Study of Metallofullerenes Encapsulating Actinides

Abstract

The oxidation state of actinide elements encapsulated in fullerenes is studied. HPLC elution behavior of actinidefullerenes is classified into two groups; the elution behavior of the first group, encapsulating U, Np, and Am, issimilar to that of the light lanthanide fullerenes, such as La, Ce, Pr, and Nd, while the behavior of the second group, encapsulating Th and Pa, is quite different from that of any lanthanide fullerenes. The chemical species in the mainHPLC elution peak of each group were identified as M @C₈₂ and M @C₈₄ (M=metal atom) from the mass of the U and Th fullerenes, respectively. The oxidation states of the U and Th atoms in the fullerenes were deduced to be 3+ and 4+, respectively, from the UV/vis/NIR absorption and XANES spectroscopy.