Redox activity as a tool for bond activations and functionalizations

"Redox active ligand" assisted/controlled bond transformation is the contemporary approach as an alternative to the classical metal-based transformations. The introduction of ligands that can store or release electrons in a metal complex substitutes the thermodynamically expensive reaction pathways with low lying activation barriers that are easily overcome during the course of a reaction. This chapter aims at providing the reader with a comprehensive picture of what redox active ligands are, electronic structures and spectroscopic properties of some well recognized ligand moieties in the ruthenium coordination sphere and their use as "actor" ligands in an array of reactions. An assorted collection of different ligand frameworks exhibiting different kinds of reactivities, showcases the rational design of ligands which could bring about interesting bond transformations with ligand-centered reactivity.