Kimika Teorikoa Seminar: Mechanistic Insights into Ligand Photodissociation in Ru(II) Complexes for PACT Applications

Ruthenium(II) complexes have emerged as promising candidates for phototherapeutic applications. They are primarily investigated for Photodynamic Therapy (PDT) and Photoactivated Chemotherapy (PACT). In PDT, light-triggered population of long-lived excited states (e.g. 3 MLCT or 3 LC) enables the efficient generation of reactive oxygen species (ROS), which induce cellular oxidative stress. Conversely, PACT requires 3 MLCT- 3 MC conversion and the subsequent population of 3 MC states, as these have dissociative character and can promote the release of bioactive ligands and/or the formation of reactive Ru-aqua species. Therefore, the predominance of PDT or PACT activity depends on 3 MLCT- 3 MC energy barriers and excited-state lifetimes. Understanding these excited-state pathways helps optimize photodissociation efficiency and Density Functional Theory (DFT) is a reliable method for studying photochemical reactions. The topic of this seminar is the computational investigation of photodissociation mechanisms in Ru(II)-acetonitrile complexes, focusing on how 3 MLCT- 3 MC conversion, ligand release, and subsequent water coordination influence their photochemical efficiency as PACT agents.