Geminiarene: Molecular Scale Dual Selectivity for Chlorobenzene and Chlorocyclohexane Fractionation.

In this work, a new version of macrocyclic arenes, namely geminiarene, has been designed and synthesized for guest complexation and chlorobenzene/chlorocyclohexane mixture separation with excellent dual selectivity. Due to its unique dual/gemini conformational feature, not only chlorocyclohexane can be separated from chlorobenzene with exceeding 97% purity but also chlorobenzene can be separated from chlorocyclohexane with purity over 88%, and the dual selective fractionation process could be achieved in only one cycle of operation. Significantly, we demonstrate that the dual selectivity capability is essentially a competition of the stability between the guest-free and guest-loaded crystalline phases of geminiarene. We strongly believe that this work and the idea of multiple selective separation systems will open up new perspectives on macrocycle-based solid-state host-guest chemistry and molecular scale separation materials.