writer：Y.-L. Zhu, C.-L. Fu, Z.-W. Li, Z.-Y. Sun
keywords：Covalent Organic Frameworks
source：期刊
specific source：J. Phys. Chem. Lett. 2020, 11, 1, 179-183
Issue time：2019年
Polymerization of monomers into two-dimensional covalent organic frameworks with precise porous structures exhibits desired catalytic, gas separation, and optoelectronic properties. However, the defects arising from covalent bonding in polymerization process always result in amorphous films with small crystalline domains or polycrystalline powders. It is still a tremendous challenge to synthesize high quality crystalline products, even single crystals with a large size over micrometer scale. In this work, we propose a general strategy of building block design to reduce the defects during growth of two-dimensional covalent organic frameworks. We demonstrate that the building block with a hexagonal pore unit, i.e. hexamer, could greatly decrease defects by directionally uniform growing in polymerization, while monomer, dimer, and trimer building blocks form more defects due to linear growth. Our work provides a new strategy to construct super-large single crystal in practical applications by combining building block design and growing dynamics control.