| 摘要 |
A ligated technetium (III/II) complex is useful as a brain perfusion imaging agent. The complex has a technetium (III/II) center surrounded by six ligating moieties. The complex preferably has a reduction potential Tc(III) to Tc(II) which is less than about +0.6 volts vs Ag/AgCl (3M NaCl) and at least low enough to be oxidized in vivo after crossing the blood brain diffusion barrier. The technetium complex has six ligating moieties, four of which use phosphorous, arsenic, or nitrogen as ligating atoms. The remaining two ligands use sulfur or selenium to complex to the Tc center. These ligands are modified to establish an effective oxidation potential of the Tc(II) thus providing the necessary redox potential for in vivo oxidation.
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