Highly selective removal of heterocyclic impurities from toluene by nonporous adaptive crystals of perethylated pillararene†
The removal of heterocyclic impurities from toluene in the petrochemical industry is necessary but challenging. Herein, we provide a convenient and environmentally friendly adsorptive separation strategy using nonporous adaptive crystals of perethylated pillararene (EtP6). These crystals show a highly selective preference for heterocyclic compounds, and are capable of selectively adsorbing them from a mixture of toluene and heterocyclic compounds, ultimately improving the purity of toluene from 96.78% to 99.00%. Single crystal structures indicate that the selectivity derives from the differences in the structural stability of the guest-loaded EtP6 crystals.