A coordinatively unsaturated dinuclear iron(II) complex of bulky thiolates, [(TipS)Fe(mu-SDmp)](2) (1; Tip = 2,4,6-(Pr3C6H2)-Pr-i, Dmp = 2,6-(mesityl)(2)C6H3), was synthesized from stepwise reactions of Fe{N(SiMe3)(2)}(2) with 1 equiv of HSDmp and then with 1 equiv of HSTip. Complex 1 was found to react with elemental sulfur (S-8) in toluene to generate a new class of [8Fe-7S] cluster, [(DmpS)Fe4S3](2)(mu-SDmp)(2)(mu-STip)(mu(6)-S) (2). The cluster 2 was also produced from one-pot reactions of Fe{N(SiMe3)(2)}(2) + HSDmp + HSTip + S-8 (8:6:10:7/8) and Fe-3{N(SiMe3)(2)}(2)(mu-STip)(4) + HSDmp + S-8 (8/3:16/3:7/8), where another [8Fe-7S] cluster, [(TipS)Fe4S3](2)(mu-SDmp)(2){mu-N(SiMe3)(2)}(mu(6)-S) (3), was also found as a minor byproduct. In either of the clusters, two Fe4S3 incomplete cubane units are connected by three anionic ligands, namely three thiolate S atoms for 2 or two thiolate S atoms and one amide N atom for 3, and one hexa-coordinate S atom resides at the center of the [8Fe-7S] core. They have a common Fe(II)(5)Fe(III)(3) oxidation states, and an S = (1)/(2) ground spin state was indicated by rhombic EPR signals at 10 K with g = 2.19, 2.07, and 1.96 for 2 and g = 2.13, 2.06, and 1.93 for 3. The structural relevance of clusters 2 and 3 to P-cluster, FeMo-co, and FeFe-co of nitrogenases is discussed.