Study on the Morphologies of Covalent Organic Microporous Polymers: the Role of Reaction Solvents

Two-dimensional conjugated microporous polymers (CMPs) composed of alternative phenylene and ethynylene units are synthesized, by cross-coupling polymerization of 1,3,5-triethynylbenzene and 1,3,5-tribromobenzene with various solvents. Our work shows that the morphology of CMPs is greatly affected by the choice of solvents used in synthesis. Sphere, tubular, and plate-like structures are received by using the toluene, p-xylene, and mesitylene solvents, respectively. Our results demonstrate that the morphology of CMPs affects the storage capacity for organic solvents remarkably, with the plate-like CMP showing best performance. This work is expected to provide useful guidance to rationally design CMPs as absorbent materials for organic solvents.