Inverted sandwich arene complexes of uranium

The chemistry of arene complexes of uranium has for over half a century been an important facet of organoactinide chemistry. Within this extensive and burgeoning field, in the past two decades inverted sandwich complexes have emerged incorporating cyclobutadienyl, arene, cycloheptatrienyl, and cyclooctatetraenyl ligands. Herein, the field is reviewed with an emphasis on well-defined molecular species that have been unambiguously characterised by X-ray crystallography.