Synthesis, Characterisation and Cytotoxicity of Rhenium Complexes with Bis(2-pyridylmethyl)amine and Two of Its Derivatives

The synthesis, characterisation, crystal structures and cytotoxicity against HeLa cells of three rhenium complexes fac-[Re(CO)3(PMA)]+ (PMA = bis(2-pyridylmethyl)amine), fac-[Re(CO)3(PMAEth)]+ (PMAEth = bis(2-pyridylmethyl)-2-aminoethanol), and fac-[Re(CO)3(PMAProp)]+ (PMAProp = bis(2-pyridylmethyl)-2-aminopropanol) are reported. The tripodal ligands showed slightly higher cytotoxicity than the coordinated complexes with IC50 values ranging from 10 mu M to 38 mu M. These values, together with the fact that the ligand backbones can be easily modified to introduce higher toxicity, supports the possible use of Rhenium(I) as a theranostic radiopharmaceutical.