Zhao Ya, Hu Ziqi, Chuai Panfeng, Jin Huaimin, Yang Shangfeng, Su Jie, Shi Zujin
National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.
Key Laboratory of Precision and Intelligent Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
J Am Chem Soc. 2024 Jun 26;146(25):17003-17008. doi: 10.1021/jacs.4c07045. Epub 2024 Jun 12.
We report here a new type of metal fluoride cluster that can be stabilized inside fullerene via in situ fluorine encapsulation followed by exohedral trifluoromethylation, giving rise to rare-earth metal fluoride clusterfullerenes (FCFs) MF@C(CF) (M = Gd and Y). The molecular structure of GdF@C(CF) was unambiguously determined by single-crystal X-ray analysis to show a μ-fluoride-bridged Gd-F-Gd cluster with short Gd-F bonds of 2.132(7) and 2.179(7) Å. The F NMR spectrum of the diamagnetic YF@C(CF) confirms the existence of the endohedral F atom, which exhibits a triplet with a large F-Y coupling constant of 74 Hz and a high temperature sensitivity of the F chemical shift of 0.057 ppm/K. Theoretical studies reveal the ionic Y-F bonding nature arising from the highest electronegativity of the F element and an electronic configuration of [YF]@[C] with an open-shell carbon cage, which thus necessitates the stabilization of FCFs by exohedral trifluoromethylation.
我们在此报告一种新型金属氟化物簇，其可通过原位氟封装，随后进行外表面三氟甲基化，稳定于富勒烯内部，从而生成稀土金属氟化物簇富勒烯（FCFs）MF@C(CF)（M = Gd和Y）。通过单晶X射线分析明确确定了GdF@C(CF)的分子结构，结果显示其为μ-氟桥联的Gd-F-Gd簇，Gd-F键短，键长为2.132(7) Å和2.179(7) Å。抗磁性YF@C(CF)的F NMR谱证实了内包F原子的存在，该原子呈现出一个三重峰，F-Y耦合常数大，为74 Hz，且F化学位移具有0.057 ppm/K的高温敏感性。理论研究揭示了由于F元素的最高电负性以及具有开壳层碳笼的[YF]@[C]电子构型所产生的离子Y-F键性质，因此需要通过外表面三氟甲基化来稳定FCFs。
