Recent Progresses in Experimental and Theoretical Studies of Actinide Clusters

Actinide-containing cluster compounds are highly important in radio- and nuclear chemistry. Until three decades ago, little attention had been paid to these heavy-element clusters because of difficulties in their syntheses and characterization as well as handling of these radioactive and chemotoxic elements. In this overview article we have selectively summarized the recent progresses in experimental and theoretical studies on actinide clusters, including actinide (An = Th, Pa, U, Np and Pu) oxide clusters as well as uranyl (UO22+) peroxide clusters and so on. It shows that An(IV) (An = Th, U, Np and Pu) is able to form highly symmetric A(n)(6)(IV)O(8) core clusters and further merge into larger clusters up to An(38)O(56) clusters (An = U, Np and Pu) with the same topology. Meanwhile, An with higher oxidation states such as U(VI) in uranyl is capable to form fullerene-like peroxide cage clusters of U-20, U-60 with the same topology as C-20 and C-60. Relativistic quantum chemistry investigations on the geometric structures, electronic structures and chemical bonding patterns have also been briefly summarized herein to provide an understanding on the structural chemistry of these peculiar clusters. The advances in electronic structure studies of actinide clusters help to develop robust theoretical and computational techniques for the future development of actinide cluster chemistry. Further experimental and computational studies of actinide clusters are needed and helpful to accelerate the development of radio- and nuclear chemistry.