A Flexible Hydrogen‐Bonded Organic Framework Constructed from a Tetrabenzaldehyde with a Carbazole N−H Binding Site for the Highly Selective Recognition and Separation of Acetone

Abstract

Rational design of hydrogen‐bonded organic frameworks (HOFs) with multiple functionalities is highly sought after but challenging. Herein, we report a multifunctional HOF (HOF‐FJU‐2) built from 4,4′,4′′,4′′′‐(9H‐carbazole‐1,3,6,8‐tetrayl)tetrabenzaldehyde molecule with tetrabenzaldeyde for their H bonding interactions and carbazole N−H site for its specific recognition of small molecules. The Lewis acid N−H sites allow HOF‐FJU‐2 facilely separate acetone from its mixture with another solvent like methanol with smaller pKa value. The donor (D)‐π‐acceptor (A) aromatic nature of the organic building molecule endows this HOF with solvent dependent luminescent/chromic properties, so the column acetone/methanol separation on HOF‐FJU‐2 can be readily visualized.

A Multistimuli Responsive, Flexible Luminescent Framework and Its Applicability in Anticounterfeiting

“…Recently, organic porous crystals (OPCs), which are formed from pure organic small molecules based on intermolecular weak interactions, including hydrogen bonding (H-bonding), van der Waals forces, halogen bonding, and π–π interactions, have attracted great attention due to their special advantages, such as their mild preparation conditions, solution processability, and easy regeneration. − OPCs that are driven by strong H-bonds are referred to as hydrogen-bonded organic frameworks (HOFs). − They are able to maintain permanent channels and have been used in applications such as gas storage and separation, , heterogeneous catalysis, − and molecular recognition. − Among HOFs, photoluminescent HOFs (PL-HOFs) have been proved to be excellent smart materials that can recognize and detect some special molecules, such as organic arsenic, aniline, Fe 3+ , etc. PL-HOFs can also be used as stimuli-responsive materials for encapsulating guests, detecting guest polarity, mechanofluorochromism, − and mechanoluminescence .…”

Enhanced stability and ultrahigh proton conductivity of hydrogen-bonded organic frameworks

“…[20][21][22] Based on these methods, researchers have prepared excellent MOF-/COF-based proton conducting materials with proton conductivity comparable to or even better than the Nafion membrane. 9,23 As the counterparts of MOFs and COFs, hydrogen-bonded organic frameworks (HOFs) have recently shown great potential in proton conduction, 21,[24][25][26][27][28] in addition to gas adsorption, 29,30 gas separation, [31][32][33][34][35][36][37] catalysis, [38][39][40] molecular recognition, [41][42][43][44] photodynamic therapy 45 and biosensing. [46][47][48] As a kind of crystalline framework material constructed by self-assembly of organic building units mainly through intermolecular hydrogen bonds, HOFs not only have the characteristics of designable structures, high specific surface area and controllable channels, but also have the advantages of mild synthesis conditions, solvent processability, easy healing and regeneration.…”

Photo Responsive Electron and Proton Conductivity within a Hydrogen‐Bonded Organic Framework

“…[14] The flexible nature of HOFs has been also utilized to generate optical properties, exhibiting different luminescent colors by the incorporation of different guest species. [15] During our studies on this emerging multifunctional HOF materials, we came cross the active research topic on multifunctional organic cocrystal materials. We speculate that the extensive research endeavors of scientists and engineers of different expertise among the communities of organic chemistry, crystal engineering, materials science and electronics will not only establish the basic chemistry and principle of such multifunctional organic materials but will also lead to the implementation of some materials for their practical and/or industrial applications.…”