Electron Induced Dissociation: A Mass Spectrometry Technique for the Structural Analysis of Trinuclear Oxo-Centred Carboxylate-Bridged Iron Complexes

We report electron induced dissociation (EID) Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry of the singly-charged cations [Fe3O(CH3COO)6]+ and [Fe3O(HCOO)6+H2O]+. Trinuclear oxo-centered carboxylate-bridged iron complexes of this type are of interest due to their electronic and magnetic properties, and because of their role as synthetic precursors of single molecule magnets. EID of these complexes is particularly efficient and provides detailed information about the triangular core, and the nature and number of ligands. EID behavior is in marked contrast to the collision induced dissociation (CID) of these species. Whereas EID allows virtually complete structural characterization, the structural information provided by CID is very limited. The results suggest that EID is particularly suitable for the structural analysis of singly-charged polynuclear metal complexes