A modular platform for the precise assembly of molecular frameworks composed of ion pairs
A modular platform for the precise assembly of molecular frameworks composed of ion pairs
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DOI：
10.1016/j.chempr.2023.01.011
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发表时间：
2023-02
期刊：
影响因子：
23.5
通讯作者：
Luke P Skala;C. Stern;Laura Bancroft;Casandra M. Moisanu;Chloe E Pelkowski;Xavier Aguilar-Enriquez;Jeremy L. Swartz;M. Wasielewski;William R. Dichtel
中科院分区：
文献类型：
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作者：
Luke P Skala;C. Stern;Laura Bancroft;Casandra M. Moisanu;Chloe E Pelkowski;Xavier Aguilar-Enriquez;Jeremy L. Swartz;M. Wasielewski;William R. Dichtel
静电相互作用通常是非定向的，这使得它们用于设计有序分子框架的用途变得复杂。然而，离子对受体，如杯[4]吡咯，除了在溶液和固态中具有特定结合几何形状的阴离子之外，还定向阳离子。利用这种高度的空间取向来组装扩展的离子对阵列。杯[4]吡咯组件是高度可调的和模块化的，如通过单晶X射线衍射表征的2D层状晶体或1D梯形聚合物的七个实例所示。此外，这些组件保持其结晶度和孔隙率后，去除溶剂。获得了基于四硫富瓦烯结构单元的二维框架的单晶，并且这些自旋活性材料的三重态的特征在于具有瞬态电子顺磁共振（TREPR）光谱。这些结果表明，杯[4]吡咯组装体是一种多功能的新型超分子框架，具有将功能有机亚基组织成设计的固态结构的有趣的可能性。
Electrostatic interactions are typically non-directional, which complicates their use for designing ordered molecular frameworks. However, ion-pair receptors, such as calix[4]pyrroles, orient cations in addition to anions with a specific binding geometry in solution and the solid state. This high degree of spatial orientation was leveraged to assemble extended arrays of ion pairs. Calix[4]pyrrole assemblies are highly tunable and modular, as demonstrated in seven examples of 2D layered crystals or 1D ladder polymers characterized by single-crystal X-ray diffraction. Moreover, these assemblies maintain their crystallinity and porosity following the removal of solvent. Single crystals of a 2D framework based on tetrathiafulvalene building blocks were obtained, and the triplet state of these spin-active materials was characterized with transient electron paramagnetic resonance (TREPR) spectroscopy. These results demonstrate that calix[4]pyrrole assemblies are a versatile new class of supramolecular frameworks that hold intriguing possibilities for organizing functional organic subunits into designed solid-state structures.