Synthesis, Properties, and Their Potential Application of Covalent Organic Frameworks (COFs)

Abstract

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous polymers, which are ingeniously assembled with organic building blocks through reversible covalent bonds. The well-defined crystalline porous structures, easy functional modification, high surface area, together with structural designability and diversity have offered the COFs superior potential in various applications, such as catalysis, gas adsorption and separation, and optoelectricity. Since the pioneer work of Omar Yaghi in 2005, this field has developed rapidly and attracted much attention from researchers with diverse expertise. In this chapter, we describe the basic design concepts, the recent synthetic advancements, and the frontiers of functional exploration in gas adsorption and storage. Special emphasis is placed on their potential application in heterogeneous catalysis field. Finally, the prospects of COFs and remaining issues in these fields are indicated.

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...…”

Highly Thermostable Dynamic Structures of Polyaramid Two-Dimensional Polymers

“…From the prior results, it is clear that concomitant hydrogen bonding does not strengthen the aryl− amide bond sufficiently to achieve the same stability as the aryl−imine bond. The computed greater stability of the aryl− imine is consistent with the higher TGA stability temperature of 620 °C for the aryl−imine COF relative compared to 500 °C for amCOF reported by Yaghi and co-workers 9 (see the Introduction section). The amCOF structure is covalently reticulated; however, the long linkages between nodes provide large pores.…”

“…This nanochemistry is also a successful paradigm for synthesizing two-dimensional polymers (2DPs), wherein all monomers are assembled into a planar network of covalent bonds and covalent planes are stacked into crystalline order. Since the pioneering contributions of Yaghi and co-workers to create 2DPs, which they referred to as “covalent organic frameworks” (COFs), this proliferating field has been the subject of several reviews. − In this study, we refer to these materials as 2DPs, rather than two-dimensional COFs, as we benchmark their structure and stability relative to conventional linear, 1D polymers. Although many new structures have been realized using nanochemistry, there is very limited evaluation and understanding of 2DPs as mechanically robust, thermally stable materials with dynamic structures.…”

Computational Design and Templated Synthesis of Porous Polyether Frameworks with N and O Adsorption Sites for Efficiently Chelating Heavy Metal Ions

“…Porous organic frameworks (POFs) have been applied popularly in optoelectronic devices, new energy materials, , gas capture, − heavy metal ion removal, and precious metal recovery . In general, geometries of POFs are difficult to tune; moreover, yields of preparation of the POFs are usually low . Theoretical calculation is a green, economical, and effective method to simulate geometries and study the properties of POFs. − Kong et al synthesized hierarchical POF materials based on theoretical calculation for capture and utilization of CO 2 .…”

“…12 In general, geometries of POFs are difficult to tune; 13 moreover, yields of preparation of the POFs are usually low. 13 Theoretical calculation is a green, economical, and effective method to simulate geometries and study the properties of POFs. 14−17 Kong et al synthesized hierarchical POF materials based on theoretical calculation for capture and utilization of CO 2 .…”