Selective Separation of Phenanthrene from Aromatic Isomer Mixtures by a Water-Soluble Azobenzene-Based Macrocycle

Abstract

Selective separation of phenanthrene (PHE) from aromatic isomer mixtures is a big challenge in industry. In this work, a light-responsive water-soluble azobenzene-based macrocycle <b>1</b> is synthesized and an aqueous solution of <i>E</i>,<i>E</i>-<b>1</b> is employed to separate PHE from anthracene via a solid-liquid extraction method under ambient conditions. After five extraction cycles, the average purity for PHE is about 91.1% and macrocycle <b>1</b> can be reused at least five times without obvious reduction of separation performance for PHE. This work not only comprises a new and clean way to separate PHE by taking advantage of a macrocyclic host but also promotes the application of host-guest chemistry.