Transformation of an [Fe(η²‐N₂H₃)]⁺Species to π‐Delocalized [Fe₂(μ‐N₂H₂)]2+/+Complexes

Diiron diazenes: A monomeric Fe(η2-N2H3) species has been prepared, and exposure to oxygen yields a diiron complex that features five-coordinate iron centers and an activated bridging diazene ligand (see picture; C gray, N blue, Fe black, P red, O green). Structural, theoretical, and spectroscopic data for the redox pair [Fe2(μ-N2H2)]2+/+ are consistent with 4-center, 4-electron π-delocalized bonding across the Fe-NH-NH-Fe core that finds analogy in butadiene and the butadiene anion. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.