Neutrale und kationische Eisen-Schwefel-Komplexe und -Cluster Synthese und Kristallstrukturen von [Fe(SR)2L2] · PhMe und [Fe4S4(SR)2L2] sowie zur Bildung von [Fe(SR)L3]+, [FeL4]2+, [Fe4S4(SR)L3]+ und [Fe4S4L4]2+ (R = 2,4,6-i-Pr3C6H2; L = SC(NMe2)2) / Neutral and Cationic Iron-Sulfur Complexes and Clusters Syntheses and Crystal Structures of [Fe(SR),L2] · PhMe and [Fe4S4(SR)2L2], and on the Formation of [Fe(SR)L3]+, [FeL4]2+, [Fe4S4(SR)L3]+ and [Fe4S4L4]2+ (R = 2,4,6-i-Pr3C6H2; L = SC(NMe2)2)

Abstract

The reaction of [FeI2L2] (1; L = SC(NMe2)2) with KSR (R = 2,4,6-i-Pr3C6H,) yields [Fe(SR)2L2] · PhMe (2). Oxidation of the thiolate ligands of 2 with ((Me2N)2CSSC(NMe2)2)2+ affords the cationic complexes [Fe(SR)L3]+ and [FeL4]2+, which were isolated as tetraphenylborate salts. A mixed ligand neutral iron sulfur cluster [Fe4S4(SR)2L2] (3) has been synthesized by the reaction of 2 with elemental sulfur. 3 is a precursor for cationic clusters which are obtained via the above-mentioned oxidation. The structures of 2 and 3 were determined from single crystal X-ray diffraction data. 2 crystallizes in the monoclinic space group C2/c with a = 1807.8(1), b = 1000.6(1), c = 2946.0(2) pm, β = 101.16(1), V = 5227.6 × 106 pm3, Ζ = 4, R = 0.067. The complex exhibits C2-symmetry and a distorted tetrahedral coordination of Fe(II) (S–Fe–S angles between 101.7 and 125.7). The Fe–Sthiourea and Fe–Sthiolate bond lengths were found to be 240.3(2) and 231.5(1) pm, respectively. 3: triclinic, P1, a= 1020.2(2), b = 1035.3(2), c = 1402.1(2) pm, α = 73.50(1), β = 70.47(1), γ=84.38(1),V= 1338.2 × 106pm3,Z= 1, R = 0.039. 3 shows a slightly compressed Fe4S4 core structure. The Fe– Fe distances range from 269.1 to 278.1 pm. The shortest and longest distances are observed between those Fe atoms which have two thiourea and two thiolate ligands, respectively.