Fragmentation of the (cyclam-acetato)iron azide cation in the gas phase

Mass spectrometry is used to investigate the fragmentation of the ligated azidoiron cation [(cyclam-acetato)Fe(N-3)](+), which is accessible in the gas phase by electrospray ionization of a solution of its hexafluorophosphate salt in methanol/ water. Upon collisional activation, mass-selected [(cyclamacetato)Fe(N-3)](+) undergoes competing loss of dinitrogen or HN3 as the prevailing fragmentations. The former dissociation pathway is investigated in detail in order to determine whether or not the free, high-valent iron nitride [(cyclamacetato)PeN]+ is formed. The evidence obtained indeed supports the! formation of the iron nitride species as an intermediate, although the long-lived ion sampled after mass selection may also have undergone further rearrangements. (c) Wiley-VCH Verlag GmbH & Co. KGaA.