Diruthenium(II,III) carboxylate compounds: Existence of both polymeric and ionic forms in solution and solid state

The reaction of Ru2Cl(mu-O2CMe)(4) and ethoxyacetic acid in methanol/water affords a compound of formula Ru2Cl(mu-O2CCH2OEt)(4) . H2O (1). The crystal structure determination of this complex shows that in the solid state [Ru-2(mu-O2CCH2OEt)(4)] exist, linked by chlorine atoms, together with cationic-anionic complexes of the type [Ru-2(mu-O2CCH2OEt)(4)(H2O)(2)](+)[Ru2Cl2O(mu-O-2 CCH2OEt)(4)](-). The reaction of 1 with OPPh3 in acetone leads to a compound with the stoichiometry Ru2Cl(mu-O2CCH2OEt)(4)(OPPh3) (2), which spectroscopic data suggest has a similar structure with cationic-anionic species together with discrete molecular units. These are the first diruthenium compounds containing three different diruthenium units with an anionic-cationic complex.