复旦大学金国新开发了一种通过弯曲联吡啶配体诱导818金属结和Borromean环的超大堆积相互作用的选择性构建策略。相关研究成果于2020年12月31日发表在国际顶尖学术期刊《美国化学会志》。

研究人员通过组分间的多重分子间相互作用，高产率地得到了两个含有500多个非氢原子（特别是16个RhIII离子）的金属分子结和一个分子Borromean环。该合成通过非线性双吡啶基配体L1（2,7-二（吡啶-4-基）-9H-芴）作为前体分子，并通过详细的X射线晶体学分析证实了组装体的结构。

随后，用体积较大的配体4,4′-（9,9-二甲基-9H-芴-2,7-二基）联吡啶（L2）取代L1，由于萘/蒽和芴部分之间的π-π堆积相互作用减弱，从而导致高产率得到三个四核金属环结构分子。进而证实了818金属结分子与Borromean环分子结构构建过程中堆积相互作用的重要性。

附：英文原文

Title: Selective Construction of Very Large Stacking-Interaction-Induced Molecular 818 Metalla-knots and Borromean Ring Using Curved Dipyridyl Ligands

Author: Hai-Ning Zhang, Yue-Jian Lin, Guo-Xin Jin

Issue&Volume: December 31, 2020

Abstract: Two molecular metalla-knots containing over 500 non-hydrogen atoms (especially 16 RhIII ions) and one molecular Borromean ring were obtained in high yields facilitated by multiple intermolecular interactions between their components. The syntheses rely on the strategic selection of the nonlinear dipyridyl ligand 2,7-di(pyridin-4-yl)-9H-fluorene (L1) as precursor, and the structures of the assemblies were confirmed by detailed X-ray crystallographic analysis. Subsequently, replacing L1 with the bulkier ligand 4,4′-(9,9-dimethyl-9H-fluorene-2,7-diyl)dipyridine (L2) led to the formation of three tetranuclear metallocycles in high yields on account of the weakened π–π stacking interactions between the naphthacene/anthracene and fluorene moieties, which in turn confirmed the significance of stacking interactions in the construction of the molecular 818 metalla-knots and the molecular Borromean ring.

DOI: 10.1021/jacs.0c11925

Source: https://pubs.acs.org/doi/10.1021/jacs.0c11925