Cages with Tetrahedron-Like Topology Formed from the Combination of Cyclotricatechylene Ligands with Metal Cations
Cages with Tetrahedron-Like Topology Formed from the Combination of Cyclotricatechylene Ligands with Metal Cations
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DOI：
10.1002/anie.201000149
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Robson, Richard
中科院分区：
文献类型：
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作者：
Abrahams, Brendan F.;Fitzgerald, Nicholas J.;Robson, Richard
环三儿茶烯，1a，（ctcH 6）很容易从六醚环三藜芦烯1b得到[1]。因此，令人惊讶的是，很少有人对它的金属配合物进行研究;事实上，据我们所知，以前没有记录过ctc 6配体的配位化合物的例子。由多个金属-配体配位键构建的笼状化合物已经被报道，其中配体，例如下面描述的实施例中的ctc 6配体，充当具有三重对称性的结构单元;所讨论的配体在结构上类似于1b：三个甲氧基被含氮官能团取代，并且配体在金属结合吡啶基供体中封端。[2]最近，我们表明，ctc衍生的阴离子似乎有一个显着的亲和力Cs+和Rb+离子，产生“蛤状”的结构，其中阳离子被困在两个氢键ctc衍生的单位，作为壳的蛤。[3]碱金属阳离子周围的直接环境完全由ctc的内部碳π表面提供，尽管这些化合物是在含有相当大比例的水的混合物中产生的。本文所述的化合物通常通过将碱加入到ctcH 6在二氧六环或丙酮中的混合物和过渡金属盐在水中的混合物（在某些情况下与水溶性共阳离子源如Cs+、Rb+或Ca 2+一起）中获得。当VO ~（2+）和Ca ~（2+）混合使用时，形成晶体，其X射线衍射分析显示出良好定义的[（VO）_6（ctc）_4] 12 π团簇
Cyclotricatechylene, 1a,(ctcH6) is readily obtained [1] from the hexaether cyclotriveratrylene 1b. As such, it is surprising that such little investigation of its metal complexes has been undertaken; indeed, to the best of our knowledge, there are no previously recorded examples of coordination compounds of the ctc6À ligand. Cage compounds, constructed from multiple metal–ligand coordinate bonds, have been reported in which the ligands, such as the ctc6À ligand in the examples described below, act as building blocks with threefold symmetry; the ligands in question are structurally similar to 1b: three methoxy groups were replaced by nitrogen-containing functional groups and the ligands terminated in metalbinding pyridyl donors.[2] Recently, we indicated that ctcderived anions appear to have a marked affinity for Cs+ and Rb+ ions, generating “clamlike” structures in which the cation is trapped between two hydrogen-bonded ctc-derived units that act as the shells of the clam.[3] The immediate environment around the alkali metal cation is provided entirely by the internal carbon π surface of the ctc, and this despite the fact the compounds are generated in mixtures that contain a substantial proportion of water. The preliminary results presented herein indicate the vast potential of the easily generated ctcH6 for providing a wide range of interesting metal derivatives.The compounds described herein were usually obtained by adding base to a mixture of ctcH6 in either dioxane or acetone and the transition-metal salt in water (together in some cases with a water-soluble source of co-cations, such as Cs+, Rb+, or Ca2+). When a combination of VO2+ and Ca2+ was used, crystals were formed, the X-ray diffraction analysis of which revealed well defined [(VO) 6 (ctc) 4] 12À clusters