Polyphosphonate covalent organic frameworks
Ke Xu, Robert Oestreich, Takin Haj Hassani Sohi, Mailis Lounasvuori, Jean G. A. Ruthes, Yunus Zorlu, Julia Michalski, Philipp Seiffert, Till Strothmann, Patrik Tholen, A. Özgür Yazaydın, Markus Suta, Volker Presser, Tristan Petit, Christoph Janiak, Jens Beckmann, Jörn Schmedt auf der Günne, Gündoğ Yücesan
Abstract
Abstract Herein, we report polyphosphonate covalent organic frameworks (COFs) constructed via P-O-P linkages. The materials are synthesized via a single-step condensation reaction of the charge-assisted hydrogen-bonded organic framework, which is constructed from phenylphosphonic acid and 5,10,15,20‐tetrakis[p‐phenylphosphonic acid]porphyrin and is formed by simply heating its hydrogen-bonded precursor without using chemical reagents. Above 210 °C, it becomes an amorphous microporous polymeric structure due to the oligomerization of P-O-P bonds, which could be shown by constant-time solid-state double-quantum 31 P nuclear magnetic resonance experiments. The polyphosphonate COF exhibits good water and water vapor stability during the gas sorption measurements, and electrochemical stability in 0.5 M Na 2 SO 4 electrolyte in water. The reported family of COFs fills a significant gap in the literature by providing stable microporous COFs suitable for use in water and electrolytes. Additionally, we provide a sustainable synthesis route for the COF synthesis. The narrow pores of the COF effectively capture CO 2 .