Reduction of diruthenium(II,III) carboxylate compounds with hydroquinone: a facile preparation of diruthenium(II) complexes

The synthesis of the diruthenium(II) compounds [Ru2(μ-O2CR)4(MeOH)2] [R = Me (1), Ph (2), CMePh2 (3) C6H4-p -OMe (4), C6H4-p -CMe3 (5)] by reaction of View the MathML source[Ru2(μ-O2CR)4]+BF4- with hydroquinone, under a nitrogen atmosphere, in the presence of a base is described. This reaction constitutes an easy via to the preparation of diruthenium(II) compounds. The structure of the complexes [Ru2(μ-O2CMe)4(MeOH)2] (1) and [Ru2(μ-O2CPh)4(thf)2] (2b) is established by single crystal X-ray diffraction. These compounds show a diruthenium(II) unit bridged by four carboxylate ligands with the axial positions occupied by methanol and tetrahydrofuran molecules for 1 and 2b, respectively. Complex 1 shows, in the solid state, polymeric chains in which the molecules [Ru2(μ-O2CMe)4(MeOH)2] are linked by hydrogen bonds.