A comparative study of the pyrolytic and electron impact‐induced fragmentations of 4‐phenylbutanoic acid and some analogues

Posthumus, M.A.; Nibbering, Nico M. M.; Boerboom, A.J.H.

doi:10.1002/oms.1210110902

Cited by 13 publications

(1 citation statement)

References 22 publications

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“…Essentially different fragmentation mechanisms upon pyrolysis were established as well for 4‐phenylbutanoic acid on the basis of deuterium labeling. For example, upon pyrolysis water is expelled via a 1,2‐elimination process and styrene is generated in one‐step by a 1,5‐hydrogen shift‐induced loss of enolic acetic acid, while from the molecular ion the water loss occurs via a 1,4‐elimination and the styrene ion formation via a two‐step elimination of a molecule of water and of ketene (Posthumus, Nibbering, & Boerboom, 1976; Posthumus & Nibbering, 1977b).…”

Section: Miscellaneousmentioning

confidence: 99%

Four decades of joy in mass spectrometry

Nibbering

2006

Mass Spectrometry Reviews

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Tremendous developments in mass spectrometry have taken place in the last 40 years. This holds for both the science and the instrumental revolutions in this field. In chemistry the research was heavily focused on organic molecules that upon electron ionization fragmented via complex mechanistic pathways as shown by isotopic labeling experiments. These studies, including ion structure determinations, were performed with use of double focusing mass spectrometers of both conventional and reversed geometry, and equipped with various types of metastable ion scanning and collision-induced dissociation techniques developed by physical and analytical chemists. Time-resolved mass spectrometry by use of the field ionization kinetics method, developed by physical chemists, was another powerful way to unravel details of unimolecular gas phase ion dissociations. Then the development of new ionization methods, such as desorption chemical ionization, field desorption, and fast atom bombardment permitted not only to analyze unvolatile, thermally labile and higher molecular weight compounds, but also to study their chemical behavior in the gas phase, initially with use of double focusing instruments and later on with multisector and hybrid mass spectrometers. These ionization methods also enabled to study organometallic compounds and increasingly the field of medium-sized to large biomolecules, the latter being exploded in the last decade by the development of electrospray- and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. Another area of research concerned the bimolecular chemistry of organic ions with organic molecules in the gas phase. Initially this was performed with use of among others drift-cell ion cyclotron resonance spectroscopy, that later on was replaced by the developed method of ion trapping and Fourier transform ion cyclotron resonance. Combination of the latter with the afore-mentioned ionization methods has shifted also in this case the research on organic molecules to organometallic/inorganic systems, and predominantly to biomolecules in the last decade. This invited review will describe the research efforts made by the author's group over the last 40 years together with some personal experiences during his career.

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Section: Miscellaneousmentioning

confidence: 99%

Four decades of joy in mass spectrometry

Nibbering

2006

Mass Spectrometry Reviews

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The identification of Ibuprofen and analogues in urine by pyrolysis gas chromatography mass spectrometry

Irwin

Slack

1978

Biol. Mass Spectrom.

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The pyrolysis gas chromatography mass spectrometry of Ibuprofen, Fenoprofen, Naproxen and Ketoprofen, a series of anti-inflammatory propionic acid derivatives, is shown to proceed via decarboxylation and elimination to yield characteristic ethyl and vinyl fragments. The pyrogram enables the identification of the drug to be achieved as the pure compound, in a formulated dosage form or excreted in urine. The presence of metabolites derived from Ibuprofen causes four new fragments to be observed in the urine pyrogram. The identification of 16 components of the control urine pyrogram is presented.

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Wasserstoffübertragungen, Teil 2. Radikalmechanismus der thermischen Disproportionierung des 1,2‐Dihydronaphthalins

Heesing

Müllers

1980

Chem. Ber.

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Bei der thermischen Disproportionierung von 1,2-Dihydronaphthalin (1) verlaufen Wasserstoffabspaltung und -addition als sterisch unspezifische Radikalreaktionen. Ein Synchronmechanismus2) wurde ausgeschlossen. Hydrogen Transfer Reactions, Part 2*) Radical Mechanism of Thermal Disproportionation of 1,2-DihydronaphthaleneIn the thermal disproportionation of 1,2-dihydronaphthalene (1) both hydrogen abstraction and addition are stereo-unspecific radical reactions. An electrocyclic mechanism2) was excluded.Thermische Disproportionierungen werden bei Dihydroaromaten oft gefunden, da hier das als Wasserstoffdonator wirkende Molekul unter Gewinn an Mesomerieenergie in den aromatischen Zustand iibergeht . Verschiedene Mechanismen werden diskutiert .So fand man bei der Gasphasen-Disproportionierung von 1,3-Cyclohexadien (bei ca. 300°C) einen Radikalmechani~mus~). Dagegen postulierten Gill und Hawkins') fur die thermische Disproportionierung von 1 ,2-Dihydronaphthalin (1) in Naphthalin (2) und Tetralin (3), die sie in LLisung bei ca. 300°C kinetisch verfolgten, einen konzertierten Ablauf. Eine Gruppenubertragung dieser Stereochemie ist im Grundzustand symmetrieerlaubt 'I. Wir haben dideuterierte 1,2-Dihydronaphthaline in hoher Isotopenreinheit hergestellt und mit ihrer Hilfe den Ablauf der thermischen Disproportionierung von 1 untersucht . Deuterierte AusgangsverbindungenEs wurden folgende Isotopomeres) synthetisiert:

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A comparative study of the pyrolytic and electron impact‐induced fragmentations of 4‐phenylbutanoic acid and some analogues

Cited by 13 publications

References 22 publications

Four decades of joy in mass spectrometry

Four decades of joy in mass spectrometry

The identification of Ibuprofen and analogues in urine by pyrolysis gas chromatography mass spectrometry

Wasserstoffübertragungen, Teil 2. Radikalmechanismus der thermischen Disproportionierung des 1,2‐Dihydronaphthalins

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