Discrete stack of an odd number of polarized aromatic compounds revealing the importance of net vs. local dipoles
Discrete stack of an odd number of polarized aromatic compounds revealing the importance of net vs. local dipoles
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DOI：
10.1073/pnas.0810319106
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发表时间：
2009-06
期刊：
影响因子：
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通讯作者：
Y. Yamauchi;M. Yoshizawa;M. Akita;M. Fujita
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文献类型：
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作者：
Y. Yamauchi;M. Yoshizawa;M. Akita;M. Fujita
三个极化的芳香族客体分子（芘-4,5-二酮，1）在水中的有机柱配位笼的盒形空腔中形成三层堆叠。空腔尺寸严格限制了堆叠的平面客体的数量，但不限制客体的方向，因此能够研究偏振客体的离散堆叠及其首选构象。晶体学研究表明，空腔中的客体分子相对于彼此旋转 120°，抵消了净偶极矩而不是局部偶极矩。离散的三重堆叠 1 的独特构象与无限堆叠的 1 的标准头尾构象形成鲜明对比。
Three polarized aromatic guest molecules (pyrene-4,5-dione, 1) form a triple-layered stack in the box-shaped cavity of an organic pillared coordination cage in water. The cavity size strictly limits the number of stacked planar guests but does not restrict guest orientation, and thus enables the study of discrete stacks of polarized guests and their preferred conformations. Crystallographic study shows that the guest molecules in the cavity are rotated 120° with respect to each other, canceling the net dipole moment rather than the local dipole moment. The unique conformation of a discrete, triple stack of 1 sharply contrasts to the standard head-to-tail conformation in infinite stacks of 1.