The McLafferty rearrangement is a reaction observed in mass spectrometry.

He is best known for the McLafferty rearrangement reaction that was observed with mass spectrometry.

Common fragmentation processes for organic molecules are the McLafferty rearrangement and alpha cleavage.

In molecules containing carbonyl groups, alpha cleavage often competes with McLafferty rearrangement.

The certain structures favour fragmentation the α-cleavage and the McLafferty rearrangement are two examples for the often observed fragmentations.

The McLafferty rearrangement is an example of a hydrogen atom jumping to the other fragment as a part of the process of the bond breaking.

A. J. C. Nicholson (Australia) proposes a hydrogen transfer reaction that will come to be known as the McLafferty rearrangement.

During this time, he developed the first GC/MS instruments and developed techniques for determining the structure of organic molecules by mass spectrometry, most notably in the discovery of what is now known as the McLafferty rearrangement.