Selective Molecular Sieving of Chloro and Bromotoluene Isomers by Trianglimine Macrocycle

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.