How to Interpret a Mass Spectrum Containing Ions that Undergo Rearrangement - Part 1

Rearrangement mechanisms in chemistry are fascinating, aren't they?


The McLafferty rearrangement, which may occur by a radical or an ionic mechanism, is observed in the gas chromatography-mass spectrometry (GC-MS) electron ionization (EI) during the dissociation of organic molecules containing a carbonyl-group and at least one γ-hydrogen atom, which involves a β-cleavage. For methyl esters, say, a fragment/product ion with an m/z = 74 is seen in the GC-MS EI spectrum.

Here you go - A double McLafferty (like) rearrangement!



Click to enlarge the image

M = Molecular, EE = Even-electron, OE = Odd-electron

Is the infographic easy to understand❓ Let Chemaficionado know at mychemistryhomework@gmail.com❗

References:

(1)    Wikipedia Contributors. McLafferty rearrangement. Wikipedia.
(2)    SDBS, Spectral Database for Organic Compounds, AIST. sdbs.db.aist.go.jp. https://sdbs.db.aist.go.jp/.

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