(Invited) Actinide Cluster Fullerenes: Clusters and Actinide Bondings inside the Confined Space of Carbon Cage

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2021-01; no. 13; p. 641
• Main Authors: Chen, Ning, Echegoyen, Luis, Zhuang, Jiaxin, Yao, Yangrong, Li, Xiaomeng, Yang, Wei
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society, Inc 30.05.2021
• ISSN: 2151-2043; 2151-2035
• DOI: 10.1149/MA2021-0113641mtgabs

The hollow internal cavity of fullerene buckyballs has been known to be able to encapsulate novel metallic units, especially those otherwise very reactive or virtually impossible to prepare clusters. In this talk, we will present our recent studies of novel cluster endohedral fullerenes, focusing on their unique encapsulated clusters and bonding motifs. The synthesis and characterization of U 2 C@C 80 gives an unprecedented look into a long sought after but heretofore unknown U=C bond which lacks heteroatom support, allowing for detailed structural and electronic insights. 1 Novel actinide cluster fullerenes, U 2 C 2 @ I h (7)-C 80 and U 2 C 2 @ D 3 h (5)-C 78 , were synthesized and fully characterized by mass spectrometry, single crystal X-ray crystallography, UV-vis-NIR , Raman spectroscopy, IR spectroscopy, as well as density functional and multireference wavefunction calculations. The encapsulated U 2 C 2 is the first example of a uranium carbide cluster featuring two U centers bridged by a C≡C unit. The U-C bond distances in these U 2 C 2 clusters are in the range between 2.130-2.421 Å. While the U 2 C 2 cluster in U 2 C 2 @C 80 adopts a butterfly-shaped geometry with a U-C 2 -U dihedral angle of 112.7°and a U-U distance of 3.855 Å, the U-U distance in U 2 C 2 @C 78 is 4.164 Å and the resulting U-C 2 -U dihedral angle is increased to 149.1°. The combined experimental and quantum-chemical results suggest that the formal U oxidation state is +IV in the U 2 C 2 cluster.