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 µM to 38 µM. 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.