Highly Selective Separation of Minimum-Boiling Azeotrope Toluene/Pyridine by Nonporous Adaptive Crystals of Cucurbit[6]uril.

The production of high purity toluene and pyridine is of significance in both industrial production and synthetic chemistry. The present protocols available to separate toluene/pyridine mixtures are several energy-intensive distillation methods, which are not environmentally friendly and cost-effective. Herein, we provide an energy-efficient and simple adsorptive separation protocol using nonporous adaptive crystals of cucurbit[6]uril (Q[6]). Q[6] crystals separate pyridine from toluene/pyridine mixtures with nearly 100 % purity. Furthermore, removal of the guest from guest-loaded Q[6] leads to the guest-free cucurbit[6]uril, which can be recycled without losing performance.