Engineering Functionality in Organic Porous Networks by Multicomponent Polymerization

Developing a simple and efficient methodology to engineer functionality of porous materials is highly desirable due to the significant relationship between functionality and applications. Herein, we report alkynyl imine-containing porous organic polymers (AIPOPs) by a one-pot multicomponent polymerization reaction of tetrabromoarene, isonitrile, and diyne. The introduction of alkynyl imine groups in the porous networks imparts the materials functionality and leads to significantly enhanced iodine adsorption capacity in comparison to an alkynyl-linked comparative porous polymer with higher porosity, evidenced by the iodine capture in vapor. By altering the amount of isonitrile, the content of alkynyl imine groups in the networks is varied and their iodine capture performances are tuned with the maximum adsorption capacity of iodine vapor of 4.10 g g–1, which is comparable to or higher than many iodine adsorbents. The mechanism investigation demonstrates that the adsorption is due to chemisorption, that is, electron transfer from electron-rich units (imine, phenyl rings, and triple bonds) in the adsorbents to I2 with the formation of polyiodides and physisorption. These materials can also remove I2 in n-hexane solutions and the process fits well with the Freundlich model. These results indicate their promising potentials as efficient adsorbents for iodine capture in vapor and solutions. This work represents the first example of amorphous functional porous polymers synthesized by multicomponent reactions and thus may pave a new way for developing porous polymers with intriguing functionality and applications based on the present and more multicomponent reactions.