Bis[(μ-iodo)iodo-η-cyclopentadienylruthenium(III)], 'CpRuI ₂' = [CpRuI₂]₂: A further example of a [CpXM(μ-X)₂MXCp] parent with cis arrangement

The very limited array of (structurally described) adducts of the form [CpMX2](2) [CpMX(mu-X)(2)MXCp] with the unsubstituted/parent Cp ( C5H5, cyclopentadienyl) ligand is augmented by a study of [CpIRu(mu-I)(2)RuICp], found to be isotypic with the recently described chloride and, with it, providing the only examples of such dimers in their 'cis' form, i.e., the terminal-X and Cp pairs to the same side of the Ru-2(mu-X)(2) arrays, which are appreciably folded at the X center dot center dot center dot X lines, with the short Ru center dot center dot center dot Ru distances (2.7748(6) (X = Cl), 2.9034(8) angstrom (X = 1)), consistent with the presence of appreciable metal-metal bonding (cf the M = Cr, X = Cl counterpart which is trans, Cr center dot center dot center dot Cr 3.3447(8) angstrom).