Author, as appears in the article.: Zhang X, Wang Y, Morales-Martínez R, Zhong J, de Graaf C, Rodríguez-Fortea A, Poblet JM, Echegoyen L, Feng L, Chen N

Department: Química Física i Inorgànica

URV's Author/s: De Graaf, Cornelis / Poblet Rius, Josep Maria / Rodríguez Fortea, Antonio

Keywords: Fullerenes Electric arcs

Abstract: The nature of actinide-actinide bonds has attracted considerable attention for a long time, especially since recent theoretical studies suggest that triple and up to quintuple bonds should be possible, but little is known experimentally. Actinide-actinide bonds inside fullerene cages have also been proposed, but their existence has been debated intensively by theoreticians. Despite all the theoretical arguments, critical experimental data for a dimetallic actinide endohedral fullerene have never been obtained. Herein, we report the synthesis and isolation of a dimetallic actinide endohedral metallofullerene (EMF), U2@C80. This compound was fully characterized by mass spectrometry, single crystal X-ray crystallography, UV-vis-NIR spectroscopy, Raman spectroscopy, cyclic voltammetry, and X-ray absorption spectroscopy (XAS). The single crystal X-ray crystallographic analysis unambiguously assigned the molecular structure to U2@Ih(7)-C80. In particular, the crystallographic data revealed that the U-U distance is within the range of 3.46-3.79 Å, which is shorter than the 3.9 Å previously predicted for an elongated weak U-U bond inside the C80 cage. The XAS results reveal that the formal charge of the U atoms trapped inside the fullerene cage is +3, which agrees with the computational and crystallographic studies that assign a hexaanionic carbon cage, (Ih-C80)6-. Theoretical studies confirm the presence of a U-U bonding interaction and suggest that the weak U-U bond in U2@Ih(7)-C80 is strengthened upon reduction and weakened upon oxidation. The comprehensive characterization of U2@Ih(7)-C80 and the overall agreement between the experimental data and theoretical investigations provide experimental proof and deeper understanding for actinide metal-metal bonding interactions inside a fullerene cage.

Thematic Areas: Química Materiais Interdisciplinar General chemistry Farmacia Engenharias iv Engenharias iii Engenharias ii Colloid and surface chemistry Ciências biológicas ii Ciências biológicas i Ciências agrárias i Ciência de alimentos Chemistry, multidisciplinary Chemistry (miscellaneous) Chemistry (all) Chemistry Catalysis Biochemistry Astronomia / física

ISSN: 00027863

Author's mail: coen.degraaf@urv.cat antonio.rodriguezf@urv.cat josepmaria.poblet@urv.cat

Author identifier: 0000-0001-8114-6658 0000-0001-5884-5629 0000-0002-4533-0623

Record's date: 2023-02-22

Papper version: info:eu-repo/semantics/acceptedVersion

Link to the original source: https://pubs.acs.org/doi/abs/10.1021/jacs.7b10865

Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Journal Of The American Chemical Society. 140 (11): 3907-3915

APA: Zhang X, Wang Y, Morales-Martínez R, Zhong J, de Graaf C, Rodríguez-Fortea A, Poblet JM, Echegoyen L, Feng L, Chen N (2018). U-2@I-h(7)-C-80: Crystallographic Characterization of a Long-Sought Dimetallic Actinide Endohedral Fullerene. Journal Of The American Chemical Society, 140(11), 3907-3915. DOI: 10.1021/jacs.7b10865

Article's DOI: 10.1021/jacs.7b10865

Entity: Universitat Rovira i Virgili

Journal publication year: 2018

Publication Type: Journal Publications