Porphine dimeric assemblies in organic-pillared coordination cages.
Porphine dimeric assemblies in organic-pillared coordination cages.
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DOI：
10.1002/anie.200604790
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发表时间：
2007-03
影响因子：
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通讯作者：
K. Ono;M. Yoshizawa;Tatsuhisa Kato;Kentaroh Watanabe;M. Fujita
中科院分区：
文献类型：
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作者：
K. Ono;M. Yoshizawa;Tatsuhisa Kato;Kentaroh Watanabe;M. Fujita
卟啉二聚体和寡聚体的 π 堆叠结构在仿生和仿生化学以及材料科学等许多领域引起了人们的极大兴趣。[1, 2] 此类组装体的性能受到其空间排列的显着影响。先前已通过 1) 共价间隔基、[3, 4] 2) 氢键、[5] 或 3) 静电相互作用连接两个卟啉分子制备了共面堆叠的卟啉二聚体。 [6]然而，卟啉二聚体的合成和功能化仍然受到限制，因为所有这些方法都需要对卟啉环进行精确且有时复杂的修饰以形成二聚体。我们在这里重点关注的另一种有前途的方法是利用主客体 π 堆积相互作用，其中不需要对卟啉核心进行任何直接修改。在此，我们报告了卟啉二聚体在有机柱笼的盒形腔中的组装。根据空腔尺寸，两个卟啉分子直接堆叠（A；图 1）或用芳香族间隔基分层（B）。它们表现出独特的 UV/Vis 吸收和 ESR 光谱（当卟啉客体含有 CuII 时），具体取决于腔中的堆积方式。我们最近报道了由两个板状配体、三个柱状配体和六个顺式保护的 Pd 配合物自组装有机柱配位笼 1 和 2（图 1）。 [7]盒状主体的空腔很大并且足够适合通过π堆积相互作用容纳两个或三个大平面芳香族化合物分子。因此，我们利用这些宿主来介导卟啉二聚体的形成。据我们所知，目前还没有关于可以在腔内完全封装两个或多个卟啉或卟啉分子的合成宿主的报道。 [8]检查了 1 与卟啉 3a 的络合（图 2a）。当不溶于水的3a（40.0μmol）的紫红色粉末在室温下悬浮在1（10.0μmol）的D2O（1.0mL）无色溶液中12小时时，
The π-stacked structure of porphyrin dimers and oligomers attracts considerable interest in many areas such as biomimetic and bioinspired chemistry and material science.[1, 2] The property of such assemblies is significantly affected by their spatial arrangement. Cofacially stacked porphyrin dimers have been previously prepared by linking the two porphyrin molecules by 1) covalent spacer (s),[3, 4] 2) hydrogen bonding,[5] or 3) electrostatic interactions.[6] However, the synthesis and the functionalization of porphyrin dimers are still limited because all of these methods need precise and sometimes complicated modification on the porphyrin ring to form the dimers. Another promising method, which we focus on here, is to utilize host–guest π-stacking interactions, where any direct modifications on the porphine core are not required. Herein, we report the assembly of porphine dimers in the boxshaped cavity of organic-pillared cages. Depending on the cavity size, two porphine molecules are stacked directly (A; Figure 1) or layered with an aromatic spacer (B). They exhibit unique UV/Vis absorption and ESR spectra (when the porphine guest contains CuII), depending on the manner of stacking in the cavity.We recently reported the self-assembly of organic-pillared coordination cages 1 and 2 from two panel-like ligands, three pillar-like ligands, and six cis-protected Pd complexes (Figure 1).[7] The cavities of the box-shaped hosts are large and well-fitting enough to accommodate two or three molecules of large planar aromatics by π-stacking interactions. Therefore, we employed these hosts to mediate the formation of the porphine dimers. To our knowledge, there are no reports on synthetic hosts that can fully encapsulate two or more porphine or porphyrin molecules in the cavity.[8] The complexation of 1 with porphine 3a was examined (Figure 2 a). When a purple-red powder of water-insoluble 3a (40.0 μmol) was suspended in a colorless solution of 1 (10.0 μmol) in D2O (1.0 mL) for 12 h at room temperature,