Control over connectivity and magnetism of tetrahedral FeSe2 chains through coordination Fe–amine complexes

The synthesis and structural characterization is reported for [Fe(dien)2][FeSe2]2 and [Fe(tren)][FeSe2]2, two new mixed-valence compounds that contain infinite ∞1(FeSe2) tetrahedral chains separated by Fe–amine complexes. The inter- and intra-chain magnetic interactions can be controlled by changing the denticity of the amine while preserving the general structural motif.