Cross‐Linked Layered Structure of Magnetically Ordered [Fe(TCNE)₂]⋅z CH₂Cl₂ Determined by Rietveld Refinement of Synchrotron Powder Diffraction Data

The wages of spin: Insight into the elusive structure of [V(TCNE)x]-based magnets is provided by the structural analysis of the title compound (Tc≈100 K; TCNE=tetracyanoethylene; z≈0.3), in which {FeII(μ4-[TCNE]).−} layers are bridged by diamagnetic TCNE dimers μ4-[C4(CN)8]2− (see picture; Fe gold; C black; N blue). Strong intralayer spin coupling between the FeII centers leads to the observed magnetic ordering.