Synthesis, characterization and biodistribution of new 99mTc Oxo and nitrido complexes of unsaturated tetradentate (N2S2)ligands.

Three unsaturated Schiff base tetradentate (N2S2 or N2SO) ligands were synthesized and characterized. Oxo and nitrido 99m-technetium complexes were obtained with these ligands. The nitrido complexes were formed using a new easy method available as a kit. When injected into rats and mice, these lipophilic complexes were able to cross the blood-brain barrier but brain perfusion imaging could not be performed due to the insufficient uptake and retention time.