Near-Perfect Purification of 2,6-Xylenol from Ternary Cresol Mixtures Using Cucurbit[7]uril

The separation of m -cresol ( m -cre), p -cresol ( p -cre), and 2,6-xylenol (2,6-xyl) poses a significant challenge in industrial processes. This study focuses on selectively separating m -cre and p -cre from a ternary mixture using a cucurbit[7]uril (Q[7]) aqueous solution to achieve the near-perfect purification of 2,6-xyl. Experimental results show that m -cre and p -cre can be selectively encapsulated by the Q[7] host, while 2,6-xyl, due to its larger volume, cannot be encapsulated. The synergistic effect of steric hindrance and complex stability contributes to effective host–guest selective encapsulation separation. The Q[7] aqueous solution can be easily recovered and reused without a significant decrease in separation performance. In the simulated industrial separation experiment, the purity of the purified cresol reached 100%. This research underscores the importance of macrocyclic host molecules in enhancing industrial separations and reducing energy costs through precise guest molecule recognition.