The anions formed by deprotonation of heptane-, octane- and nonanedinitriles have been investigated using mass analyzed ion kinetic energy (MIKE) spectrometry with and without collisional activation. In addition, high level quantum chemical calculations have been used to model relevant parts of the potential energy surfaces. These models are in good agreement with the experimental findings. The lowest energy fragmentations are due to bond scissions initiated by intramolecular hydrogen rearrangements. The calculations show that formation of the enamine anion which is an intermediate in the Thorpe–Ziegler reaction occurs via a high barrier.