Selective Molecular Sieving of Chloro and Bromotoluene Isomers by Trianglimine Macrocycle

by Xuanfu Zhu, Gengwu Zhang, Lukman O. Alimi, Basem M. Moosa, Abdul-Hamid Emwas, Fang Fang, Niveen M. Khashab
Year: 2023 DOI: 10.1021/acs.chemmater.3c01888


Chem. Mater. 2023, 35, 21, 9160–9166


The separation of para-halotoluene (PHT) is crucial in the chemical industry. However, due to the similar physical properties of those halotoluene isomers, industrial separation can be time-consuming and energy-intensive. Herein, we present an energy-efficient method for adsorptive separation of PHT, such as para-chlorotoluene and para-bromotoluene, from their trinary isomer mixture using a trianglimine (TI) macrocycle. The selectivity of the separation is dominated by the C–H···π, ···π, and C–H···Cl interactions between the TI macrocycle and captured guest molecule. Moreover, the macrocycle of the molecular sieve exhibits a high degree of recyclability, as it can maintain the performance over multiple cycles. These findings reinforce the viability of using molecular sieves for sustainable chemical separation processes.