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This study shows the multistep synthesis of a series of Tröger's base polymers of intrinsic microporosity (TB-PIMs) based on a hexaphenylbenzene (HPB) core, with a focus on evaluating their thermal stability, porosity, and CO 2 capture performance. Both ladder and linear structures were prepared, designed to feature tunable nitrogen content and porosity. Our findings demonstrate that polymers with higher nitrogen content, such as tetra-TB-HPB, exhibit superior CO 2 affinity and selectivity, attributed to enhanced interactions with CO 2 and optimized micropore sizes. Linear TB-polymers 1 and 2 are also made for comparison and show competitive performance in carbon capture, suggesting that cost-effective, simpler-to-synthesize materials can achieve efficient gas separation. The study reveals that increased porosity significantly enhances CO 2 capacity and selectivity, particularly in networked TB-HPB-PIMs with high surface areas and narrow micropores, achieving values up to 544 m 2 g -1 , CO 2 uptake of 2.00 mmol g -1 , and CO 2 /N 2 selectivity of 45.6. The thermal properties of these materials, assessed via thermogravimetric analysis (TGA), show that TB-HPB-PIMs maintain robust thermal stability in nitrogen atmosphere, with tetra- and hexa-TB-HPBs leading the series. However, in oxidative environments, denser polymers such as TB-HPB and linear TB-polymer 1 demonstrate higher performance, likely due to restricted air diffusion. Overall, our findings highlight the critical need to balance porosity and thermal stability in TB-HPB-PIMs for applications in gas separation, carbon capture, and the potential for these polymers as flame retardant materials. Tetra-TB-HPB stands out as the most promising material for CO 2 capture and thermal stability under inert conditions, while denser polymers like TB-HPB offer superior performance in oxidative environments.

Most of the reported covalent organic frameworks (COFs) so far are prepared from highly symmetric building blocks, which to some extent limits the expansion of COF diversity and complexity. Low‐symmetric building blocks can be designed through a desymmetrized vertex strategy, which might be used to construct new topological COFs. But reports of COFs constructed by asymmetric building blocks are thus far very rare. Here, a feasible strategy to design asymmetric building blocks for COF synthesis is introduced, by simply varying the positions of functional groups in the monomer. As a proof of concept, two isomeric hexaphenylbenzene‐based "two‐in‐one" type monomers (1,2,4‐HPB‐NH2 and 1,3,5‐HPB‐NH2) are designed and synthesized. To the authors' surprise, self‐polycondensation of the asymmetric 1,2,4‐HPB‐NH2 (i.e., the isomer of common C3‐symmetric 1,3,5‐HPB‐NH2) also affords highly crystalline COF (1,2,4‐HPB‐COF) similar to the symmetric 1,3,5‐HPB‐NH2 counterpart with identical topological structure. The triangular porous structures of both HPB‐based COFs are well resolved by powder X‐ray diffraction (PXRD), theoretical simulations, nitrogen sorption, and morphologies analysis. This work demonstrates the "two‐in‐one" type asymmetric building blocks can also produce highly crystalline frameworks and thus provides a new structural design strategy for reticular chemistry. [ABSTRACT FROM AUTHOR]

Abstract Most of the reported covalent organic frameworks (COFs) so far are prepared from highly symmetric building blocks, which to some extent limits the expansion of COF diversity and complexity. Low‐symmetric building blocks can be designed through a desymmetrized vertex strategy, which might be used to construct new topological COFs. But reports of COFs constructed by asymmetric building blocks are thus far very rare. Here, a feasible strategy to design asymmetric building blocks for COF synthesis is introduced, by simply varying the positions of functional groups in the monomer. As a proof of concept, two isomeric hexaphenylbenzene‐based “two‐in‐one” type monomers (1,2,4‐HPB‐NH2 and 1,3,5‐HPB‐NH2) are designed and synthesized. To the authors’ surprise, self‐polycondensation of the asymmetric 1,2,4‐HPB‐NH2 (i.e., the isomer of common C3‐symmetric 1,3,5‐HPB‐NH2) also affords highly crystalline COF (1,2,4‐HPB‐COF) similar to the symmetric 1,3,5‐HPB‐NH2 counterpart with identical topological structure. The triangular porous structures of both HPB‐based COFs are well resolved by powder X‐ray diffraction (PXRD), theoretical simulations, nitrogen sorption, and morphologies analysis. This work demonstrates the “two‐in‐one” type asymmetric building blocks can also produce highly crystalline frameworks and thus provides a new structural design strategy for reticular chemistry.

