A Proton Conductive Porous Framework of an 18-Crown-6-Ether Derivative Networked by Rigid Hydrogen Bonding Modules

A rigid hydrogen-bonded organic framework (HOF) was constructed from a C-3-symmetric hexatopic carboxylic acid with a hydrophilic 18-crown-6-ether (18C6) component. Despite the flexible macrocyclic structure with many conformations, the derivative with three 4,4'-dicarboxy-o-terphenyl moieties in the periphery yielded a rigid layered porous framework through directional intermolecular hydrogen bonding. Interestingly, the HOF possesses 1D channels with bottleneck composed of 18C6 rings. The HOF shows proton conductivity (1.12x10(-7) S cm(-1)) through Grotthuss mechanism (E-a=0.27 eV) under 98 %RH. The present unique water channel structure provides an inspiration to create molecular porous materials.

Automated summary

A rigid hydrogen-bonded organic framework was constructed using a flexible macrocyclic structure and directional intermolecular hydrogen bonding, showing proton conductivity with 1D channels. This unique water channel structure provides inspiration for creating molecular porous materials.