Organic chemistry

Covalent bond

Polymer chemistry

Combinatorial chemistry

Photocatalysis

Crystallography

Surface modification

Catalysis

Physical chemistry

Chemistry

Chemical stability

Thiazole

Crystallinity

Sulfur

Annulation

Photochemistry

Journal of the American Chemical Society

The development of robust synthetic routes to stable covalent organic frameworks (COFs) is important to broaden the range of applications for these materials. We report here a simple and efficient three-component assembly reaction between readily available aldehydes, amines, and elemental sulfur via a C-H functionalization and oxidative annulation under transition-metal-free conditions. Five thiazole-linked COFs (TZ-COFs) were synthesized using this method. These materials showed high levels of crystallinity, high specific surface areas, and excellent physicochemical stability. The photocatalytic applications of TZ-COFs were investigated, and TZ-COF-4 gave high sacrificial hydrogen evolution rates from water (up to 4296 μmol h-1 g-1 under visible light irradiation) coupled with high stability and recyclability, with sustained hydrogen evolution for 50 h.

Synthesis of Stable Thiazole-Linked Covalent Organic Frameworks via a Multicomponent Reaction