Growth of single-crystal imine-linked covalent organic frameworks using amphiphilic amino-acid derivatives in water

Abstract

Z. (2023). Growth of single-crystal imine-linked covalent organic frameworks using amphiphilic amino-acid derivatives in water. Nature Chemistry.

Impact of the Crystallinity of Covalent Organic Frameworks on Photocatalytic Hydrogen Evolution

“…Using this strategy, both two-and threedimensional COFs have been synthesized as single crystals with high yields on the gram scale. 108 It is worth noting that threedimensional COFs can be isolated as large single crystals, 109,110 but the application of such COFs for photocatalysis is still rare, which may be due to their lower photogenerated carrier mobilities and the break in conjugation due to the central sp 3 carbon atom in the tetrahedral linker. 111 The reaction conditions and linkers for COF crystallization also affect the long-range ordering in COF structures as follows:…”

“…The amphiphilic molecules self-assemble into micelles, which regulate the polymerization and crystallization processes by acting as dynamic barriers to separate monomers in aqueous solution and hydrophobic compartments of the micelles. Using this strategy, both two- and three-dimensional COFs have been synthesized as single crystals with high yields on the gram scale . It is worth noting that three-dimensional COFs can be isolated as large single crystals, , but the application of such COFs for photocatalysis is still rare, which may be due to their lower photogenerated carrier mobilities and the break in conjugation due to the central sp 3 carbon atom in the tetrahedral linker …”

Cyclodextrin Incorporation into Covalent Organic Frameworks Enables Extensive Liquid and Gas Chromatographic Enantioseparations

“…COFs are emerging as an innovative category of crystalline porous materials constructed from light elements (C, H, O, N, B, and Si) through the formation of robust organic covalent bonds in a periodic arrangement. − With permanent porosity and tunable structures, COFs have been explored in a variety of applications, such as gas storage, molecule separation, heterogeneous catalysis, sensing, and energy storage. − By far, several chiral COFs (CCOFs) have been investigated as CSPs for GC, HPLC, and capillary electrochromatography. − In our previous work, two highly stable olefin-linked CCOFs, which are prepared from BINOL-crown ether monomer, have been reported to be utilized as potentially universal CSPs for GC and HPLC, but their practical applications are still hampered by the high synthesis difficulties and economic cost of the monomer and CCOFs . Except for the olefin-linked CCOFs, most of the CCOFs-based CSPs have demonstrated a limited substrate scope and inadequate separate factors.…”

Intermediate Formation of Macrocycles for Efficient Crystallization of 2D Covalent Organic Frameworks with Enhanced Photocatalytic Hydrogen Evolution

“…[22][23][24][25] Recently, several reports have been published on the growth of single crystals of 2D and 3D COFs. [26][27][28][29][30] For example, Zhao and coworkers have highlight the significance of self-assembly and template growth in obtaining highly crystalline COFs during the nucleation and self-healing growth stages. [29] Especially, self-assembly and prearrangement of monomers and oligomers play crucial roles in explaining why the chemical structures of monomers and COF growth conditions (e.g., solvent selection) are critical factors.…”

“…The degree of crystallinity can be also adjusted by specifically tuning the noncovalent interactions between monomers or layers through various methods including modifying the electronic structure of the aromatic rings, forming donor‐acceptor complexes, introducing dipole cancellation or hydrogen bonding between layers, and improving the monomer or layer planarity [22–25] . Recently, several reports have been published on the growth of single crystals of 2D and 3D COFs [26–30] . For example, Zhao and co‐workers have highlight the significance of self‐assembly and template growth in obtaining highly crystalline COFs during the nucleation and self‐healing growth stages [29] .…”