Terphen[n]arenes and Quaterphen[n]arenes (n=3-6): One-Pot Synthesis, Self-Assembly into Supramolecular Gels, and Iodine Capture.

Abstract

Herein, two new classes of macrocyclic compounds, terphen[n]arenes (TPns) (n=3-6) and quaterphen[n]arenes (QPns) (n=3-6), were designed and synthesized by a one-step condensation reaction in relatively high yields. They comprise 2,2''-dimethoxy terphenyl and 2,2'''-dimethoxy quaterphenyl monomers, respectively, linked by methylene bridges. Given their long and rigid monomers, TPns and QPns have much larger cavities and better self-assembly properties than classic macrocycles. More interestingly, the cyclic pentamers and hexamers TP5, TP6, QP5, and QP6 formed supramolecular organogels, which were composed of interwoven fibers, nanosheets, or entangled macropore networks formed by multiple face-to-face and edge-to-face π⋅⋅⋅π stacking interactions. The xerogel materials effectively captured volatile iodine, not only in aqueous media but also in the gaseous state, and could be recycled multiple times without obvious loss in performance.