Hierarchical Self-Organization of Perylene Bisimides into Supramolecular Spheres and Periodic Arrays Thereof
Hierarchical Self-Organization of Perylene Bisimides into Supramolecular Spheres and Periodic Arrays Thereof
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DOI：
10.1021/jacs.6b09986
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发表时间：
2016-11-09
影响因子：
15
通讯作者：
Percec, Virgil
中科院分区：
文献类型：
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作者：
Sahoo, Dipankar;Peterca, Mihai;Percec, Virgil
苝二酰亚胺衍生物（pbi）已知只能形成柱状或层状组装体。目前还没有已知的PBI自组装成超分子球体的例子。因此，由pbi产生的球形组件产生的周期和准周期阵列也不为人所知。在这里，一个具有第二代自组装树突的亚胺基功能化的PBI被报道自组装成超分子球体。这些球体以体心立方（BCC）周期阵列自组织，很少在自组装树突中遇到，但在嵌段共聚物中经常遇到。这些超分子球体也组装成柱状六边形阵列，其中超分子柱出乎意料地前所未有地由球体组成。在较低温度下，观察到PBI的对称和不对称四聚体冠组成的两个附加柱状六方相。通过x射线衍射（XRD）、分子模拟、分子模拟和固态核磁共振分析表明，对称四聚体冠在高温下的反转介导了它们向超分子球的转变。PBIs的四聚体冠由于在高温下的快速分子运动，能够在立方相中形成各向同性的球体，这是用XRD无法观察到的，但用固态核磁共振研究证实了这一点。这种PBI层叠自组织成超分子球的机制很可能是普遍的，可以应用于其他相关的平面分子以产生新的功能。
Perylene bisimide derivatives (PBIs) are known to form only columnar or lamellar assemblies. There is no known example of a PBI self-assembling into a supramolecular sphere. Therefore, periodic and quasiperiodic arrays generated from spherical assemblies produced from PBIs are also not known. Here, a PBI functionalized at its imide groups with a second generation self-assembling dendron is reported to self assemble into supramolecular spheres. These spheres self organize in a body-centered cubic (BCC) periodic array, rarely encountered for self-assembling dendrons but often encountered in block copolymers. These supramolecular spheres also assemble into a columnar hexagonal array in which the supramolecular columns are unexpectedly and unprecedentedly made from spheres. At lower temperature, two additional columnar hexagonal phases consisting of symmetric and asymmetric tetrameric crowns of PBI are observed. Structural and retrostructural analysis via X-ray diffraction (XRD), molecular modeling, molecular simulation, and solid state NMR suggests that inversion of the symmetric tetrameric crowns at high temperature mediates their transformation into supramolecular spheres. The tetrameric crowns of PBIs are able to form an isotropic sphere in the cubic phase due to rapid molecular motion at high temperature, unobservable by XRD but demonstrated by solid state NMR studies. This mechanism of hierarchical self organization of PBI into supramolecular spheres is most probably general and can be applied to other related planar molecules to generate new functions.