Determination by mass spectrometry of the structure of bisbenzoylacetoneethylenediimine and its metal chelates

Abstract

The mass spectra of bisbenzoylacetoneethylenediimine (B) and its cobalt(II), nickel(II), and copper(II) complexes have been rationalized in terms of form (II) for B in which the imino nitrogens are attached to the same carbon atoms as the methyl groups and not to the same carbon atoms as the phenyl groups, as previously proposed in the literature. Compound B is thus NN'-ethylenebis(benzoylisopropylideneimine). Novel ion-rearrangement reactions and examples of changes in metal valency in the mass spectrometer are described.