Logelin Madison E, Schreiber Eric, Mercado Brandon Q, Burke Michael J, Davis Caitlin M, Bartholomew Amymarie K
Department of Chemistry, Yale University New Haven Connecticut 06520 USA
Chem Sci. 2024 Aug 20;15(37):15198-204. doi: 10.1039/d4sc03524k.
The synthetic tunability and porosity of two-dimensional (2D) metal-organic frameworks (MOFs) renders them a promising class of materials for ultrathin and nanoscale applications. Conductive 2D MOFs are of particular interest for applications in nanoelectronics, chemo-sensing, and memory storage. However, the lack of covalency along the stacking axis typically leads to poor crystallinity in 2D MOFs, limiting structural analysis and precluding exfoliation. One strategy to improve crystal growth is to increase order along the stacking direction. Here, we demonstrate the synthesis of mechanically exfoliatable macroscopic crystals of a 2D zinc MOF by selective dimensional reduction of a 3D zinc MOF bearing a dianthracene (diAn) ligand along the stacking axis. The diAn ligand, a thermally cleavable analogue of 4,4'-bipyridine, is synthesized by the direct functionalization of dianthraldehyde in a novel "dianthracene-first" approach. This work presents a new strategy for the growth of macroscopic crystals of 2D materials while introducing the functionalization of dianthraldehyde as a means to access new stimuli-responsive ligands.
二维（2D）金属有机框架（MOF）的合成可调性和孔隙率使其成为一类有前途的用于超薄和纳米级应用的材料。导电二维MOF在纳米电子学、化学传感和存储器存储应用中特别受关注。然而，沿堆积轴缺乏共价性通常会导致二维MOF的结晶性较差，限制了结构分析并排除了剥离的可能性。一种改善晶体生长的策略是增加沿堆积方向的有序性。在此，我们通过沿堆积轴对带有二蒽（diAn）配体的三维锌MOF进行选择性尺寸缩减，展示了一种二维锌MOF的可机械剥离宏观晶体的合成方法。二蒽配体是4,4'-联吡啶的热可裂解类似物，通过一种新颖的“二蒽优先”方法由二蒽醛直接功能化合成。这项工作提出了一种二维材料宏观晶体生长的新策略，同时引入二蒽醛功能化作为获取新的刺激响应配体的一种手段。
