Synthesis and Characterization of Neutral Hexanuclear Iron Sulfur Clusters Containing Stair-like [Fe(6)(&mgr;(3)-S)(4)(&mgr;(2)-SR)(4)] and Nest-like [Fe(6)(&mgr;(3)-S)(2)(&mgr;(2)-S)(2)(&mgr;(4)-S)(&mgr;(2)-SR)(4)] Core Structures.

The binuclear iron complex [{Fe("EtN(2)S(2)")}(2)] (1b, "EtN(2)S(2)" = N,N'-diethyl-3,7-diazanonane-1,9-dithiolate) was prepared from the free ligand and ferrous bis[bis(trimethylsilyl)amide] in toluene. In dichloromethane 1b reacts with the [Fe(4)S(4)I(4)](2-) cubane cluster to displace two iodo ligands and to form the neutral hexanuclear cluster [{Fe("EtN(2)S(2)")}(2)Fe(4)S(4)I(2)] (2), which is isolated as black crystals in 87% yield. As elucidated by an X-ray structure analysis, 2 contains the novel hexanuclear stair-like [Fe(6)(&mgr;(3)-S)(4)(&mgr;(2)-SR)(4)] core, which exhibits crystallographic inversion symmetry.