Dynamic self-assembly of an M3L6 molecular triangle and an M4L8 tetrahedron from naked PdII ions and bis(3-pyridyl)-substituted arenes
Dynamic self-assembly of an M3L6 molecular triangle and an M4L8 tetrahedron from naked PdII ions and bis(3-pyridyl)-substituted arenes
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DOI：
10.1002/asia.200600029
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发表时间：
2006-07-01
影响因子：
4.1
通讯作者：
Fujita, Makoto
中科院分区：
文献类型：
--
作者：
Chand, Dillip K.;Biradha, Kumar;Fujita, Makoto
以吡啶为配体的非螯合双齿配体1，4-双（3-吡啶基）苯（1）和4，4 '-双（3-吡啶基）联苯（2）与裸钯离子配位，构建了分子笼化合物。在这些实验之前，还检查了配体与顺式-[Pd（en）（NO3）（2）]的络合，因为预期来自顺式保护的Pd-II离子的自组装体是构成来自裸Pd-II离子的组装体的简单基序。化合物1和[Pd（en）（NO3）（2）]的自组装结构与溶剂有关。在水溶液中，获得M2 L2沟槽状化合物。然而，在二甲基亚砜中，M2 L2沟和M3 L3大环的混合物被发现处于平衡状态，其动态性质由该物种的浓度依赖性证实。在较高浓度下，主要观察到M4 L4大环化合物。1与裸Pd-II离子的络合预期产生作为MnLn型框架的组合的新颖结构。由1和Pd（NO3）（2）定量地得到了一个奇特的四面体M4 L 8组装体，而不是可能的最小的M3 L 6双壁三角形。有趣的是，使用Pd（CF 3SO 3）（2）导致后一种结构的唯一形成。因此，阴离子在这些组装体的形成中作为模板是重要的。与1相比，含有额外对亚苯基单元的配体2在用[Pd（en）（NO3）（2）]处理时表现出类似的方式，但与裸Pd-II离子显示出细微的差异。与Pd（NO_3）（2）配合时，2主要形成一个沿着的四面体和一个双壁三角形。与Pd（CF 3SO 3）（2）一起，这个较长的配体形成了一个双壁三角形，四面体的数量可以忽略不计。通过选择对甲苯磺酸盐作为反离子，由2和Pd-II离子获得了完整四面体的单个离散组装体。
The pyridine-appended nonchelating bidentate ligands 1,4-bis(3-pyridyl)benzene (1) and 4,4'-bis(3-pyridyl) biphenyl (2) were complexed with a naked Pd-II ion for the construction of molecular cage compounds. Prior to these experiments, the complexation of the ligands with cis-[Pd(en)(NO3)(2)] was also examined, because self-assemblies from the cis-protected Pd-II ion were expected to be simple motifs that constitute the assemblies from naked Pd-II ion. The structures of the self-assembled compounds resulting from 1 and [Pd(en)(NO3)(2)] depended on the solvent employed. In aqueous solution, an M2L2 trenchlike compound was obtained. In dimethyl sulfoxide, however, a mixture of the M2L2 trench and an M3L3 macrocycle was found in equilibrium, the dynamic nature of which was confirmed by the concentration-dependent nature of the species. At higher concentration, an M4L4 macrocycle was mostly observed. The complexation of 1 with naked Pd-II ions was expected to produce novel structures that are combinations of the MnLn type frameworks. A peculiar tetrahedral M4L8 assembly was obtained quantitatively from 1 and Pd(NO3)(2), rather than the smallest possible M3L6 double-walled triangle. In terestingly, the use of Pd(CF3SO3)(2) resulted in the sole formation of the latter structure. Thus, the anion is important as a template in the formation of these assemblies. Ligand 2, which contains an extra p-phenylene unit compared to 1, behaved in a similar manner when treated with [Pd(en)(NO3)(2)], but showed subtle differences with naked Pd-II ions. With Pd(NO3)(2), 2 gave mostly a tetrahedron along with a double-walled triangle. With Pd(CF3SO3)(2), this longer ligand formed a double-walled triangle with a negligible amount of tetrahedra. A single discrete assembly of a perfect tetrahedron was obtained from 2 and Pd-II ions by choosing p-tosylate as a counterion.