Reactivity and Properties of Metal Complexes Enabled by Flexible and Redox-Active Ligands with a Ferrocene Backbone

. Systematic studies employing X-ray crystallography, spectroscopy, cyclic voltammetry, and density functional theory calculations revealed that the ferrocene backbone could stabilize the electron-deficient metal through a donor-acceptor-type interaction. Most noteworthy is that this interaction can be readily turned on or off by the addition or removal of a Lewis base. In addition to its flexible coordination, the redox-active nature of the ferrocene backbone enabled us to explore redox-switchable transformations. The introduction of ferrocene-based ligands into organolanthanide chemistry not only helped us to study intriguing fundamental problems but also led to fruitful chemistry including small-molecule activation and controlled copolymerization reactions.