc.description27
dc.description33
dc.languageen
dc.publisherIm Publications
dc.publisherW Sussex
dc.publisherInglaterra
dc.relationEuropean Journal Of Mass Spectrometry
dc.relationEur. J. Mass Spectrom.
dc.rightsfechado
dc.sourceWeb of Science
dc.subjectortho effect
dc.subjectbenzamidines
dc.subjectintramolecular aromatic substitution
dc.subjectpentaquadrupole mass spectrometry
dc.subjectMS/MS
dc.subjectMS/MS/MS
dc.subjectgas-phase ion chemistry
dc.subjectMass-spectrometry
dc.subjectCations
dc.titleOrtho effects in the dissociation of ionized N-chlorophenyl- and N-bromophenyl-2-aminobenzamidines: intramolecular aromatic substitution with cyclization to protonated 2-(2-aminophenyl)-1H-benzimidazoles
dc.typeArtículos de revistas


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