Synthesis, characterization, and crystal structures of the osmium triflate complexes Cp∗Os(P–P)(OTf) and [Cp∗Os(P–P)(OH2)][OTf]

Treatment of the osmium(II) hydrides Cp∗Os(P–P)H (Cp∗ = pentamethylcyclopentadienyl) with methyl trifluoromethanesulfonate (MeOTf) affords osmium(II) triflate complexes with the general formula Cp∗Os(P–P)(OTf), where P–P = bis(dimethylphosphino)methane (dmpm), bis(diphenylphosphino)methane (dppm), or 1,2-bis(dimethylphosphino)ethane (dmpe). The aqua complexes [Cp∗Os(dmpm)(OH2)][OTf] and [Cp∗Os(dppm)(OH2)][OTf] are synthesized by the addition of water to the corresponding anhydrous triflates. The complexes Cp∗Os(dppm)(OTf) and [Cp∗Os(dmpm)(OH2)][OTf] have been examined crystallographically, and all compounds have been characterized by NMR spectroscopy.

Treatment of the hydride complexes Cp∗Os(P–P)H with methyl trifluoromethanesulfonate affords the triflate complexes Cp∗Os(P–P)OTf accompanied by the evolution of methane. The coordinated triflate ligand can be displaced by water to form the cationic complexes [Cp∗Os(P–P)(OH2)][OTf]. The molecular structures of the complexes Cp∗Os(dppm)OTf and [Cp∗Os(dmpm)(OH2)][OTf] are presented and discussed.Figure optionsDownload as PowerPoint slide