Abstract
In the fight against cancer, photodynamic therapy is generating great interest thanks to its ability to selectively kill cancer cells without harming healthy tissues. In this field, ruthenium(II) polypyridyl complexes, and more specifically, complexes using dipyrido[3,2‐a:2’‐3’‐c]phenazine (dppz) as a ligand are of particular interest due to their DNA‐binding and photocleaving properties. However, ruthenium(II) polypyridyl complexes can sometimes suffer from low lipophilicity, which hampers their cellular internalisation through passive diffusion. In this study, 4 new [Ru(dppz‐X 2 ) 3 ] 2+ (where X = H, F, Cl, Br, I) were synthesized and their lipophilicity (Log P ), cytotoxicity and phototoxicity on cancerous and non‐cancerous cell lines assessed. This study shows that the phototoxicity of these complexes counterintuitively decreases when their lipophilicity increases, which could be due solely to the atomic radius of the halogen substituents.