Substituent Effects on the Gas Sorption and Selectivity Properties of Hexaphenylbenzene and Hexabenzocoronene Based Porous Polymers

Diels-Alder Cycloaddition with CO, CO2, SO2, or N2 Extrusion: A Powerful Tool for Material Chemistry

Phenyl, naphthyl, polyarylphenyl, coronene, and other aromatic and polyaromatic moieties primarily influence the final materials' properties. One of the synthetic tools used to implement (hetero)aromatic moieties into final structures is Diels-Alder cycloaddition (DAC), typically combined with Scholl dehydrocondensation. Substituted 2-pyranones, 1,1-dioxothiophenes, and, especially, 1,3-cyclopentadienones are valuable substrates for [4 + 2] cycloaddition, leading to multisubstituted derivatives of benzene, naphthalene, and other aromatics. Cycloadditions of dienes can be carried out with extrusion of carbon dioxide, carbon oxide, or sulphur dioxide. When pyranones, dioxothiophenes, or cyclopentadienones and DA cycloaddition are aided with acetylenes including masked ones, conjugated or isolated diynes, or polyynes and arynes, aromatic systems are obtained. This review covers the development and the current state of knowledge regarding thermal DA cycloaddition of dienes mentioned above and dienophiles leading to (hetero)aromatics via CO, CO2, or SO2 extrusion. Particular attention was paid to the role that introduced aromatic moieties play in designing molecular structures with expected properties. Undoubtedly, the DAC variants described in this review, combined with other modern synthetic tools, constitute a convenient and efficient way of obtaining functionalized nanomaterials, continually showing the potential to impact materials sciences and new technologies in the nearest future.

Power generation by reverse electrodialysis in a single-layer nanoporous membrane made from core-rim polycyclic aromatic hydrocarbons

Nanoporous graphene and related atomically thin layered materials are promising candidates in reverse electrodialysis research owing to their remarkable ionic conductivity and high permselectivity. The synthesis of atomically thin nanoporous membranes with a narrow pore size distribution, however, remains challenging. Here, we report the fabrication of nanoporous carbon membranes via the thermal crosslinking of core-rim structured monomers, that is, polycyclic aromatic hydrocarbons. The mechanically robust, centimetre-sized membrane has a pore size of 3.6 ± 1.8 nm and a thickness of 2.0 ± 0.5 nm. When applied to reverse electrodialysis, the nanoporous carbon membrane offers a high short-circuit current with an output power density of 67 W m^-2, which is about two orders of magnitude beyond that of the classic ion-exchange membranes and current prototype nanoporous membranes reported in the literature. Crosslinked and atomically thin porous polycyclic aromatic hydrocarbon membranes therefore represent new scaffolds that will revolutionize the rapidly developing fields of sustainable energy and membrane technology.

Tetraphenylethylene-functionalized hexaphenylbenzene with unique conformation-driven selectivity for gas chromatographic separations

Tetraphenylethylene-functionalized hexaphenylbenzene composed of a neat aromatic hydrocarbon with unique conformation-driven selectivity for gas chromatographic separations.

AIEE Active Donor-Acceptor-Donor-Based Hexaphenylbenzene Probe for Recognition of Aliphatic and Aromatic Amines

In the present investigation, an intramolecular charge transfer (ICT) and aggregation induced emission enhancement (AIEE) active donor-acceptor-donor (D-A-D) system 5 having fumaronitrile as the acceptor and hexaphenylbenzene (HPB) as the donor moieties joined through rotatable phenyl rings has been designed and synthesized that is highly emissive in the solid state and exhibits stimuli-responsive reversible piezochromic behavior upon grinding and heating. Because of its AIEE characteristics, HPB derivative 5 undergoes aggregation to form fluorescent aggregates in mixed aqueous media that exhibit ratiometric fluorescence response toward aliphatic amines (primary/secondary/tertiary) and turn-off response toward aromatic amines and hence differentiates between them. Further, the solution-coated portable paper strips of derivative 5 showed pronounced and sensitive response toward aromatic and aliphatic amines with a detection limit in the range of picogram and nanogram level, respectively.

A novel graphite-like stacking structure in a discrete molecule and its molecular recognition behavior

Macrocyclic imines containing two hexabenzocoronene planes adopted a unique intramolecular stacking structure, similar to the stacking pattern in natural graphite.

Microporous organic polymers based on tetraethynyl building blocks with N-functionalized pore surfaces: synthesis, porosity and carbon dioxide sorption

We have synthesized nitrogen-rich polymers by copolymerization of tetraethynyl monomers with tris(4-iodophenyl)amine or 4,4′-diiodoazobenzene. Azobenzene-based polymers exhibited excellent CO₂ adsorption selectivity against N₂.

Hexaphenylbenzene and hexabenzocoronene-based porous polymers for the adsorption of volatile organic compounds

Here we report the vapor adsorption properties of two novel hexaphenylbenzene and hexabenzocoronene-based porous polymers which display excellent affinity for organic compounds (up to 100 wt%) and selectivity over water (<1 wt%).

An azine-linked hexaphenylbenzene based covalent organic framework

We report an azine linked covalent organic framework based on hexaphenylbenzene monomer functionalized with aldehyde groups (“HEX-COF 1”, avg. pore size = 1 nm, surface area >1200 m² g⁻¹, sorption capability at 273 K, 1 atm = 20 wt% for CO² and 2.3 wt% for CH₄).

Electrochemically active porous organic polymers based on corannulene

For the first time, porous organic polymers (POPs) based on the smallest buckybowl, corannulene (BB-POPs) have been synthesized.