The Friedel‐Crafts acylation of hexaphenylbenzene is reported, and the reaction favorably provides the monoacylated products 1 a and 1 b. The resulting ketones 1 a and 1 b are used as precursors for the formation of [5]cumulenes, including 6 b in which the sterically demanding HPB moiety affords a diethynyl[5]cumulene that features significant stability (persistence) versus the analog 6 c which lacks the HPB endgroups. The unsymmetrical substitution pattern of the two most soluble derivatives 6 b and 6 c, allows for estimation of rotational barriers for diethynyl[5]cumulenes via VT NMR studies of cis‐trans isomerization. For both molecules, the barrier to rotation is ca. 15 kcal mol−1, which is attenuated in comparison to other [5]cumulenes due to the presence of the ethynyl endgroups. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of a series of rylene‐diimide substituted hexaphenylbenzenes (HPBs) is presented. The direct connection of the rylene‐diimide units to the HPBs via the imide‐N‐position without any linkers as well as the use of naphthalene‐diimides (NDIs) next to perylene‐diimides (PDIs) is unprecedented. While mono‐substituted products were obtained by imidization reactions with amino‐HPB and the respective rylene‐monoimides, key step for the formation of tri‐ and hexa‐substituted HPBs is the Co‐catalysed cyclotrimerization. Particular emphasis for physic‐chemical characterization was on to the number of NDIs/PDIs per HPB and the overall substitution patterns. Lastly, Scholl oxidation conditions were applied to all HPB systems to generate the corresponding hexa‐peri‐hexabenzocoronenes (HBCs). Importantly, the efficiency of the transformation strongly depends on the number of NDIs/PDIs. While three rylene‐diimide units already hinder the Scholl reaction, the successful synthesis of mono‐substituted HBCs is possible. [ABSTRACT FROM AUTHOR]

In this work, two tailor-made luminogens comprising of electron donors (acridine and phenoxazine) and acceptor (triazine) bridged by the through-space conjugated hexaphenylbenzene (HPB) are synthesized and characterized. Their thermal stability, electrochemical behaviors, crystal, and electronic structures, and photophysical properties are systematically investigated. The crystal and electronic structures reveal that the peripheral phenyls in HPB are closely aligned in a propeller-like fashion, rendering efficient through-space charge transfer between donor and electron moieties. These molecules display weak fluorescence with negligible delayed component in solutions but strong fluorescence with greatly increased delayed component upon aggregate formation, namely aggregation-induced delayed fluorescence (AIDF). Their neat films exhibit high photoluminescence quantum yields (PLQY), and prominent delayed fluorescence. The non-doped organic light-emitting diodes (OLEDs) based on these new luminogens exhibit excellent performance with maximum external quantum efficiency of 12.7% and very small efficiency roll-off of 2.7% at 1,000 cd m−2. Designing AIDF molecules with through-space charge transfer could be a promising strategy to explore robust luminescent materials for efficient non-doped OLEDs.

Crafting of chiral plasmonic nanostructures is extremely important and challenging. DNA‐directed organization of nanoparticle on a chiral template is the most appealing strategy for this purpose. Herein, we report a supramolecular approach for the design of DNA‐decorated, helically twisted nanoribbons through the amphiphilicity‐driven self‐assembly of a new class of amphiphiles derived from DNA and hexaphenylbenzene (HPB). The ribbons are self‐assembled in a lamellar fashion through the hydrophobic interactions of HPB. The transfer of molecular chirality of ssDNA into the HPB core results in the bias of one of the chiral propeller conformations for HPB and induces a helical twist into the lamellar packing, and leads to the formation of DNA‐wrapped nanoribbons with M‐helicity. The potential of the ribbon to act as a reversible template for the 1D chiral organization of plasmonic nanomaterials through DNA hybridization is demonstrated. [ABSTRACT FROM AUTHOR]

