Synthesis of ruthenium complexes with planar-chiral cyclopentadienyl-pyridine or -phosphine bidentate ligands

Abstract

Novel ruthenium complexes possessing planar-chiral cyclopentadienyl-pyridine or -phosphine bidentate ligands have been synthesized from (trisubstituted cyclopentadienyl)(benzene)ruthenium complexes. Co-ordination of the pyridyl group linked to a cyclopentadienyl ring through an ester bond is fairly weak, so that the pyridine dissociates from the central ruthenium atom in acetonitrile. In contrast, the phosphine ligand tightly co-ordinates to the ruthenium even in acetonitrile. Enantiomerically pure samples of planar-chiral cyclopentadienylphosphine complexes have been prepared by use of optically pure ruthenium complexes as a starting material. The molecular structure of a neutral ruthenium dithiocarbamate complex with the cyclopentadienylphosphine bidentate ligand has been determined by X-ray crystallography.