Structure and Properties of Porous Crystals Based on Hydrogen-Bonded Two-Dimensional Network Structures

Shape-persistent π-conjugated molecules bearing three or more carboxyl groups can form designed porous structures through the formation of robust supramolecular synthons（i.e., hydrogen-bonded dimer）followed by networked structures. In particular, planar hexacarboxylic acids and tetracarboxylic acids yield two-dimensional（2D）network sheets with hexagonal（hxl-）or square lattice（sql-）topologies, respectively. The assembly pattern of these sheets, on the other hand, depends on the core characteristics of the individual molecules. Based on the authors’ recent research, this review introduces the structure, porosity, and optoelectronic properties of hydrogen-bonded organic frameworks（HOFs）based on these 2D networks with distinct topologies.