Semiconductive microporous hydrogen-bonded organophosphonic acid frameworks

Patrik Tholen,Mehmet Menaf Ayhan,Ceyda Bayraktar,Jens Beckmann,Bünyemin Çoşut,Craig A Peeples,Yunus Zorlu,Raoul Schaper,Gabriel Hanna,Michael Wark,Turan Selman Erkal,A Ozgur Yazaydin,Gündoğ Yücesan

doi:10.1038/s41467-020-16977-0

Abstract

Herein, we report a semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20‐tetrakis[p‐phenylphosphonic acid] porphyrin (GTUB5). The structure of GTUB5 was characterized using single crystal X-ray diffraction. A narrow band gap of 1.56 eV was extracted from a UV-Vis spectrum of pure GTUB5 crystals, in excellent agreement with the 1.65 eV band gap obtained from DFT calculations. The same band gap was also measured for GTUB5 in DMSO. The proton conductivity of GTUB5 was measured to be 3.00 × 10−6 S cm−1 at 75 °C and 75% relative humidity. The surface area was estimated to be 422 m2 g−1 from grand canonical Monte Carlo simulations. XRD showed that GTUB5 is thermally stable under relative humidities of up to 90% at 90 °C. These findings pave the way for a new family of organic, microporous, and semiconducting materials with high surface areas and high thermal stabilities.

Highlights

We report a semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20‐tetrakis[p‐ phenylphosphonic acid] porphyrin (GTUB5)
We present the first example of a HOF, synthesized using phosphonic acid functional groups (R-PO3H2), which exhibits a low band gap, proton conductivity, and high thermal stability
The H8-TPPA linker was synthesized according to our previously reported method involving a Pd-catalyzed Arbuzov reaction[50], in order to avoid the porphyrin core being occupied by Ni(II) after a Ni-catalyzed Arbuzov reaction[49,50]

Summary

Introduction

We report a semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20‐tetrakis[p‐ phenylphosphonic acid] porphyrin (GTUB5). XRD showed that GTUB5 is thermally stable under relative humidities of up to 90% at 90 °C These findings pave the way for a new family of organic, microporous, and semiconducting materials with high surface areas and high thermal stabilities. Stable and permanently microporous semiconducting HOFs could revolutionize the design of supercapacitors and electrodes due to their simpler chemistry compared to MOFs. Thermally stable and permanently microporous semiconducting HOFs could revolutionize the design of supercapacitors and electrodes due to their simpler chemistry compared to MOFs In this communication, we present the first example of a HOF (known as GTUB5, where TUB stands for Technische Universität Berlin and G for Gebze), synthesized using phosphonic acid functional groups (R-PO3H2), which exhibits a low band gap, proton conductivity, and high thermal stability. Given these starting conditions and materials, it is expected that a mixed linker strategy involving H8-TPPA and PPA could produce twodimensional HOFs with hexagonal void channels

Methods

Results

Conclusion