Solvent controlled self-assembly of π-stacked/H-bonded supramolecular organic frameworks from a C3-symmetric monomer for iodine adsorption

Abstract

Controlling the assembly of low-molecular-weight molecules into various well-defined architectures has become a fascinating topic in materials science and supramolecular chemistry. Synchronously, since nuclear power has been rapidly developed as a clean, reliable and cost-effective energy source to meet the growing energy demands, the efficient capture and storage of the produced by-products of radioactive iodine has become extremely important. Here, we presented three supramolecular organic frameworks (SOFs) that assembled from a C₃-symmetric monomer (TPBTCH) via π–π stacking and hydrogen-bonding. These SOFs showed different basic units and structures through tuning the solvent systems. Among the three SOFs, due to its superior perforated porousness as well as N-rich and π-conjugated skeleton, we applied porous JLUE-SOF-3-DMSO in iodine removal, and conducted a detailed investigation of the adsorption behavior. The adsorption data were studied by the theoretical analysis of the adsorption kinetics and adsorption isotherms, and the results fit well to the pseudo-second-order model and the Langmuir isotherm model. In addition, a maximum adsorption capacity of 207 mg g⁻¹ of iodine over JLUE-SOF-3-DMSO at 298 K based on the Langmuir model was achieved.