The hexakis-alkoxy substituted hexa-peri-hexabenzocoronene (HBC) discotic core is desirable aiming at strong π-π interactions in columns, electronic tuning of the core and better processability. The feasibility of synthesising a new hexakis-alkoxy substituted HBC core is investigated and described in this report. Experimentally, it has been found that when two alkoxy substituents in a peripheral aromatic ring are placed meta to each other, the Scholl reaction results in fully cyclised HBC product. Surprisingly, when the alkoxy groups are ortho to each other, cyclodehydrogenation results in the formation of a partially fused product. This partially-fused ring formation happens under varying reaction conditions and irrespective of the differing alkyl chain lengths. Most plausibly, the considerable strain in the fully fused molecule from 1,2 isomer is the reason to cease the reaction at the partially fused stage. Further quantum-mechanical calculations at the B3LYP/6-31G(d) level of theory also support the hypothesis. The incorporation of two electron donating groups has also reduced the band gap compared to its mono alkoxy analogue. Reduced band gap values are promising feature of these molecules for finding future applications of discotic liquid crystals in organic electronics. [ABSTRACT FROM AUTHOR]

Abstract Hexaphenyl- (1) and hexathienyl-benzene (2) complexes with the six redox-active Cp*(dppe)Fe-C≡C- units are synthesized and their properties in terms of molecular junction are investigated. Both complexes show stepwise multi-redox processes and IVCT bands in the NIR region upon progressive oxidation from the neutral to hexacationic state, as a result of intramolecular electron transfer processes via troidal conjugation through the peripheral aromatic rings. Judging from the V ab values obtained by deconvolution analysis, electronic interaction for thienylene derivative 2 turns out to be stronger than that for the phenylene complex 1. DFT analysis of model complexes support superio'r electron transfer properties for the thienyl derivatives. Graphical abstract Image 1 Highlights • Synthesis of hexaphenyl- and hexathienyl-benzene complexes bearing the six peripheral redox-active Cp*(dppe)Fe-C≡C- termini. • Communication between the peripheral iron centers through toroidal conjugation as analyzed by electrochemistry and IVCT bands. • A DFT study of the model complexes supports the stronger toroidal conjugation for the hexathienyl complex. [ABSTRACT FROM AUTHOR]

Methods for the synthesis of pyrrolo[3,2-b]pyrroles containing hexaphenylbenzene moieties at the 2- and 5-positions or the 1- and 4-positions have been developed. It was shown that placing a hexaphenylbenzene moiety at the 2- and 5-positions requires a Diels-Alder reaction between an alkyne-substituted pyrrolopyrrole core and a 2,3,4,5-tetraphenylcyclopenta-2,4-dien-1-one. The resulting dyes show a strong blue fluorescence that was hypsochromically shifted by chlorination at the 3- and 6-positions. The overall conjugation between the hexaphenylbenzene moieties and the pyrrolopyrrole core is limited, as evident from their photophysical properties. The hexaphenylbenzene moieties attached to the pyrrolo[3,2-b]pyrrole core could not be transformed into hexa-peri-hexabenzocoronenes through intramolecular oxidative aromatic coupling. [ABSTRACT FROM AUTHOR]

Host-guest chemistry is a functional model in supramolecular chemistry for understanding specific process occurring in biological systems. Herein, we describe a rationally designed giant multiarmed hexaphenylbenzene (HPB)-based supramolecular frameworks which encapsulate a variety of guest molecules in the voids of their crystal lattice through the cooperative interplay of multivalency, noncovalent forces and backbone rigidity. In this connection, pseudo-axially substituted twelvearmed hexaphenylbenzene was synthesized and its molecular entrapping nature was studied by varying number of H-bond donor-acceptor sites in the arms. The per-methyl esterified HPB acted as a cavitand to include nonpolar and polar aprotic guests in its crystal structure via C-H···π, C-H···O and C-H···N interactions. The corresponding amidated HPB showed unprecedented inclusion of ammonia and segregation of the guest molecules according to their polarity in the lattice. Furthermore, this molecular entrapping system has been used to obtain the crystal structure of a hitherto unproven 2-azaallenium intermediate, which had been proposed to be involved in aminomethylation of activated arenes. [ABSTRACT FROM AUTHOR]

