Quantification of electronic structure and nephelauxetic effects in air-sensitive non-aqueous U complexes

U M4,5-edge RIXS measurements are proposed to study the electronic structure and bonding of air-sensitive non-aqueous model complexes that have been synthesised to broaden knowledge of 5f orbital contributions to actinide frontier molecular orbitals. The selected series of molecular U complexes will be used to trace out the sensitivities of RIXS to coordination geometry and metal-ligand covalency. Particular attention is directed towards lower oxidation states U(IV) and U(III). The model complexes selected show evidence from density functional theory of covalent bonding involving the 5f orbitals. The results will be relevant to nuclear waste clean-up and recycling processes.