The FeIII azide complexes [FeIII(N3)cyclam-ac]PF6 (1⋅PF6), [FeIII(N3)Me3cyclam-ac]PF6 (2⋅PF6), and trans-[FeIII(N3)2cyclam]ClO4 (3⋅ClO4) (cyclam=1,4,8,11-tetraazacyclotetradecane; cyclam-ac=1,4,8,11-tetraazacyclotetradecane-1-acetate; Me3cyclam-ac=4,8,11-trimethyl-1,4,8,11-tetraazacyclotetra-decane-1-acetate) are studied in the gas phase with special emphasis on the formation of high-valent iron nitrides by collision-induced dissociation. Whereas the azide complex with unsubstituted cyclam-acetate 1 as major fragmentation expels N2 to form a high-valent FeV nitride complex, a similar process is not observed for its methyl-substituted congener. In contrast, loss of an azide radical results in iron reduction to FeII. Thus, the gas-phase behavior is parallel to the results obtained in spectroscopic studies of photolyzed frozen solution. The diazide complex 3 mainly fragments via consecutive losses of HN3 without change in the iron oxidation state. However, small amounts of dinitrogen loss and thus FeV nitride formation are also observed. While it is assumed that the FeV nitride complex detected by Mössbauer spectroscopy in frozen solution is still coordinated by an azide in the trans position to the nitride, both the complex [FeV(N)(N3)(cyclam)]+still bearing an intact second azide and the coordinatively unsaturated [FeV(N)(cyclam-H)]+ are observed in the gas phase.