Synergistic Effects of Metals in a Promising RuII−PtIIAssembly for a Combined Anticancer Approach: Theoretical Exploration of the Photophysical Properties

RuII−PtIIcomplexes are a class of bioactive molecules of interest as anticancer agents that combine a light-absorbing chromophore with a cisplatin-like unit. The results of a DFT and TDDFT investigation of a RuIIcomplex and its conjugate with a cis-PtCl2moiety reveal that a synergistic effect of the metals makes the assembly a promising multitarget anticancer drug. Inspection of type I and type II photoreactions and spin–orbit coupling computations reveals that the cis-PtCl2moiety improves the photophysical properties of the RuIIchromophore, ensuring efficient singlet oxygen generation and making the assembly suitable for photodynamic therapy. At the same time, the RuIIchromophore promotes a new alternative activation mechanism of the PtIIligand via a triplet metal-to-ligand charge transfer (3MLCT) state, before reaching the biological target. The importance of the supramolecular architecture is accurately derived, opening interesting new perspectives on the use of bimetallic RuII−PtIIassemblies in a combined anticancer approach.