Solvothermal Synthesis and Characterization of the New Iron Thioantimonates(III) [Fe(C₆H₁₈N₄)]FeSbS₄ and [Fe(C₄H₁₃N₃)₂]Fe₂Sb₄S₁₀ Containing Fe^II and Fe^III and Protein‐Analogous [2Fe^III‐2S]²⁺ Clusters

Abstract

Abstract The two new compounds [Fe(tren)]FeSbS 4 ( 1 ) (tren = tris(2‐aminoethyl)amine) and [Fe(dien) 2 ]Fe 2 Sb 4 S 10 ( 2 ) (dien = diethylendiamine) were prepared under solvothermal conditions and represent the first thioantimonates(III) with iron cations integrated into the anionic network. In both compounds Fe 3+ is part of a [2Fe III ‐2S] cluster which is often found in ferredoxines. In addition, Fe 2+ ions are present which are surrounded by the organic ligands. In ( 1 ) the Fe 2+ ion is also part of the thioantimonate(III) network whereas in ( 2 ) the Fe 2+ ion is isolated. In both compounds the primary SbS 3 units are interconnected into one‐dimensional chains. The mixed‐valent character of [Fe(tren)]FeSbS 4 was unambiguously determined with Mössbauer spectroscopy. Both compounds exhibit paramagnetic behaviour and for ( 1 ) a deviation from linearity is observed due to a strong zero‐field splitting. Both compounds decompose in one single step.