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 [FeI 2 L 2 ] (1; L = SC(NMe 2 ) 2 ) with KSR (R = 2,4,6-i-Pr 3 C 6 H,) yields [Fe(SR) 2 L 2 ] · PhMe (2). Oxidation of the thiolate ligands of 2 with ((Me 2 N) 2 CSSC(NMe 2 ) 2 ) 2+ affords the cationic complexes [Fe(SR)L 3 ] + and [FeL 4 ] 2+ , which were isolated as tetraphenylborate salts. A mixed ligand neutral iron sulfur cluster [Fe 4 S 4 (SR) 2 L 2 ] (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 × 10 6 pm 3 , Ζ = 4, R = 0.067. The complex exhibits C 2 -symmetry and a distorted tetrahedral coordination of Fe(II) (S–Fe–S angles between 101.7 and 125.7). The Fe–S thiourea and Fe–S thiolate 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 × 10 6 pm 3 ,Z= 1, R = 0.039. 3 shows a slightly compressed Fe 4 S 4 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.