Rare earth and actinide bulky silylamide chemistry

Rare earth (RE) and actinide (An) bis(trimethylsilyl)amide ({N(SiMe 3 ) 2 } − , N′′) chemistry has been investigated for over fifty years, and is very well-established. The hard N-donor atom and bulky trimethylsilyl groups of N′′ provide considerable thermodynamic and kinetic stability, enabling control of RE and An metal coordination spheres for varied applications. By contrast, the RE and An chemistry of other bulky mono(silyl)amides ({N(SiR 3 )(R)} − ) or bis(silyl)amides ({N(SiR 3 ) 2 } − ) is relatively immature. This discrepancy is surprising given the ubiquity of N′′, and that variation of ligand steric and electronic effects is a well-established method to fine-tune RE and An ion accessibility and electronic structure. Here we review RE and An complexes containing silylamide ligands that are of similar or greater steric bulk than N′′, which have surged in popularity recently as such complexes can show promising single-molecule magnet applications.