Nakamura Takashi, Yano Syuhei, Liu Yi-Fu, Nabeshima Tatsuya
Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
Inorg Chem. 2024 Jul 15;63(28):12697-12702. doi: 10.1021/acs.inorgchem.4c01542. Epub 2024 Jul 1.
2,2'-Bipyridyl (bpy) is widely used as a chelating unit for metal complexation but is not usually considered as a hydrogen-bonding unit. This is because the metal-free bpy units are usually in a transoid conformation, and the two nitrogen lone pairs are pointed to the opposite sides. We now report a metallomacrocycle whose three metal-free bpy units are in a cisoid conformation and are fixed in the cavity. The complexation of nickel(II) only at the salen units of the triangular bpytrisalen ligand produced this rigid and planar macrocycle. Its cavity is surrounded by hydrogen-bond acceptors (N of bpy and O of salen), and it was found that unique pentagonal prism clusters of water molecules templated by the cavity were formed in the crystal. This study has not only increased the variation of the synthetic methodologies of multinuclear complexes but has also provided the structural platform on which multiple bpy units exert hydrogen-bonding functions.
2,2'-联吡啶（bpy）作为金属络合的螯合单元被广泛使用，但通常不被视为氢键单元。这是因为无金属的bpy单元通常处于反式构象，且两个氮孤对指向相反的方向。我们现在报道一种金属大环化合物，其三个无金属的bpy单元处于顺式构象并固定在腔内。仅在三角形bpytrisalen配体的salen单元处络合镍（II）产生了这种刚性且平面的大环。其腔被氢键受体（bpy的N和salen的O）包围，并且发现在晶体中形成了由该腔模板化的独特的五角棱柱水分子簇。这项研究不仅增加了多核配合物合成方法的多样性，还提供了一个结构平台，在该平台上多个bpy单元发挥氢键功能。
