Light-active cyclometalated Pt complexes: optical and biological properties

There is a growing need for the development of metallodrugs to reduce the adverse anticancer side effects and also on novel approaches such as photodynamic therapies (PDT). In this context, cyclometalated Pt(II) complexes have proved particularly promising alternatives as anticancer agents [1], with several advantages. Their high stability may allow them to reach the cell unaltered, the aromatic groups in the cyclometalated ligand might favor intercalative binding to DNA through and the presence of ··· stacking, (Pt-C) bond increases the lability of the ligand in trans, a priori favoring the coordination to DNA, as for cisplatin. Moreover, cycloplatinated(II) complexes usually display luminescence properties [2] with long-lived excited states, tunable ligands, high quantum yields and cellular uptake, properties of interest in further application in bioimaging and biosensing [2] and as excellent photosensitizers (PS) for the production of reactive oxygen species (ROS) [3]. On the other hand, despite the increasing importance of octahedral Pt(IV)-based complexes as prodrugs and multi-acting targets in antitumor therapeutics [4], reports on the biological activity of luminescent cyclometalated Pt(IV) derivatives remain sparse. During this talk, we will present some of our results on the synthesis, characterization, optical properties and biological evaluation of cyclometalated C^N platinum(II) and Pt(IV) derivatives.