A large‐scale selective synthesis of a C2v‐symmetric hexaphenylbenzene (HPB) derivative with three different kinds of substituents on the periphery of HPB was realized using inexpensive reagents. All the reactions were carried out at room temperature or by heating and most materials along the synthetic route could be isolated without chromatographic purification. A large‐scale selective synthesis of a C2v‐symmetric hexaphenylbenzene (HPB) derivative with three kinds of substituents on the periphery of HPB was realized using inexpensive reagents. [ABSTRACT FROM AUTHOR]

Herein we report a propeller-like hexaphenylbenzene-based hydrocarbon material (denoted as BT) as the stationary phase for capillary gas chromatography (GC). The statically-coated BT capillary column showed a high column efficiency of 4340 plates m −1 and weak polarity. Owing to its unique conformation, π-electron toroidal delocalization and intrinsic microporosity, the BT stationary phase exhibited interesting selectivity for aromatic compounds over alkanes. Compared with the graphene (G) column, the BT column showed much prolonged retention and high selectivity for aromatic isomers, especially methylnaphthalenes, dimethylnaphthalenes and phenanthrene/anthracene, mainly because of its propeller-like conformation with rich intercalation effects. Moreover, it exhibited good column repeatability (intra-day, inter-day) and reproducibility (between-column) with RSD values on the retention times less than 0.08% for intra-day, 0.32% for inter-day and 3.8% for between-column, respectively. Also, it showed good potential for determination of minor isomer impurities in real samples. To the best of our knowledge, this work presents the first example of employing an neat aromatic hydrocarbon material as the GC stationary phase with high selectivity for analytes of a wide ranging polarity. [ABSTRACT FROM AUTHOR]

We have developed effective reaction conditions for the Suzuki cross-coupling of chlorinated hexaphenylbenzene derivatives. A chloro group on a hexaphenylbenzene framework exhibits a low reactivity to Suzuki cross-coupling, and only nickel catalysts bearing alkyl-substituted phosphine ligands achieved the coupling. With this as a key step, we succeeded in the selective preparation of a C2v-symmetric hexaphenylbenzene derivative containing two kinds of aryl group. [ABSTRACT FROM AUTHOR]

In recent years, low-bandgap polymers have attracted much attention in a wide range of fields. The synthesis of these compounds has been focused on three factors according to the Roncali bandgap theory: 1) the degree of bond-length alternation ( Eδr), 2) the aromatic resonance energy of the cycle ( ERes), and 3) the substituted groups ( ESub). Herein, we have designed and prepared low-bandgap polymers in a different way by using the factors Eθ (the deviation from planarity of the polymer chain) and EInt (the interaction of the molecular chains in the solid state). Thus, three polycyclic aromatic hydrocarbons with different spatial constructions, based on hexaphenylbenzene derivatives, were prepared in this work: linear ( P1-OX), V ( P2-OX), and zigzag ( P3-OX) types. These well-defined polymers exhibited interesting optical and electrochemistry behavior due to their different extents of planarity. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry gave the incremental orderly molecular weight distributions of P1, P2, and P3, the weight-average molecular weights ( [ABSTRACT FROM AUTHOR]

Hexaphenylbenzene (HPB) appended rhodamine derivative 4 has been synthesized which exhibits aggregation-induced emission enhancement (AIEE) characteristics and forms fluorescent aggregates in mixed aqueous media. These aggregates show remarkable fluorescence resonance energy transfer (FRET) in the presence of Hg 2+ ions among various metal ions tested. Further these aggregates were also utilized for the ratiometric imaging of Hg 2+ ions in MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

Hexaphenylbenzene based derivative 7 has been synthesized which formed spherical aggregates in mixed aqueous media. These aggregates exhibited an “on–on” response towards Zn2+ ions in aqueous media. Further, this sensing event was accompanied by the modulation of the self-assembly of aggregates from spherical structures to microrods in aqueous media. This in situ prepared 7-Zn2+ ensemble was utilized as a “not quenched” probe for the selective and sensitive detection of PPi ions in aqueous media. In addition, based upon the fluorescent signals of derivative 7 as outputs (λem = 450 and 370 nm) in the presence of chemical inputs (Zn2+ and PPi), we developed a combinatorial logic circuit with INHIBIT and AND gates. [ABSTRACT FROM AUTHOR]

