Construction of organic semiconducting materials with in-plane π-conjugated structures and robustness through carbon-carbon bond linkages, alternatively as graphene analogs, is extremely desired for powerfully optoelectrical conversion. However, the poor reversibility sp2 carbon forming reactions makes them unavailable building high crystalline well-defined a self-healing process, such covalent frameworks (COFs). Here we report scalable solution-processing approach to synthesize family...

Establishing an sp2-carbon-bonding pattern is one of the efficient accesses to various organic semiconducting materials. However, less-reversible carbon-carbon bond formation makes it still challenging spatially construct a well-defined framework with π-extended two-dimensional (2D) structure through solution process. Here, Knoevenagel condensation approach synthesize two new 2D covalent frameworks (COFs) connected by unsubstituted double linkages activating methyl carbons...

2D conjugated COF based on olefin (CC) linkages has been readily synthesized using the Knoevenagel condensation reaction.

Abstract Developing effective synthetic strategies as well enriching functionalities for sp 2 ‐carbon‐linked covalent organic frameworks (COFs) still remains a challenge. Now, taking advantage of variant Knoevenagel condensation, new fully conjugated COF ( g‐C 34 N 6 ‐COF ) linked by unsubstituted C=C bonds was synthesized. Integrating 3,5‐dicyano‐2,4,6‐trimethylpyridine and 1,3,5‐triazine units into the molecular framework leads to enhanced π‐electron communication electrochemical activity....

Abstract The polarity of a semiconducting molecule affects its intrinsic photophysical properties, which can be tuned by varying the molecular geometry. Herein, we developed D 3 h ‐symmetric tricyanomesitylene as new monomer could reticulated into vinylene‐linked covalent organic framework (g‐C 54 N 6 ‐COF) via Knoevenagel condensation with another 2,4,6‐tris(4′‐formyl‐biphenyl‐4‐yl)‐1,3,5‐triazine. Replacing C 2 v 3,5‐dicyano‐2,4,6‐trimethylpyridine gave less‐symmetric COF 52 ‐COF)....

Abstract Electrochemically driven carbon dioxide (CO 2 ) conversion is an emerging research field due to the global warming and energy crisis. Carbon monoxide (CO) one key product during electroreduction of CO ; however, this reduction process suffers from tardy kinetics low local concentration on a catalyst's surface density active sites. Herein, presented combination experimental theoretical validation Ni porphyrin‐based covalent triazine framework (NiPor‐CTF) with atomically dispersed NiN...

Vinylene-bridged covalent organic frameworks (COFs) have shown great potential for advanced applications because of their high chemical stability and intriguing semiconducting properties. Exploring new functional monomers available the reticulation vinylene-bridged COFs establishing effective reaction conditions are extremely desired enlarging realm this kind material. In work, a series two-dimensional (2D) synthesized by Knoevenagel condensation tricyanomesitylene with ditopic or tritopic...

Abstract We developed a simple approach to synthesizing ionic vinylene‐linked two‐dimensional covalent organic frameworks (COFs) through quaternization‐promoted Knoevenagel condensation at three aromatic methyl carbon atoms of N ‐ethyl‐2,4,6‐trimethylpyridinium halide with multitopic aldehyde derivatives. The resultant COFs exhibited honeycomb‐like structure high crystallinity and surface areas as large 1343 m 2 g −1 . regular shape‐persistent nanochannels the positively charged polymeric...

Reticular chemistry based on thermodynamically controlled linking modes and numerous organic building blocks has constituted versatile crystalline frameworks in molecular-level precision. However, vinylene-linked covalent (COFs) are still quite far from flexible tailoring either their structures or topologies, due to the lack of monomers with sufficient activities. Herein, we establish a strategy synthesize COFs via Knoevenagel condensation between tetratopic monomer...

Abstract The 3D covalent organic frameworks (COFs) have attracted considerable attention owing to their unique structural characteristics. However, most of COFs interpenetration phenomena, which will result in decreased surface area and porosities, thus limited applications molecular/gas capture. Developing with non‐fold is challenging but significant because the existence non‐covalent interactions between adjacent nets. Herein, a new COF (BMTA‐TFPM‐COF) dia topology for Au ion capture first...

Abstract Polymeric semiconductors are emerging as a kind of competitive photocatalysts for hydrogen evolution due to their well‐tunable structures, versatile functionalization, and low‐cost processibility. In this work, series conjugated porous polymers with substantial cyano‐substituted fully sp 2 ‐carbon frameworks efficiently synthesized by using electron‐deficient tricyanomesitylene key building block promote an organic base‐catalyzed Knoevenagel condensation various aldehyde‐substituted...

