1,2,4,5-Tetrakis-(4-formylphenyl)benzene is an important organic intermediate to synthetize substituted covalent organic frameworks (COFs), in which molecular building blocks are precisely organized into two-dimensional (2D) layered structures or three-dimensional (3D) networks, which have emerged as a novel class of crystalline organic polymers with inherent porosity and structural periodicity. Owing to the tunable structures and high porosity, COFs have gained great interest and shown promising applications in molecule storage and separation, heterogeneous catalysis, sensing, energy storage, and optoelectronics.
