Our group has focused on the organometallic chemistry of rare-earth metals and actinides for a decade. By installing ferrocene diamide ligands at electropositive metal centers, we have been able to disclose unprecedented reactivity toward aromatic N-heterocycles, arenes, and other small molecules such as P 4 . Systematic studies employing X-ray crystallography, spectroscopy, cyclic voltammetry, and DFT 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 to study intriguing fundamental problems but also led to fruitful chemistry including small molecule activation and controlled co-polymerization reactions.3