The same cannot be said for cytotoxicity and haemolysis data. Part of this can be attributed to the fact that the highest concentration measured in the initial CO-ADD screening is 32 µg/mL which, depending on the molecular weight of the compound, can vary dramatically when translated to molar units. Because the molecular weight of metal complexes generally covers an expanded range compared to organic compounds, all subsequent assays were conducted with molar units to generate comparable data. In essence, this finding highlights that the cytotoxicity of these compounds needs to be evaluated rigorously. It should be noted that the therapeutic indices for most (14/21) compounds tested in the extended panel were still over 50 and many (9/21) were >1000, indicating that they could still be explored further at appropriate dosages (Table in SI).