Solid-State Structure of Tris-Cyclopentadienide Uranium(III) and Plutonium(III).

The organometallic tris-cyclopentadienide actinide(III) (AnCp3 ) complexes were first reported about 50 years ago. However, up until now, only the NpCp3 solid state structure has been studied. Here we report on the solid state structures of UCp3 and PuCp3 which are isostructural to the Np analogue. The structural models are supported by theoretical calculations and compared to their lanthanide analogues. The observed trends in changes of bond lengths might be indicator for an increased covalency in the bonding in the tris-cyclopentadienide actinide(III) complexes (AnCp3 ) compared to their lanthanide homologues.