Supramolecular Engineering of Intrinsic and Extrinsic Porosity in Covalent Organic Cages
Supramolecular Engineering of Intrinsic and Extrinsic Porosity in Covalent Organic Cages
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DOI：
10.1021/ja2056374
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发表时间：
2011-10-19
影响因子：
15
通讯作者：
Cooper, Andrew I.
中科院分区：
文献类型：
--
作者：
Bojdys, Michael J.;Briggs, Michael E.;Cooper, Andrew I.
在分离、储存和催化等应用中，控制合成多孔材料的孔大小、形状和连通性非常重要。结晶有机笼状分子可以表现出永久性的孔洞，但几乎没有合成方法来控制晶体堆积，从而控制孔的连通性。通常，孔隙度是“内在的”(分子内)或“外在的”(分子间)，但不是两者兼而有之。我们报道了一种组装多孔有机笼子的超分子方法，这种方法涉及大量的定向基团，这些基团阻碍了晶体填充。这以一种综合设计的方式在本质上多孔性的保持架单元之间产生了额外的“外部”孔隙度。其中一个分子晶体的表观Brunauer-Emmett-Teller表面积为854m(2)g(-1)，高于相同尺寸的非功能化笼子的表面积。此外，孔之间的连通性，因此客体吸收，可以通过在笼形模块中引入卤素键合基序来调节。这为分子有机晶体孔隙率的超分子工程提供了一种更广泛的方法。
Control over pore size, shape, and connectivity in synthetic porous materials is important in applications such as separation, storage, and catalysis. Crystalline organic cage molecules can exhibit permanent porosity, but there are few synthetic methods to control the crystal packing and hence the pore connectivity. Typically, porosity is either 'intrinsic' (within the molecules) or 'extrinsic' (between the molecules) but not both. We report a supramolecular approach to the assembly of porous organic cages which involves bulky directing groups that frustrate the crystal packing. This generates, in a synthetically designed fashion, additional 'extrinsic' porosity between the intrinsically porous cage units. One of the molecular crystals exhibits an apparent Brunauer-Emmett-Teller surface area of 854 m(2) g(-1), which is higher than that of unfunctionalized cages of the same dimensions. Moreover, connectivity between pores, and hence guest uptakes, can be modulated by the introduction of halogen bonding motifs in the cage modules. This suggests a broader approach to the supramolecular engineering of porosity in molecular organic crystals.