Tagai Koki, Tanaka Yuya, Yamada Michio, Yoshizawa Michito
Laboratory for Chemistry and Life Science, Institute of Integrated Research, Institute of Science Tokyo, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
Department of Chemistry, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei, Tokyo, 184-8501, Japan.
Angew Chem Int Ed Engl. 2025 Aug 18;64(34):e202510929. doi: 10.1002/anie.202510929. Epub 2025 Jun 25.
Post-functionalization is an advanced, key synthetic method in supramolecular systems, whereas the previous method relies heavily on the substitution on the organic frameworks. Here we report a polyaromatic metallotube capable of dually multi-functionalizing the metal sites in an efficient post-assembly fashion. The Pt(II)-linked tube with tetrachloro groups is prepared from two PtCl hinges and two bent bispyridine ligands in high yield. The new metallotube efficiently converts to tetra-substituted tubes by the first multiple functionalization, through the replacement of the chloro groups with various alkynyl groups. The tubular structures before/after the functionalization are unequivocally confirmed by X-ray crystallographic analysis. A resultant tetraammonium-attached Pt(II)-tube exhibits high water solubility and uptake abilities toward spherical and rod-like compounds. The metallotube strongly binds one molecule of fullerene C in the polyaromatic cavity yet releases it through the second multi-functionalization by tetrabromination of the metal hinges in a quantitative and reversible manner. Even after Bingel reaction within the tube, sterically demanding bis-substituted fullerenes (>∼80% selectivity) are readily released by the second functionalization. The present method, i.e., the use of simple PtCl hinges, will be applicable to wide-ranging metallo-supramolecules to enhance their structural and functional versatilities via post-multi-functionalizations.
后功能化是超分子体系中一种先进的关键合成方法，而之前的方法严重依赖于有机骨架上的取代反应。在此，我们报道了一种能够以高效的组装后方式对金属位点进行双重多功能化的多芳基金属管。具有四氯基团的Pt(II)连接管由两个PtCl铰链和两个弯曲的联吡啶配体高产率制备而成。通过用各种炔基取代氯原子，新的金属管通过首次多重功能化有效地转化为四取代管。功能化前后的管状结构通过X射线晶体学分析得到明确证实。所得的连接四铵的Pt(II)管表现出高水溶性以及对球形和棒状化合物的摄取能力。该金属管在多芳腔中强烈结合一分子富勒烯C，但通过金属铰链的四溴化进行第二次多功能化以定量且可逆的方式将其释放。即使在管内进行宾格尔反应后，空间位阻较大的双取代富勒烯（>∼80%选择性）也能通过第二次功能化轻易释放。本方法，即使用简单的PtCl铰链，将适用于广泛的金属超分子，通过后多功能化增强其结构和功能的多样性。
