Osmium complexes triflato

Salts of [OsL(NH3)5]3+ (L = pyrazine, pyrimidine, pyridazine) can be made by displacement of nitrogen from [Os(N2)(NH3)5]2+9° or from the triflato complex [0s(0S02CF3)(NH3)J]2+ and the ligands.62 Cyclic voltammetry showed reduction to the osmium(II) species, 90 and the surface-enhanced Raman spectra (SERS) of [Os(pyz)(HNH3)5]3+, [Os(pyz)(NH3)5]2+ and of their ammine-d5 derivatives were measured, as were the IR spectra.91... 

Osmium and ruthenium polypyridine complexes initially received much attention from Dwyer and coworkers because the M(II), M(III), and M(IV) oxidation states are substitution inert.Interest in them has been renewed because of their photochemical reactions and the role they play in the study of reactions of coordinated ligands " and of mixed valence ions and in the preparation of electroactive polymer films. The aqua complexes " also have important potential applications in the selective oxidation of organic molecules and water. We found that trifluoromethanesulfonato (triflato) complexes are convenient synthetic intermediates in the preparation of aqua and oxo species, " and we describe the syntheses of the cii-bis(2,2 -bipyridine) complexes here. 

The (2,2 -bipyridine-A(,A( )(2,2 6 2"-terpyridine-A(,yV, yV"),(bpy)(trpy) complexes of ruthenium and osmium, like the bis(2,2 -bipyridine-A(,N ) series, were first studied by Dwyer and coworkers " and are interesting because more than one oxidation state is substitution inert. More recently, these (bpy)(trpy) species have generated interest because the M(IV) oxo complexes are useful oxidants of organic molecules. " The (bpy)(trpy) series of complexes have also proved useful in the study of the redox chemistry of coordinated ligands. The (bpy)(trpy) and bis(bpy) complexes containing the coordinated trifluoromethanesulfonato (triflato) ligands are useful precursors to a variety of complexes. The syntheses of these species and the aqua complexes derived from them are reported here. 

These complexes are prepared by aquation of the corresponding triflato complexes that are prepared in Section C. This is readily accomplished by allowing the hygroscopic solids obtained from the triflic acid/diethyl ether solutions (before vacuum oven drying) to fully aquate in air for 1 day. Storage in a vacuum desiccator over P40,o permits the isolation of the trihydrate and dihydrate complexes for ruthenium and osmium, respectively. The yields are the same as those found for the production of the triflato complexes in Section C. 

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