Multiple-decker sandwich complexes of f-elements

Abstract

Extended sandwich structures (triple-deckers, tetra-deckers etc.) containing d-transition metals are well established for more than 30 years. In contrast, similar complexes containing lanthanide or actinide elements are still rare. In recent years, however, significant progress has been made in this area. This has mainly been achieved with the use of sterically demanding π-ligands such as pentamethylcyclopentadienyl (=Cp*) or silyl-substituted cyclooctatetraenyl dianions like [C8H5(SiMe3)3-1,3,6]2− (=COT‴). Suitable combinations of such ligands in the coordination sphere of f-elements allowed the synthesis and structural characterization of bent and linear triple-decker sandwich complexes as well as the first tetra-deckers and novel cluster-centered multidecker sandwich complexes. This NJC Perspective article gives an overview on recent achievements in this field and looks forward to future developments.