A Novel Strategy for the Construction of Covalent Organic Frameworks from Nonporous Covalent Organic Polymers

Abstract

The field of covalent organic frameworks (COFs) has been developed significantly in the past decade on account of their important characteristics and vast application potential. On the other hand, the discovery of novel synthetic methodology is still ac hallenging task to further promote the preparation of COFs.H erein, an interesting protocol for the conversion of amorphous nonporous covalent organic polymers (COPs) to COFs was established, affording four COFs with high crystallinity and porosity.S pecifically,i mine-linked amorphous COP-1 was successfully converted to COF-1-4 by replacing one type of linker with other organic building blocks. The realization of this conversion provides afacile method for constructing COFs from COPs.

Integrating Suitable Linkage of Covalent Organic Frameworks into Covalently Bridged Inorganic/Organic Hybrids toward Efficient Photocatalysis

“…Covalent organic frameworks (COFs), comprised of purely organic building blocks linked via robustly covalent bonds, allow atomically precise integration of organic units into extended two- (2D) or three-dimensional (3D) structures with periodic skeletons and ordered nanopores. − COFs provide tunable platforms in skeletons for the mechanistic studies of correlated organic π-systems with exceptionally electronic properties . They have attracted wide attention in semiconductors, , sensors, catalysis, − and energy conversion …”

“…1−6 COFs provide tunable platforms in skeletons for the mechanistic studies of correlated organic π-systems with exceptionally electronic properties. 7 They have attracted wide attention in semiconductors, 8,9 sensors, 10 catalysis, 11−16 and energy conversion. 17 Linkage chemistry is an important aspect to COFs in respect to their practicability in optoelectronics or electrochemical applications.…”

Design, Synthesis and Characterization of Nickel‐Functionalized Covalent Organic Framework NiCl@RIO‐12 for Heterogeneous Suzuki–Miyaura Catalysis

“…Covalento rganic frameworks (COFs) [1] represent af ascinating new type of crystalline porous organic materials, whicha re ingeniously constructed with organic building blocks via strong covalentb onds throught he principleso fr eticular chemistry. [2][3][4][5][6][7][8][9][10][11] In comparison with metal-organic frameworks (MOFs) [12,13] or their inorganic counterparts, zeolites, [14,15] COFs stand out due to their low density, [4,16,17] large surface area, [8,16] good thermals tability, [16] tuneablep ore size, [4,17] structure and functionality designability, [8,18] as well as their versatile covalent bondingo fo rganic synthetic blocks, [19][20][21][22][23] consisting of light elements only. [1,10,17,24] These characteristicsh ave offered the COF materials superior potential in various fields, such as gas storage, [17,25,26] adsorption, [4,27,28] optoelectronics, [29] energy storage [30] and conversion, [31] proton conduction, [32] drug del...…”

Transformation of One-Dimensional Linear Polymers into Two-Dimensional Covalent Organic Frameworks Through Sequential Reversible and Irreversible Chemistries

“…Yaghi and co-workers constructed oxazole- and thiazole-linked frameworks through the addition of appropriately substituted linkers into the imine-COFs after synthesis . In 2018, Zhao and co-workers synthesized crystalline imine-COFs starting from amorphous imine-linked COPs by the addition of different aldehyde monomers . They subsequently reported a linker-substitution strategy to achieve the transformation of imine-COPs to imide-COFs as well as the conversion of imide-COPs to imine-COFs .…”

“…1,2,4 Most COFs are synthesized using dynamic, reversible chemistries, which enable network restructuring and crystallization. 5,6 For example, the dynamic Schiff-base reaction has been widely employed to construct imine COFs 2 and mechanistic studies demonstrated that these COFs are formed through an error-correcting process where the initially formed amorphous polymer networks form crystalline and porous materials through the re-organization of the dynamic imine bonds. 7 The dynamic nature of imine linkages also enables the postsynthetic linker substitution of covalent organic polymers (COPs) or COFs to yield novel crystalline COFs.…”