An improved 12-step synthetic route and full characterization of hexaphenyl-carbo-benzene (4, 8%) and the p-bis-3,5-di-tert-butylphenyl homologue (11, 4%), are described. The carbo-benzene reference 4 is now accurately described in the crystal state by X-ray diffraction analysis in the chiral space group P212121, and in comparison to the less symmetric derivative 11 exhibiting a centro-symmetric packing. According to cyclic voltammetry, both hexaaryl-carbo-benzenes 4 and 11 can behave as both reversible potent electron acceptors and standard electron donors, with respective potentials of −0.73 ± 1 V and +1.17 ± 2 V/SCE, respectively. Due to their extremely low solubility, solid films of 11 fabricated using the “wet method”, with the initial view of studying charge transport properties, were found to display high roughness. [ABSTRACT FROM AUTHOR]

A series of luminescent bis-cyclometalated gold(III) complexes with different nuclearities and various alkynyl ligands derived from hexaphenylbenzene (HPB) and hexabenzocoronene (HBC) have been synthesized. The energies of the low-energy metal-perturbed intraligand (IL) π-π*(R−C^N^C) absorptions of the HPB-alkynyl gold(III) complexes have been fine-tuned by attaching various substituent groups to the bis-cyclometalating ligands. Similarly, the metal-perturbed 3IL [π→π*(R−C^N^C)] emissions of the complexes show energy shifts according to the electronic nature of the bis-cyclometalating ligands. On the contrary, the absorption and emission spectra of the HBC-alkynyl gold(III) complex have been assigned as dominated by the IL transitions of the HBC-alkynyl unit, as supported by transient absorption studies. The supramolecular assembly morphologies of the gold(III) complexes have been studied by TEM and SEM, along with comparisons across different complexes based on the molecular structures, and their assembly processes monitored by concentration-dependent and variable-temperature 1H NMR spectroscopy studies. [ABSTRACT FROM AUTHOR]

A novel polyphenolic backbone, hexakis{4-[(4′-hydroxybiphenyl-4-yl)ethynyl]phenyl}benzene, was synthesised using a common synthetic protocol used for the synthesis of similar polyphenolic compounds.

A shape-persistent polyphenylene with a "spoked wheel" structure was synthesized as a subunit of an unprecedented two-dimensional polyphenylene that we name graphenylene. The synthesis was carried out through a sixfold intramolecular Yamamoto coupling of a dodecabromo-substituted dendritic polyphenylene precursor, which had a central hexaphenylbenzene unit as a template. Characterizations by NMR spectroscopy and matrix-assisted laser ionization time-of-flight mass spectrometry provided an unambiguous structural proof for the wheel-like molecule with a molar mass of 3815.4 g/mol. Remarkably, scanning tunneling microscopy visualization clearly revealed the defined spoked wheel structure of the molecule with six internal pores. [ABSTRACT FROM AUTHOR]

Molecules incorporating with multiple electro-active chromophores are actively sought owing to their potential to serve as energy- and charge-transport materials in the area of photovoltaics and energy storage devices. Herein we demonstrate that a hexaphenylbenzene derivative with six circularly-arrayed electroactive chromophores exhibits effective (toroidal) electronic coupling amongst the six benzophenone moieties. The hexaphenylbenzene-based monobenzoyl ppbBP and hexabenzoyl HBP afford the stabilization of triplet exciton by 4–5 kcal/mol, as compared to parent benzophenone, due to the formation of intramolecular exciplexes with the hexaphenylbenzene propeller. The HBP anion radical, generated by photoinduced electron transfer from a hindered tertiary amine, showed the presence of an intense charge-resonance transition, which was absent in the model compounds (such as ppbBP anion radical). The charge-resonance transition in HBP − evidences delocalization of an electron by hopping over six identical circularly-arrayed benzophenone moieties, which is highly reminiscent of the hole delocalization observed earlier in a number of hexaarylbenzene cation radicals. [ABSTRACT FROM AUTHOR]

