Organoruthenium-bipyridyl complexes – A platform for diverse chemistry and applications

The increasing impact of organometallic complexes of group 8–10 metals academically and industrially over the years demonstrates remarkable progress in harvesting useful reagents, catalysts, and chemotherapeutic agents. In particular, apart from the important catalytic applications, organoruthenium complexes have been widely investigated for exploring advanced photophysical and medicinal properties in treating different types of cancers through photodynamic therapy. Since there are several limitations with the therapeutic applications of many existing platinum-based drugs including severe side effects, toxicity, scarce selectivity and multifaceted drug resistance, there has been a strong demand for the development of alternative solutions. Owing to the high potential of some of the well-designed ruthenium-based complexes, the research has been extensively focused on designing the appropriate ligand systems. Among all the ligand systems employed in the coordination sphere of ruthenium, the bipyridyl ligands supported organoruthenium complexes have been extensively studied. Notably, a subtle change in the steric and electronic properties of bipyridyl ligand facilitates unusual features required for a variety of applications. For example, these bipyridyl-Ru complexes facilitate the designing of efficient dye-sensitized solar cells and a variety of efficient anti-cancer and anti-malarial activities. In addition, these complexes provide a platform for diverse catalytic applications including hydrogenation, water oxidation, reduction of CO2, etc. The increased bioactivity of bipyridyl-based organoruthenium complexes strongly depends on lipophilicity and the release of functionalized bioactive ligands associated directly with the Ru center including the shape of the metal-complex. This article enhances the understanding of the role of different bipyridyl derivatives of organoruthenium complexes that impart the potential to perform a variety of functions.