Record Complexity in the Polycatenation of Three Porous Hydrogen-Bonded Organic Frameworks with Stepwise Adsorption Behaviors

Abstract

Hydrogen-bonded organic frameworks (HOFs) show great potential in many applications, but few structure–property correlations have been explored in this field. In this work, we report that self-assembly of a rigid and planar ligand gives rise to flat hexagonal honeycomb motifs which are extended into undulated two-dimensional (2D) layers and finally generate three polycatenated HOFs with record complexity. This kind of undulation is absent in the 2D layers built from a very similar but nonplanar ligand, indicating that a slight torsion of ligand produces overwhelming structural change. This change delivers materials with unique stepwise adsorption behaviors under a certain pressure originating from the movement between mutually interwoven hexagonal networks. Meanwhile, high chemical stability, phase transformation, and preferential adsorption of aromatic compounds were observed in these HOFs. The results presented in this work would help us to understand the self-assembly behaviors of HOFs and shed light on the rational design of HOF materials for practical applications.

Halogen‐Bonded Organic Framework (XOF) Based on Iodonium‐Bridged N⋅⋅⋅I+⋅⋅⋅N Interactions: A Type of Diphase Periodic Organic Network

“…Hydrogen‐bonded organic frameworks (HOFs), constructed with building blocks connected by hydrogen bonds, are another type of crystalline porous organic frameworks [5] . Due to the weakness of hydrogen bonds, HOFs are usually less stable than COFs and MOFs, but facile to process and rebuild [6] . Particularly, built based on strong host‐guest interactions, soluble supramolecular organic frameworks (SOFs) represent a unique class porous materials, which exist stably in solution phase while still maintaining periodic structures [7] .…”

Achieving Bright Mechanoluminescence in a Hydrogen-Bonded Organic Framework by Polar Molecular Rotor Incorporation

“…Hydrogen-bonded organic frameworks (HOFs), as an emerging class of multifunctional porous materials, are constructed by discrete organic units through hydrogen-bonding interactions, which can be further stabilized by π•••π interactions, van der Waals interactions, and other weak intermolecular interactions [1][2][3][4] . HOFs show promising applications in such as gas separation, catalysis, biological and optical but suffer from porous instability due to weak noncovalent interactions [5][6][7] .…”

Construction of Two Stable Co(II)-Based Hydrogen-Bonded Organic Frameworks as a Luminescent Probe for Recognition of Fe3+ and Cr2O72− in H2O

“…HOFs have attracted a significant deal of attention especially because of their broad applications, ranging from chemical sensing [ 6 ] and bioimaging [ 7 , 8 ] to lighting [ 9 ] and 3D optical storage [ 10 , 11 ]. The metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) are usually connected by coordination bonds or covalent bonds between atoms and show relatively high stabilities [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], while the HOFs are linked by weak non-covalent interactions, such as hydrogen bonds and π−π stacking interactions, and exhibit relatively low stabilities [ 21 , 22 , 23 , 24 , 25 ]. For HOFs, the solvent guests play important roles in the construction of the supermolecular network system.…”