Nitrido-ruthenium(VI) and -osmium(VI) complexes containing chelating multianionic (N, O) ligands. Synthesis, crystal structures and reactions with triphenylphosphine

摘要

A series of nitrido-ruthenium(VI) and -osmium(VI) complexes containing chelating di-, tri- and tetra-anionic ligands was synthesized by ligand substitution reaction in methanol under room conditions in the presence 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 rather insensitive to the electron-donating power of the auxiliary ligands. All the nitridoruthenium(VI) complexes react spontaneously with triphenylphosphine, 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 bearing 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. [References: 38]