Manipulating the through-space spin-spin interaction of organic radicals in the confined cavity of a self-assembled cage
Manipulating the through-space spin-spin interaction of organic radicals in the confined cavity of a self-assembled cage
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DOI：
10.1002/asia.200600293
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发表时间：
2007-01-01
影响因子：
4.1
通讯作者：
Fujita, Makoto
中科院分区：
文献类型：
--
作者：
Nakabayashi, Koji;Kawano, Masaki;Fujita, Makoto
我们展示了一种利用自组装M6 L4配位笼的封闭腔来操纵贯穿空间自旋-自旋相互作用的新方法。配位笼很容易将稳定的有机自由基包裹在溶液中，这使得自由基的自旋中心彼此更接近。与在没有笼的情况下溶液中的自由基处于双重态的事实形成鲜明对比的是，在存在笼的情况下，通过在溶液中以及在固态中的笼封装效应诱导通过空间自旋-自旋相互作用，从而导致络合物的三重态。这些结果得到了ESR波谱和X射线晶体学的证实。通过笼中的包封产生的三重态物质的量随着自由基对笼的亲和力的增加而增加。我们估计几种类型的客人和笼在溶液中的循环伏安法之间的亲和力。我们还证明了自组装配位笼内有机自由基的空间相互作用可以通过外部刺激如热或pH来控制。
We show a new approach to manipulating the through-space spin-spin interaction by utilizing the confined cavity of a self-assembled M6L4 coordination cage. The coordination cage readily encapsulates stable organic radicals in solution, which brings the spin centers of the radicals closer to each other. In sharp contrast to the fact that the radical in solution in the absence of the cage is in a doublet state, in the presence of the cage through-space spin-spin interaction is induced through cage-encapsulation effects in solution as well as in the solid state, resulting in the triplet state of the complex. These results were confirmed by ESR spectroscopy and X-ray crystallography. The quantity of triplet species generated by encapsulation in the cage increases with increasing affinity of the radicals to the cage. We estimated the affinity between several types of guests and the cage in solution by cyclic voltammetry. We also demonstrate that the through-space interaction of organic radicals within the self-assembled coordination cage can be controlled by external stimuli such as heat or pH.