A quaternary-ammonium-functionalized covalent organic framework for anion conduction

Abstract

Here we report a new anion conducting covalent organic framework (COF). Quaternary ammonium (QA) ions are covalently tethered onto the pore walls of COF 1,3,5-triformylphloroglucinol-o-tolidine (TpBD-Me) through bromination and quaternization. The QA-functionalized COF shows a bicarbonate conductivity of 5.3 mS cm⁻¹ at 20 °C and 27.0 mS cm⁻¹ at 80 °C, accompanied by 3.3 wt% water uptake and <1.0% swelling ratio at 20 °C. This QA-functionalized COF provides a new option for anion conducting materials.