Structural and Morphological Engineering of Benzothiadiazole-Based Covalent Organic Frameworks for Visible Light-Driven Oxidative Coupling of Amines

Abstract

Covalent organic frameworks (COFs) are appealing platforms for photocatalysts because of their structural diversity and adjustable optical band gaps. The construction of efficient COFs for heterogeneous photocatalysis of organic transformations is highly desirable. Herein, we constructed a photoactive COF containing benzothiadiazole and triazine (BTDA−TAPT), for which the morphology and crystallinity might be easily tuned by slight synthetic variation. To unveil the relationship of photocatalytic properties between the structure and morphology, analogous COFs were synthesized by precisely tailoring building blocks. Systematic investigations indicated that tuning the structure and morphology might greatly impact photoelectric properties. The BTDA−TAPT featuring ordered alignment and perfect crystalline nature was more beneficial for promoting charge transfer and separation, which exhibited superior photocatalytic activity for visible light-driven oxidative coupling of amines. Outcomes from this study reveal the intrinsic synergy effects between the structure and morphology of COFs for photocatalysis.

Photocatalytic conversion of arylboronic acids to phenols by a new 2D donor–acceptor covalent organic framework

“…In contrast, COFs are often used as a photocatalytic material because of their good chemical stability and adjustable chemical structure. [17][18][19][20][21][22][23][24] With extended p-conjugated frameworks, excellent stability and adjustable chemical structures, COFs have shown great potential for broad applications in many prospects, such as phototransistors, optoelectronic devices and photocatalytic reactions. [25][26][27][28][29][30][31][32] Recently, reactions like redox, CH functionalization and E/Z isomerization have proved that covalent organic frameworks have great appeal in visible light-driven organic transformations.…”

“…In contrast, COFs are often used as a photocatalytic material because of their good chemical stability and adjustable chemical structure. 17–24…”

Modulating electronic structure of triazine-based covalent organic frameworks for photocatalytic organic transformations

“…Recently, heterogeneous catalysts composed of pure organic compounds, such as carbon nitrides 15 and conjugated microporous polymers (CMPs), [16][17][18][19] have attracted great interest because of their impressive recyclability. Unfortunately, most of these heterogeneous catalysts are amorphous or semicrystalline, 20,21 posing great difficulties in understanding the relationship between structure and performance. Hence, seeking a recyclable, crystalline porous organic polymer as a metal-free photocatalyst is an urgent need.…”

Efficient Photocatalytic Oxidative Coupling of Benzylamine over Uranyl–Organic Frameworks

“…Abundant and inexhaustible solar energy is one of the most embraced environmental energies to drive organic transformation and green synthesis of valuable chemicals. − In the last decade, a vast number of photocatalysts have been developed for a variety of solar-driven organic reactions, especially the direct synthesis of imines. − Imines are essential organic intermediates in the synthesis of many dyes, pharmaceuticals, and fine chemicals. , If these compounds can be synthesized by imines as crude materials, their synthetic routes will be effectively shortened. Therefore, it is of great significance to develop strategies for the direct synthesis of imines.…”