NITRIDO-RUTHENIUM(VI) AND NITRIDO-OSMIUM(VI) COMPLEXES CONTAINING CHELATING MULTIANIONIC (N, O) LIGANDS - SYNTHESIS, CRYSTAL-STRUCTURES ANDREACTIONS WITH TRIPHENYLPHOSPHINE

A series of nitrido-ruthenium(VI) and -osmium(VI) complexes containing chelating di-, tri- and tetra-anionic ligands was synthesized by liga nd substitution reaction in methanol under room conditions in the pres ence of 2,6-dimethylpyridine. All the newly prepared complexes are air -stable diamagnetic solids. The crystal structures of seven complexes have been established by X-ray crystallography. The Ru=N (1.615-1.594 Angstrom) and the Os=N (1.612-1.621 Angstrom) bond distances are rathe r insensitive to the electron-donating power of the auxiliary ligands. All the nitridoruthenium(VI) complexes react spontaneously with triph enylphosphine, and the intermediate [Ru-IV(N=PPh3)-L-1(py)Cl] has been isolated and characterized spectroscopically for the reaction with [( RuN)-N-VI(L-1)Cl]. However, for those nitridoruthenium(VI) complexes b earing the tri- (L-2)(3-) and tetra-anionic (L-3,L-4)(4-) ligands, the phosphiniminato-ruthenium(IV) intermediate undergoes further reaction with pyrazole to generate a bis(pyrazole)ruthenium(Iv) complex as the product.