MIXED-LIGAND COMPLEXES OF RUTHENIUM(III) AND RUTHENIUM(II) WITH ETHYLENEDIAMINETETRAACETATE AND BIDENTATE PHOSPHINES AND ARSINES

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(H-2edta)(dppm)]. The complex [Ru(Hedta)(dppm)] on reduction with molecular hydrogen in dimethyl sulfoxide (dmso) gave [Ru(H-2edta)(dppm)].dmso.H2O. Reaction of K[Ru(Hedta)Cl] and [Ru(H-2edta)(H2O)] with NPr(i)(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(H-2edta)(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(H-2edta)(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.