Porous hydrogen-bonded organic frameworks (HOFs): From design to potential applications

Hydrogen-bonded frameworks (HOFs), which are constructed from organic moieties via hydrogen bonding, represent an emerging attractive class of porous crystalline materials. Though HOFs have exhibited varieties of merits such as solution processability, highly-crystalline structure, good recyclability, easy purification etc., the flexible and weak feature of hydrogen bonds usually makes the HOFs vulnerable and difficult to maintain the permanent porosity, which greatly hampers the development and application of this kind of materials. In this work, some basic rules to construct HOFs with permanent porosity and good stability are summarized. Moreover, the major applications of HOFs are highlighted in this review, including the gas storage/separation, proton conduction, catalysis, luminescent materials, biotechnology etc. Specifically, some latest developments and discoveries in this area are summarized and discussed. Finally, the promising perspectives of HOFs are also discussed and the potential directions for future work are suggested.