Synthesis, characterization, and structural study of iron–sulfur core {Cp2Fe2(μ-SEt)2} complexes

Stepwise and Self-Assembly Synthesis of Tetranuclear Iron-Thiolate-Diisocyanide Metallocyclophane Complexes

“…The two redox processes are well separated and the potential difference of E 1/2 Red1 – E 1/2 Red2 of 2a (BF 4 ) 2 (Δ E = 0.635 V) and of 2b (BF 4 ) 2 (Δ E = 0.592 V) are attributed to strong exchange interactions between the two iron centers 2a (BF 4 ) 2 and 2b (BF 4 ) 2 propagated through the orbitals of metal–metal bond and the bridged thiolate ligands. Similar electrochemical studies with related thiolate‐bridged CpFe complexes have led to the same conclusion (Table ) …”

“…Complexes 2a (BF 4 ) 2 , 2b (BF 4 ) 2 , and 3a (BPh 4 ) 2 (BF 4 ) 2 all contain CpFe units with cis relative configurations bridged by two ethylthiolate ligands with the substituents adopting a syn orientation with respect to one another but anti with respect to the Cp ligands. The Fe–S distances in the structures of 2a (BF 4 ) 2 , 2b (BF 4 ) 2 , and 3a (BPh 4 ) 2 (BF 4 ) 2 fall in the range of 2.19–2.23 Å, values that are comparable to those of other thiolate‐bridged, Fe(III)‐containing diiron centered complexes …”

“…Chemical reagents were purchased from Aldrich Chemical Company Ltd., Lancaster Chemicals Ltd., or Fluka Ltd. All the reagents were used without further purification, apart from all solvents that were dried over Na (Et 2 O, THF) or CaH 2 (CH 2 Cl 2 , CH 3 CN) and then thoroughly degassed before use. [Cp 2 Fe 2 (μ‐SEt) 2 (NCCH 3 ) 2 ](BF 4 ) 2 ( 1 (BF 4 ) 2 ) were prepared according to the literature procedures . IR spectra were recorded on a Varian 640 FT‐IR spectrometer.…”

“…In a recent effort aimed at expanding the range of supramolecular structural motifs of tetrametallic organometallic half‐sandwich complexes and at continuing studies of dinuclear cyclopentadienyl iron thiolate‐bridged complexes and isocyanide (CNR) coordination chemistry, we investigated the use of the iron–thiolate core {Cp 2 Fe 2 (μ‐SEt) 2 } complex as a syn ligand‐directed building unit for rectangular metallomacrocycle formation. Specifically, we envisaged that this substance would self‐assemble with a linear 1,4‐diisocyanobenzene (1,4‐CNC 6 H 4 NC), which is capable of serving as a linear bridging ligand between two metal centers, to form the coordination metallomacrocycles .…”

Self-Assembly and Redox Modulation of the Cavity Size of an Unusual Rectangular Iron Thiolate Aryldiisocyanide Metallocyclophane

“…Iron thiolate core complexes have significance because they are synthetic substances that mimick the redox behavior of active sites of metalloproteins, such as hydrogenase and ferredoxins. , Among synthetic iron thiolate complexes, dinuclear cyclopentadienyliron thiolate-bridged species are perhaps the most well-studied class from the perspective of their redox crystal structural properies. − However, these substances have seldom been used as building blocks in the construction of supramolecular complex building units. In a recent effort aimed at expanding the range of supramolecular structural motifs of tetrametallic organometallic half-sandwich complexes and continuing studies of dinuclear cyclopentadienyliron thiolate-bridged complexes and isocyanide (CNR) coordination chemistry, − we have investigated use of the iron thiolate core complex {Cp 2 Fe 2 (μ-SEt) 2 } as a syn-ligand-directed building unit for rectangular metallomacrocycle formation. Specifically, we felt that this substance would self-assemble with 1,4-diisocyanobenzene (1,4-CNC 6 H 4 NC), which is capable of serving as a bridging ligand between two metal centers, to form the coordination metallomacrocycles. − Below, we describe the results of this study, which has resulted in the development of stepwise and direct self-assembly routes for construction of rectangular macrocyclic iron thiolate core complexes {Cp 2 Fe 2 (μ-SEt) 2 } bridged by 1,4-diisocyanobenzene ligands.…”