title: The influence of structural features on facile McLafferty-type, even-electron rearrangements in tandem mass spectra of carboxylate anions.
abstract: In contrast to the well-described McLafferty rearrangement in odd-electron cations, relatively little has been reported on comparable rearrangements in even-electron ions, especially negative ions. This work reports a systematic study using tandem mass spectrometry (MS/MS) fragment ion spectra of carboxylate anions having a suitably acidic proton in the gamma position. The rearrangement process was studied in both ion trap and triple quadrupole mass spectrometers; characteristic enolate anions and stable neutral products were formed at low collision energies. The process has diagnostic and analytical potential in, for example, the analysis of peptides having C-terminal serine residues and of 3-hydroxy- or 3-aminocarboxylic acids in complex mixtures.
authors.affiliation: Department of Chemistry, Dalhousie University, Halifax, NS, Canada B3H 4J3.
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Grossert
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Cook
authors.forename: Robert L
authors.initials: RL
authors.lastname: White
mesh_terms: D000179:Acrylates / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D003903:Deuterium / Q000737:chemistry; D004583:Electrons; D007553:Isotope Labeling; D011522:Protons; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D000179:Acrylates; D002264:Carboxylic Acids; D011522:Protons; D003903:Deuterium