Multifaceted half-sandwich arene–ruthenium complexes: interactions with biomolecules, photoactivation, and multinuclearity approach
Biological properties of the arene–ruthenium complexes have attracted substantial current interest. Their activity is appreciably defined and controlled by the arene moieties, organic ligands and the metal center. In this review, we discuss the interaction of arene–ruthenium complexes with significant biomolecular targets (DNA and enzymes). Principally, active complexes may interact with the biomolecular targets DNA or nucleobases either by direct coordination facilitated by aquation of the complex or by intercalation/stacking of the pendant planar part of the complex, usually from the planar ancillary ligands or arenes with extended rings, between the DNA base pairs. On the other hand, kinetically inert metal complexes can also provide a potential tool (as enzyme inhibitors) for the targeting of important biomolecules (other than DNA), such as protein kinases. At the same time, coordination with a metal facilitates the outreach of the organic molecules in the intracellular region. This review also highlights the photodriven activation of arene–ruthenium complexes, important metal–drug interactions and the potential of multinuclear scaffolds as important drug candidates (e.g., metallodendrimers) and drug carriers (e.g. metallacages) for targeted delivery and activity.