SSCI-VIDE+CDFA:ECI2D+CCO:EKU:ASO:PAF ; International audience ; mu-Nitrido diiron phthalocyanine [PcFe+3.5NFe+3.5Pc](0) is an efficient catalyst, able to catalyze the oxidation of methane under near-ambient conditions. In this work, we compared the properties of structurally similar mu-carbido (1), mu-nitrido (2), and mu-oxo (3) dimers of iron phthalocyanine. The goal was to discern the structural and electronic differences between these complexes and to propose a rationale for the exceptional activity of 2. Extended X-ray fine-structure spectroscopy, high-resolution X-ray emission spectroscopy, and resonant inelastic X-ray scattering were applied to study the geometry and electronic structure of iron species in the series 1-3. The data provided by core hole spectroscopies were compared to the results of DFT calculations and found to coherently describe the structural and electronic properties of 1-3 as having equivalent iron centers with formal iron oxidation degrees of 3, 3.5, and 4 for the mu-oxo, mu-nitrido, and mu-carbido dimers, respectively. However, the bond length to the bringing atom changed in an unexpected sequence Fe-O > Fe-N