Single-Crystalline Imine-Linked Two-Dimensional Covalent Organic Frameworks Separate Benzene and Cyclohexane Efficiently,Journal of the American Chemical Society

当前位置： X-MOL 学术 › J. Am. Chem. Soc. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Single-Crystalline Imine-Linked Two-Dimensional Covalent Organic Frameworks Separate Benzene and Cyclohexane Efficiently
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2022-10-20 , DOI: 10.1021/jacs.2c07166
Anusree Natraj ₁ , Woojung Ji ₁ , Junjie Xin ₂ , Ioannina Castano ₁ , David W Burke ₁ , Austin M Evans ₁ , Michael J Strauss ₁ , Mohamed Ateia ₁ , Leslie S Hamachi ₁ , Nathan C Gianneschi _{1,

3,

4} , Zeid A ALOthman ₅ , Junliang Sun ₂ , Kareem Yusuf ₅ , William R Dichtel ₁

Affiliation

Two-dimensional (2D) covalent organic frameworks (COFs) are composed of structurally precise, permanently porous, layered macromolecular sheets, which are traditionally synthesized as polycrystalline solids with crystalline domain lengths smaller than 100 nm. Here, we polymerize imine-linked 2D COFs as suspensions of faceted single crystals in as little as 5 min at moderate temperature and ambient pressure. Single crystals of two imine-linked 2D COFs were prepared, consisting of a rhombic 2D COF (TAPPy-PDA) and a hexagonal 2D COF (TAPB-DMPDA). The sizes of TAPPy-PDA and TAPB-DMPDA crystals were tuned from 720 nm to 4 μm and 450 nm to 20 μm in width, respectively. High-resolution transmission electron microscopy revealed that the COF crystals consist of layered, 2D polymers comprising single-crystalline domains. Continuous rotation electron diffraction resolved the unit cell and crystal structure of both COFs, which are single-crystalline in the a–b plane but disordered in the stacking c dimension. Single crystals of both COFs were incorporated into gas chromatography separation columns and exhibited unusual selective retention of cyclohexane over benzene, with single-crystalline TAPPy-PDA significantly outperforming single-crystalline TAPB-DMPDA. Polycrystalline TAPPy-PDA exhibited no separation, while polycrystalline TAPB-DMPDA exhibited poor separation and the opposite order of elution, retaining benzene more than cyclohexane, indicating the importance of improved material quality for COFs to exhibit properties that derive from their precise, crystalline structures. This work represents the first example of synthesizing imine-linked 2D COF single crystals at ambient pressure and short reaction times and demonstrates the promise of high-quality COFs for molecular separations.

中文翻译：

单晶亚胺连接的二维共价有机骨架高效分离苯和环己烷

二维 (2D) 共价有机框架 (COF) 由结构精确、永久多孔、分层的大分子片组成，传统上合成为晶畴长度小于 100 nm 的多晶固体。在这里，我们在中等温度和环境压力下，在短短 5 分钟内将亚胺连接的二维 COF 聚合为多面单晶的悬浮液。制备了两个亚胺连接的二维 COF 的单晶，由一个菱形二维 COF ( TAPPy-PDA ) 和一个六边形二维 COF ( TAPB-DMPDA ) 组成。TAPPy-PDA和TAPB-DMPDA 的尺寸晶体的宽度分别从 720 nm 调整到 4 μm 和 450 nm 到 20 μm。高分辨率透射电子显微镜显示，COF 晶体由包含单晶域的层状二维聚合物组成。连续旋转电子衍射解析了两种 COF 的晶胞和晶体结构，它们在a - b平面上是单晶的，但在堆叠c维度上是无序的。将两种 COF 的单晶结合到气相色谱分离柱中，并表现出对环己烷相对于苯的不同寻常的选择性保留，单晶TAPPy-PDA 的性能明显优于单晶TAPB-DMPDA。多晶TAPPy-PDA没有表现出分离，而多晶TAPB-DMPDA表现出较差的分离性和相反的洗脱顺序，比环己烷更多地保留苯，这表明提高材料质量对于 COF 表现出源自其精确晶体结构的特性的重要性。这项工作代表了在环境压力和短反应时间下合成亚胺连接的二维 COF 单晶的第一个例子，并证明了高质量 COF 用于分子分离的前景。

更新日期：2022-10-20

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南