Hexaphenylbenzene (HPB) and hexa-peri-hexabenzocoronene-(HBC) functionalised 1,2,3-triazoles have been synthesised using an optimised copper(i)-catalysed azide–alkyne cycloaddition (CuAAC) reaction. The coordination chemistry of these ligands was explored through the synthesis of the respective palladium(ii) complexes and their activity as catalysts in the Suzuki–Miyaura reaction assessed. [ABSTRACT FROM AUTHOR]

The effective and safe capture and storage of radioactive iodine (129I or 131I) is of significant importance during nuclear waste storage and nuclear energy generation. Here we present detailed evidence of highly efficient and reversible iodine capture in hexaphenylbenzene-based conjugated microporous polymers (HCMPs), synthesized via Buchwald-Hartwig (BH) cross-coupling of a hexakis(4-bromophenyl)benzene (HBB) core and aryl diamine linkers. The HCMPs present moderate surface areas up to 430 m² g-1, with narrow pore size distribution and uniform ultramicropore sizes of less than 1 nm. Porous properties are controlled by the strut lengths and rigidities of linkers, while porosity and uptake properties can be tuned by changing the oxidation state of the HCMPs. The presence of a high number of amine functional groups combined with microporosity provides the HCMPs with extremely high iodine affinity with uptake capacities up to 336 wt %, which is to the best of our knowledge the highest reported to date. Two ways to release the adsorbed iodine were explored: either slow release into ethanol or quick release upon heating (with a high degree of control). Spectral studies indicate that the combination of microporosity, amine functionality, and abundant π-electrons ensured well-defined host-guest interactions and controlled uptake of iodine. In addition, the HCMPs could be recycled while maintaining 90% iodine uptake capacity (up to 295%). We envisage wider application of these materials in the facile uptake and removal of unwanted oxidants from the environment. [ABSTRACT FROM AUTHOR]

A supramolecular ensemble having Ag@Cu2O core–shell nanoparticles stabilized by aggregates of a hexaphenylbenzene derivative has been developed which exhibits excellent photocatalytic efficiency in reactions involving preparation of imidazole and benzimidazole derivatives via C–H activation. [ABSTRACT FROM AUTHOR]

A new difluoride monomer containing an aliphatic bridge between 2,6-difluoropheyl and hexaphenylbenzene is designed and synthesized. Then, a series of novel hexa-sulfonated poly(aryl ether ketone)s (HS-PAEK-x) containing an aliphatic spacer between hydrophobic poly(aryl ether ketone)s main chain and hydrophilic sulfonated hexaphenylbenzene are prepared from the new difluoride monomer with 4,4′-(hexafluoroisopropylidene) diphenol and 4,4′-difluorobenzophenone by nucleophilic polycondensation, and subsequent postsulfonation using chlorosulfonic acid. All the polymers give tough, flexible, and transparent membranes by solvent casting. The membranes with comparatively low ion exchange capacity (IEC) values ranging from 0.87 to 1.42 meq g −1 , achieve good mechanical properties, suitable proton conductivity (111 mS cm −1 ) compared with Nafion 117 at 80 °C, and excellent dimensional stability (the highest swelling ratio of length is 9.2% at 80 °C). Furthermore, compared with the previous reported polymers with similar main chain, such as the polymer with pendant sulfoalkyl groups and hollow aromatic hexa-sulfonated polymer, the HS-PAEK-x exhibit higher proton conductivities at similar IEC level, which attributes to the specific molecular structure and improving morphology. Overall, all of the above-mentioned results indicate that the HS-PAEK-x membranes are good candidate materials for proton exchange membranes (PEMs). [ABSTRACT FROM AUTHOR]

