Synthesis of [2Fe-2S] and [4Fe-4S] clusters having terminal amide ligands from an iron(II) amide complex

The reaction of iron(II) bis-amide Fe{N(SiMe3)(2)}(2) with elemental sulfur afforded a direct entry to new [FC2S2] and [Fe4S4] clusters with terminal amide groups, Fe4S4(N(SiMe3)214 (1) and Fe2S2{N(SiMe3)(2)}(2)(tmtu)(2) (2), whose structures have been determined by X-ray crystallography. Tetrameric cubane cluster 1 exhibits one reversible and one quasireversible processes in the cyclic voltammetry, whereas dimeric rhombus complex 2 reveals one irreversible reduction process.