Fullerene encapsulation with calix[5]arenes
Fullerene encapsulation with calix[5]arenes
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DOI：
10.1016/j.tet.2005.07.121
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发表时间：
2006-02-27
期刊：
影响因子：
2.1
通讯作者：
Fukazawa, Y
中科院分区：
文献类型：
--
作者：
Haino, T;Yanase, M;Fukazawa, Y
本文介绍了杯[5]芳烃类富勒烯主体的合成及其结合性能。杯[5]芳烃la，2，3a在有机溶剂中结合C-60或C-70。富勒烯络合的溶剂效应被清楚地观察到;在C-60具有高溶解度的溶剂中，缔合常数降低。并研究了配位的双杯[5]芳烃4-6在有机溶剂中与富勒烯的结合性能。它们在甲苯溶液中对C-60和C-70的结合能力都很强。所有的双杯[5]芳烃对C-70都有较高的结合选择性。5a对C-70/C-60的选择性在甲苯中最高，值为10。用H-1和C-13 NMR研究了杯[5]芳烃主体与C-60或C-70的超分子配合物的结构。分子力学计算和X-射线衍射结构表明杯[5]芳烃的内部与C-60分子的外部是互补的。相反，C-70与简单杯[5]芳烃的主-客体复合物由于其不太对称的形状而具有许多构象选择。分子力学计算和我们的化学位移模拟很好地工作，以估计可靠的结构;杯[5]芳烃空腔占据C-70分子，并且C-70分子从杯[5]芳烃的C5轴显著倾斜。在C-70与双杯[5]芳烃的主-客体复合物的情况下，主-客体复合物的分子动力学模拟代表了结合的C-70在空腔内的真实运动。分子动力学模拟和主客体复合物化学位移模拟的结合表明，C-70分子在空腔内快速运动。(c)2005爱思唯尔有限公司保留所有权利。
This paper presents the synthesis of the fullerene hosts based on the calix[5]arenes and their binding properties. Calix[5]arenes la, 2, 3a bind C-60 or C-70 in organic solvents. The solvent effect of the fullerene complexation was clearly observed; the association constant decreases in a solvent with high solubility for C-60. Covalently linked double-calix[5]arenes 4-6 were also investigated on their binding properties for fullerenes in organic solvents. Their binding abilities for both C-60 and C-70 are extremely high in toluene solution. Higher binding selectivity toward C-70 is observed by all the double-calix[5]arenes. The selectivity of 5a toward C-70/C-60 is highest in toluene with a value of 10. The structures of the supramolecular complexes of the calix[5]arene hosts and C-60 or C-70 were investigated by using H-1 and C-13 NMR studies. The molecular mechanics calculation and X-ray structure reveal that the interior of the calix[5]arene is complementary to the exterior Of C-60 molecule. In contrast, the host-guest complexes Of C-70 With the simple calix[5]arenes take many conformational options due to its less symmetric shape. The molecular mechanics calculation and our chemical shift simulation nicely worked to estimate the reliable structures; the calix[5]arene cavity takes up C-70 molecule, and the C-70 molecule tilts significantly from the C5 axis of the calix[5]arene. In the case of the host-guest complex Of C-70 with the double-calix[5]arene, the molecular dynamics simulation of the host-guest complex represented the realistic movement of the bound C-70 inside the cavity. The combination of the molecular dynamics simulation and the chemical shift simulation of the host-guest complex suggested that the C-70 molecule rapidly moves inside the cavity. (c) 2005 Elsevier Ltd. All rights reserved.