The fragmentation behavior and fragment stability in the gas phase after electron impact was measured by EI-MS. These measurements demonstrated notable similarities for compounds ßI and ßII as well as for ßIII and ßIV. The representative spectra can be found in the SI. Table shows selected peaks with their respective intensities and suggested fragments. In general, all the ß-ketoiminates exhibit no significant higher m/z ratio than their respective mononuclear molecular ion peak, which were present with much higher intensities (86 %-100 %) as for the respective all-nitrogen coordinated compounds targeted in this study.