Preparation and properties of dinuclear bis[dicarbonyl(cyclopentadienyl)]diiron(II) complexes with SS coupled, dimerized sulfur-rich dithiolate ligands

Dinuclear bis[dicarbonyl(cyclopentadienyl)]diiron(II) complexes with the bridging, SS coupled, dimerized sulfur-rich dithiolate ligands, [Fe(C5H5)(CO)2(C3S5C3S5)Fe(C5H5)(CO)2] (1) and [Fe(C5H5)(CO)2(C8H4S8C8H4S8)Fe(C5H5)(CO)2] (2), were prepared by reactions of [Fe(C5H5)(CO)2I] with Na2[C3S5] or Na2[C8H4S8] [C3S52−=4,5-disulfanyl-1,3-dithiole-2-thionate(2-) and C8H4S82−=2-{(4,5-ethylenedithio)-1,3-dithiole-2-ylidene}-1,3-dithiole-4,5-dithionate(2-)] in ethanol, followed by oxidation in the air. The dinuclear structures of these complexes were established by the X-ray crystallography for 1 and by molecular weight and the electrospray mass spectra of 2. Complex 2 exhibited the (C8H4S8)2 ligand-centered oxidation at a low potential, and reacted with iodine to afford the oxidized species [Fe(C5H5)(CO)2(C8H4S8-C8H4S8)Fe(C5H5)(CO)2]Ix (x=6.0 and 10.5), of which the oxidized I10.5-species containing I3− and I5− ions exhibited electrical conductivity of 1.7×10−4 S cm−1 measured for a compacted pellet at room temperature.