Our research has also demonstrated the synthetic utility of noble-gas species for the syntheses of novel high-oxidation state transition element species. We have been able to apply noble-gas compounds to synthetic problems including high-oxidation-state transition metal chemistry., e.g., , AuF5, TcOF5, TcO2F3. This is exemplified by our contributions to Tc(VII), Re(VII) and Os(VIII) chemistry such as the syntheses and structural characterization of the TcO2F3, TcO2F4-, TcOF5, Tc2O2F9+, OsO2F3+, OsO3F+, Os2O4F7+, cis-O2Re(OTeF5)4- and Re3O6F10-. We have devoted particular attention to the little studied chemistry of Os(VIII), establishing a significant portion of what is known about Os(VIII) compounds, including the aforementioned oxide fluoride cations, fac-OsO3F3- (C3v), OsO2F5- (C2v, monocapped trigonal prism), cis-OsO4F- (C2v), OsO4F- (Cs, distorted trigonal bipyramid), and rare examples of HF coordinated to metal centers in [OsO3F][HF][SbF6] and {[OsO3F][HF]2[AsF6]}2.