Novel TcVO(III) N2S2 complexes: interconversion by redox reaction.

To improve the versatility of ligands suitable for complexing a TcVO center core, a new bisaminoethanethiol (BAT) ligand, 7, was synthesized. A neutral and stable complex, [99mTc]7 (reduced), was initially formed. The reduced form of the Tc-99m complex can be converted to the oxidized form, and vice versa. Both Tc-99m complexes showed moderate uptakes in rat brain (0.17% and 0.1% dose/organ at 30 min for the reduced and oxidized forms, respectively). It may be possible to use the same reaction schemes to prepare various derivatives for further studies of these neutral and stable Tc-99m complexes.