Mixed-ligand complexes of ruthenium-(III) and -(II) with ethylenediaminetetraacetate and bidentate phosphines and arsines

Abstract

Interaction of K[Ru(Hedta)Cl]·2H₂O and [Ru(Hedta)(H₂O)](edta = ethylenediaminetetraacetate) with bis(diphenylphosphino)methane (dppm) in water–ethanol mixture produces [Ru(Hedta)(dppm)] and [Ru(H₂edta)(dppm)]. The complex [Ru(Hedta)(dppm)] on reduction with molecular hydrogen in dimethyl sulfoxide (dmso) gave [Ru(H₂edta)(dppm)]·dmso·H₂O. Reaction of K[Ru(Hedta)Cl] and [Ru(H₂edta)(H₂O)] with NPrⁱ(PPh₂)₂, 1,2-bis(diphenylphosphino)ethane (dppe) and 1,2-bis(diphenylarsino)ethane (dpae) gave mononuclear complexes of general formulae [Ru(Hedta)(L–L)] and [Ru(H₂edta)(L–L)] which present a combination of hard and soft donor atoms in the co-ordination sphere. All these complexes were characterized by physicochemical studies. The X-ray crystallographic study of [Ru(H₂edta)(dppm)]·dmso·H₂O reveals that the co-ordination sites of the distorted ruthenium(II) octahedron are occupied by the tetradentate edta and dppm which binds as a bidentate moiety with a four-membered chelate ring having each phosphorus trans to the nitrogen atoms of the ethylenediamine collar. Hydrogens of the two protonated free carboxyl groups of the edta moiety and the water molecule take part in an extensive hydrogen-bonding network.