CO2‑Derived Synthesis of Hydrogen-Bonded Organic Framework Films

We synthesized a hydrogen-bonded organic framework (HOF) built from a CO2-derived 4,4′,4″,4‴-(1,4-phenylenebis­(methanetriyl))­tetrakis­(piperazine-1-carbaldehyde). Single-crystal X-ray analysis revealed a two-dimensional network with a sql topology, and the HOF exhibited permanent porosity with a BET surface area of 315 m2 g–1 and high solution processability. The spin-coating process enabled the fabrication of a homogeneous film with a controllable thickness depending on the concentration of the precursor solutions. The film showed an in-plane proton conductivity of 6.2 × 10–3 S·cm–1 and an activation energy of 0.13 eV under 30 °C, 95% relative humidity.