Chemical Application of 99Tc NMR Spectroscopy: Preparation of Novel Tc(VII) Species and Their Characterization by Multinuclear NMR Spectroscopy

Article abstract of DOI:10.1021/ja00384a007

The 99Tc NMR parameters of a number of Tc(VII) and one Tc(V) species have been determined.The anion TcO4^- (Ξ = 22.508311 MHz in H2O) was chosen as the standard for 99Tc NMR spectroscopy.A 99Tc-17O coupling constant of 131.4 Hz was obtained from a 17O- and 18O-enriched sample of TcO4^- whose 99Tc spectrum also showed an isotopic shift of 0.22 ppm/mass number arising from a statistical distribution of 16O/17O/18O isotopic isomers.Technetium-99 and proton NMR provided definitive proof for the existence of the stereochemically nonrigid TcH9^2- anion.Both TcO3F and the novel TcO3⁺ cation were synthesized and characterized by 99Tc, 17O, and 19F NMR spectroscopy.Preliminary results on two new technetium(VII) oxyfluorides tentatively identified as F2O2TcOTcO2F2 and TcO2F3 are also reported.The diamagnetic d² anion, TcO2(CN)4^3-, represents the most deshielded 99Tc environment encountered in the present study.