A charged diatomic triple-bonded U≡N species trapped in C82 fullerene cages
Qingyu Meng1,6, Laura Abella2,6, Yang-Rong Yao3, Dumitru-Claudiu Sergentu 4,Wei Yang1, Xinye Liu1, Jiaxin Zhuang1, Luis Echegoyen5,Jochen Autschbach 2 *& Ning Chen 1*（谌宁）
1 College of Chemistry, Chemical Engineering and Materials Science, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu 215123, P. R. China.
2 Department of Chemistry, University at Buffalo, State University of New York. Natural Sciences Complex, Buffalo, NY 14260-3000, USA.
3 Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China.
4 A.I. Cuza University of Iași,RA-03 Laboratory (RECENTAIR), Iași 700506,Romania.
5 Department ofChemistry,University of Texas at El Paso, 500WUniversity Avenue, El Paso, Texas 79968, USA.
6 These authors contributed equally: Qingyu Meng, Laura Abella.
Nature Communications ( 2022) 13:7192
Actinide diatomic molecules are ideal models to study elusive actinide multiple bonds, but most of these diatomicmolecules have so far only been studied in solid inert gas matrices. Herein, we report a charged U≡N diatomic species captured in fullerene cages and stabilized by the U-fullerene coordination interaction. Two diatomic clusterfullerenes, viz. UN@Cs(6)-C82 and UN@C2(5)- C82, were successfully synthesized and characterized. Crystallographic analysis reveals U-N bond lengths of 1.760(7) and 1.760(20) Å in UN@Cs(6)-C82 and UN@C2(5)-C82. Moreover,U≡N was found to be immobilized and coordinated to the fullerene cages at 100 K but it rotates inside the cage at 273 K. Quantumchemical calculations show a (UN)2+@(C82)2− electronic structure with formal +5 oxidation state (f1) of U and unambiguously demonstrate the presence of a U≡N bond in the clusterfullerenes. This study constitutes an approach to stabilize fundamentally important actinide multiply bonded species