Th@C2(8)-C84 and Th@Cs(15)-C84: impact of actinide metal ions on the electronic structures of actinide endohedral metallofullerenes

Identifier:  imarina:9331477

Handle: https://hdl.handle.net/20.500.11797/imarina9331477

Authors:  Cao, TT; Meng, QY; Fu, Z; Shen, Y; Yan, YJ; Wang, Q; Zhao, B; Wang, WX; Merimi, K; Rodríguez-Fortea, A; Yao, YR; Chen, N

Abstract:
Two novel thorium-based endohedral metallofullerenes (EMFs), Th@C-2(8)-C-84 and Th@C-s(15)-C-84, have been successfully synthesized and fully characterized by MALDI-TOF mass spectroscopy, single-crystal X-ray diffraction, UV-vis-NIR spectroscopy, cyclic voltammetry, and DFT computations. The molecular structures of Th@C-2(8)-C-84 and Th@C-s(15)-C-84 were unambiguously determined by single-crystal X-ray crystallography, which differ from the previous theoretical prediction that the most stable structure among the Th@C-84 isomers is Th@C-s(10)-C-84. These results, together with the previous reports of the isomers of U@C-84, show that the C-2(8)-C-84 cage can only be stabilized by the encapsulation of actinide metals (U and Th). Detailed structural analysis shows that, in these structures, the encapsulated actinide atom has a unique interaction with the sumanene-type hexagon, which likely contributes to the stabilization of the endohedral molecular structures. Moreover, the two thorium-based EMFs show UV-vis-NIR spectra and redox behaviors that are notably different from those of the previously reported U@C-84 isomers with the same carbon cages, suggesting that, different from lanthanide-based EMFs, endohedral actinide metal atoms have an important impact on the electronic structures of actinide metallofullerenes.