Gel formation without chemical cross-links requires strong physical bonds, as observed in diverse molecular and macromolecular systems or supramolecular assemblies above a critical concentration. Here, we present a new molecular amphiphile of propeller-like hexaphenylbenzene derivative bearing two short poly(ethylene glycol) (PEG) chains which forms reversible physical gels comprising long (~2.2 µm) bundles of hydrogel fibrils in coexistence with spherical micelles. Combination of topological (entanglement-like) interactions between the fibers and specific hydrophobic interactions due to the helicity of the PEG chains is proposed to account for the hydrogelation in the semidilute regime. The present supramolecular hydrogels, which are based on small molecules, exhibit extraordinary properties with an exceptionally strong dependence of the shear modulus on concentration, akin to the behavior of ultrahigh molecular weight cellulose-based fibers. [ABSTRACT FROM AUTHOR]

An expanded triptycene (hexaphenylbenzene based triptycene) monomer was synthesized from triiodotriptycene. Using this monomer, two kinds of organic microporous polymers HTP s ( HTP-A and HTP-B ) were prepared by Friedel–Crafts and Scholl reactions. Their structure and properties were characterized by FT-IR, solid 13 C NMR, powder XRD, SEM, TEM and gas absorption. Nitrogen sorption analysis displayed that the BET surface areas are 569 and 914 m 2 g −1 for HTP-A and HTP-B , respectively. For HTP-B , they can reversibly absorb 1.09 wt % H 2 (1.0 bar and 77 K) and 10.3 wt% CO 2 (1.0 bar and 273 K), respectively. [ABSTRACT FROM AUTHOR]

The electronic properties of nine different hexaarylbenzene molecules substituted by sandwich compounds have been studied by applying density functional theory. Different structures and the particular electron donor power of these systems have been considered in order to analyze their oxidant capacity, using bis(ciclopentadienyl) scandium, ferrocene, and bis(benzene)chromium as sandwich compounds. Both monometallic and bimetallic combinations are investigated. According to the ionization energies and electron affinities, compounds with Cr are nucleophiles and represent the best electron donors, whereas compounds with Sc are electrophiles and represent the best electron acceptors. The worse electron donor or acceptor is hexakis(4-ferrocenyl phenyl) benzene. This is very significant, as it implies that the very well-known electronic properties of hexakis(4-ferrocenyl phenyl) benzene can be improved by substituting with other metals, such as Sc and Cr. This suggests several possible applications for these compounds. [ABSTRACT FROM AUTHOR]

Supramolecular aggregates of hexaphenylbenzene derivative 2 exhibit aggregation induced emission enhancement and modulation of self-assembled architecture from spherical to flower-like assembly in the presence of H2S. Furthermore, probe 2 displays higher photostability, low toxicity and bright green fluorescence in two-photon microscopy (TPM) imaging for the detection of H2S in live HeLa cells. [ABSTRACT FROM AUTHOR]

With propeller-like shape, hexaphenylbenzene bromides display different recognition abilities for guest molecules in solid state. HBH can encapsulate CH2Cl2 or Et2O molecules selectively from different solvent systems. For DBH, the recognition pattern is dominated between themselves. In CH2Cl2/toluene/Et2O system, toluene molecule can be encapsulated selectively by MBH. In these supramolecular assemblies, bromine bonding plays an important role. [ABSTRACT FROM AUTHOR]

Aromatic polyimides (PIs) with a hexaphenylbenzene unit were synthesized from 1,4-bis[4-(4-aminophenoxy)phenyl]-2,3,5,6-tetraphenylbenzene (1) and various tetracarboxylic dianhydrides by a conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone and subsequent thermal cyclic dehydration. The PIs were characterized by X-ray diffraction, differential scanning calorimetry, thermogravimetry, and dynamic mechanical analysis. The PIs had glass transition temperatures in the range of 289–352°C, and all the polymers were amorphous. The structure–property relationships of these PIs were examined and compared with those of the previously prepared analogous PIs from 4,4′-bis(4-aminophenoxy)biphenyl (2) and 4,4′-bis(4-amino-2-phenylphenoxy)biphenyl (3). Water absorption and dielectric constants of the PIs were also compared and discussed on the basis of imide content per repeating unit. [ABSTRACT FROM AUTHOR]

A novel polyphenolic backbone, hexakis{4-[(4'-hydroxybiphenyl-4- yl)ethynyl]phenyl}benzene, was synthesised using a common synthetic protocol used for the synthesis of similar polyphenolic compounds. [ABSTRACT FROM AUTHOR]