The hexamethylpropyleneaminoxime ligand

The lipophilic ^99mTc complex with the tetradentate aminoxime ligand hexamethylpropyleneaminoxime is used for the tomographic depiction of cerebral circulation and to mark blood cells.

This molecule with affinity for the brain is relatively small and lipophilic. The radioactive metal is in the oxidation state +5 and is found in a square-pyramidal coordination environment. Only the meso-isomer of the complex is suitable for brain scintigraphy.