Embedding heteroatoms into the main backbones of polymeric materials has become an efficient tool for tailoring their structures and improving properties. However, owing to comparatively harsh heteroatom-doping conditions, this rarely been explored in covalent organic frameworks (COFs). Herein, upon aldol condensation a trimethyl-substituted pyrylium salt with tritopic aromatic aldehyde, two-dimensional oxonium-embedded COF vinylene linkages was achieved, which further converted neutral...

Abstract Developing effective synthetic strategies as well enriching functionalities for sp 2 ‐carbon‐linked covalent organic frameworks (COFs) still remains a challenge. Now, taking advantage of variant Knoevenagel condensation, new fully conjugated COF ( g‐C 34 N 6 ‐COF ) linked by unsubstituted C=C bonds was synthesized. Integrating 3,5‐dicyano‐2,4,6‐trimethylpyridine and 1,3,5‐triazine units into the molecular framework leads to enhanced π‐electron communication electrochemical activity....

Knoevenagel condensation is a powerful tool for the construction of vinylene-linked covalent organic frameworks. Herein, we established concise approach to COFs by at multi-methyl groups pyridine ring through in situ formation an N-acyl pyridinium cation presence various acylating reagents. Following this strategy, two were constructed using 2,4,6-trimethylpyridine and multi-aldehyde-substituted aromatic derivatives as monomers. The resultant are highly crystalline assembled into hexagonal...

A D3h-symmetric hexatopic monomer was first prepared by attaching the three-fold ditopic moiety 2,6-dimethylpyridine to meta-positions of a phenyl ring. It further condensed at its six pyridylmethyl carbons with linear aromatic dialdehydes, resulting in two vinylene-linked COFs heteroporous topologies, as revealed powder X-ray diffraction (PXRD), nitrogen sorption, and pore-size distribution analyses, well transmission electron microscopy (TEM) image. The linear- cross-conjugations,...

Covalent organic frameworks (COFs) have attracted considerable attention as adsorbents for capturing and separating gold from electronic wastes. To enhance the binding capture efficiency, constructing hydrogen-bond nanotraps along pore walls was one of most widely adopted approaches. However, development absorbing skeletons ignored due to weak ability salts (Au). Herein, we demonstrated skeleton engineering construct highly efficiently absorbs Au capture. The strong donating feature...

Abstract Covalent organic frameworks (COFs) have attracted considerable attention as adsorbents for capturing and separating gold from electronic wastes. To enhance the binding capture efficiency, constructing hydrogen‐bond nanotraps along pore walls was one of most widely adopted approaches. However, development absorbing skeletons ignored due to weak ability salts (Au). Herein, we demonstrated skeleton engineering construct highly efficiently absorbs Au capture. The strong donating feature...

Owing to its prominent π-delocalization and stability, vinylene linkage holds great merits in the construction of covalent organic frameworks (COFs) with promising semiconducting properties. However, carbon-carbon double bond formation reaction always exhibits relatively low reversibility, unfavorable for high crystalline through self-error correction assembling processes. In this work, we report a heteroatom-tuned strategy build up series two-dimensional (2D) vinylene-linked COFs by...

Abstract Covalent organic frameworks (COFs) have been utilized as the ideal candidates to preciously construct electrocatalysts. However, highly ordered degree of COFs renders catalytic centers closely stacked, which limits utilization efficiency sites. Herein, we first constructed dangling and staggered‐stacking aldehyde (–CHO) from [4 + 3] for 2e − oxygen reduction reaction (ORR). The new unreacted ‐CHO out COFs' planes, are more easily exposed in electrolytes than sites frameworks. More...

This work reports an efficient strategy to tailor the stacking mode in 2D vinylene-linked covalent triazine frameworks by regulating base-catalyst with different alkali-metal ions.

Owning triply periodic minimal surfaces and three-dimensional (3D) interconnected pores, bicontinuous porous materials have drawn enormous attention due to their great academic interest potential applications in many fields including energy catalysis. However, synthesis has remained a challenge. Here, we demonstrate the of organic semiconductor photocatalyst, which involves preparation SiO2 with shifted double diamond (DD) structure through solvent evaporation-induced self-assembly...

Abstract The polarity of a semiconducting molecule affects its intrinsic photophysical properties, which can be tuned by varying the molecular geometry. Herein, we developed D 3 h ‐symmetric tricyanomesitylene as new monomer could reticulated into vinylene‐linked covalent organic framework (g‐C 54 N 6 ‐COF) via Knoevenagel condensation with another 2,4,6‐tris(4′‐formyl‐biphenyl‐4‐yl)‐1,3,5‐triazine. Replacing C 2 v 3,5‐dicyano‐2,4,6‐trimethylpyridine gave less‐symmetric COF 52 ‐COF)....