Structural characterization of Rh(III) complexes containing the polypyridyl ligands and some properties of their derivatives

The structures of the compounds [Rh(bpy)(2)(py)(Cl)](ClO4)(2) (2 . (ClO4)(2)) and [Rh(phen)(2)(py)(Cl)](ClO4)(2) (7 . (ClO4)(2)) were determined by single-crystal X-ray diffraction. Both complexes show a six-coordinate rhodium atom with two bpy or phen ligands in the cis configuration. The Rh-Cl distances are 2.334(3) and 2.323(2) Angstrom, respectively. The bond angles N-Rh-Cl formed with the axially-positioned nitrogen atom are 174.4(2) and 173.8(2)degrees. The oxidation of aquo complexes, prepared from the corresponding rhodium chloride complexes, by two equivalents of Ce(IV) in 60% HClO4 solution yields the corresponding mono-oxo products. All complexes have been identified and characterized by elemental analyses, IR, and H-1 NMR data.