Cyclic Tetranuclear Iron-Carbonyl Complex Containing Thiobisbenzenethiolate Ligands: Synthesis and Structural Characterization
A new macromolecular double-butterfly Fe/S carbonyl cluster, [Fe2(CO)6]2(μ-4,4′-thiobisbenzenethiolato)2 (1), a model for the active site of [Fe-Fe] hydrogenases, has been prepared and characterized by spectroscopic methods and X-ray crystallography. The molecular structure of 1 contains two units of S2Fe2(CO)6 covalently linked to two thiobisbenzene groups to form a 26-membered metallocycle with the benzene substituents on sulfur adopting an ae stereochemistry. The Fe-Fe bond in 1 is 2.5046(5) Å which is close to that of the enzyme and related complexes. Crystals of 1 obtained from dichlormethane solution of [Fe2(CO)6]2(μ-4,4′-thiobisbenzenethiolato)2 contain two dichloromethane molecules trapped in the cavity of 1. Infrared spectrum of 1 has peaks at 2071, 2030, and 1972 cm⁻¹ charateristic of the presence of the Fe2(CO)6 core. Spectroscopic evidence suggest significant electronic interaction between the thiobisbenzene moieties and the S2Fe2(CO)6 units in 1.
Inorganica Chimica Acta
Johnson, Shakeena L.; Gerasimchuk, Nikolay N.; and Mebi, Charles A., "Cyclic Tetranuclear Iron-Carbonyl Complex Containing Thiobisbenzenethiolate Ligands: Synthesis and Structural Characterization" (2018). Faculty Publications - Physical Sciences. 26.