Topology‐Templated Synthesis of Crystalline Porous Covalent Organic Frameworks

Abstract

Astrategy is presented for the synthesis of crystalline porous covalent organic frameworks via topology-templated polymerization. The template is based on imine-linked frameworks and their (001) facets seed the C = Cb ond formation reaction to constitute 2D sp 2 carbon-conjugated frameworks. This strategy is applicable to templates with different topologies,e nables designed synthesis of frameworks that cannot be prepared via direct polymerization, and creates as eries of sp 2 carbon frameworks with tetragonal, hexagonal, and kagome topologies.T he sp 2 carbon frameworks are highly luminescent even in the solid state and exhibit topologydependent p transmission and exciton migration;t hese key fundamental p functions are unique to sp 2 carbon-conjugated frameworks and cannot be accessible by imine-linked frameworks,a morphous analogues,a nd 1D conjugated polymers. These results demonstrate an unprecedented strategy for structural and functional designs of covalent organic frameworks.

All sp2 carbon covalent organic frameworks

“…By contrast, the [C 2 + C 2 ] scheme with a C 2 -symmetric knot and C 2 -symmetric linker allows the design of two different polygonal structures. One is a rhombic backbone (Figure 1C) and the other is the kagome structure (Figure 1D) [12,[14][15][16][17]23,25]. Kagome COFs usually comprise two different types of pores, hexagonal mesopores and trigonal mesopores or micropores [17].…”

“…One is a rhombic backbone (Figure 1C) and the other is the kagome structure (Figure 1D) [12,[14][15][16][17]23,25]. Kagome COFs usually comprise two different types of pores, hexagonal mesopores and trigonal mesopores or micropores [17]. The [C 3 + C 2 ] diagram with a C 3 -symmetric knot but six reactive sites and a C 2 -symmetric linker allows the design of trigonal skeletons with two different pore sizes (Figure 1E) [19,24,37,38].…”

“…The direct synthesis of sp 2 carbon COFs based on the aforementioned methods usually lead to limited crystallinity and in many cases cannot yield crystalline frameworks. To address this issue, Jiang and colleagues have explored a template strategy to synthesize sp 2 carbon COFs (Figure 4) [17].…”

“…Interestingly, Jiang and colleagues observed that 2D sp 2 carbon COFs are distinct from 1D sp 2 carbon polymers and graphene in terms of their π conjugation and polaron behavior [14]. This finding inspired the synthesis of a diversity of sp 2 carbon COFs with different building blocks and topologies, shaping a molecular platform for the exploration of sp 2 carbon materials [15][16][17][18][19][20][21][22][23][24][25].…”

Unraveling the Effect of Defects, Domain Size, and Chemical Doping on Photophysics and Charge Transport in Covalent Organic Frameworks

“…Additional experiments and simulations are needed to completely characterize the impact of topology on charge migration in 2D-COFs. 89…”