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Controllable fabrication of enantiospecific molecular superlattices is a matter of imminent scientific and technological interest. Herein, we demonstrate that long-range superlattice chirality in molecular self-assemblies can be tailored by tuning the interplay of weak intermolecular non-covalent interactions between hexaphenylbenzene-based enantiomers. By means of high-resolution scanning tunneling microscopy measurements, we demonstrate that the functionalization of a hexaphenylbenzene-based molecule with fluorine (F) atoms leads to the formation of molecular self-assemblies with distinct long-range chiral recognition patterns. We employed density functional theory calculations to quantify F-mediated lone pair F⋯π, C–H⋯F, and F⋯F interactions attributed to the distinct enantiospecific molecular self-organizations. Our findings underpin a viable route to fabricate long-range chiral recognition patterns in supramolecular assemblies by engineering the weak non-covalent intermolecular interactions.

Here we report a novel hexaphenylbenzene (HPB)-based material functionalized with six tetraphenylethylene units (BPT) with unique conformation-driven selectivity for gas chromatographic (GC) separations. It is composed of a neat aromatic hydrocarbon with a rigid propeller-like conformation. As a result, the BPT capillary column exhibited high column efficiency of 5340 plates per m and high-resolution capability for aromatic to aliphatic isomers with excellent intra-day and inter-day repeatability and between-column reproducibility. The results demonstrate the unique conformation-driven selectivity of the HPB-based stationary phase, which is rarely reported for chromatography. Moreover, its application in the determination of isomer impurities in commercial products proved its good potential for practical GC analysis. This work presents a new perspective for developing selective stationary phases by engineering their structures.

A supramolecular catalytic ensemble HP-T@Au-Fe3O4 supported by highly branched assemblies of hexaphenylbenzene (HPB) derivatives has been developed. The as-prepared HP-T@Au-Fe3O4 nanohybrid material serves as an efficient catalytic system to prepare biaryl derivatives through the Kumada cross-coupling reaction using aryl chlorides as one of the coupling partners under mild reaction conditions (visible light irradiation, aqueous media, aerial conditions, short reaction time). Through the cooperative effect of Au NPs and Fe3O4 NPs, dual activation of aryl chlorides for the generation of aryl radical intermediates is achieved. On the other hand, oligomeric assemblies contributed significantly to the enhancement of the reaction rate and yield of the product by facilitating the reductive elimination step. Different mechanistic studies confirm the involvement of Au NPs, Fe3O4 NPs and oligomeric assemblies in the synergistic and balanced operation of HP-T@Au-Fe3O4 nanohybrid materials in the efficient completion of the catalytic cycle of the Kumada coupling reaction. Being magnetic, the catalytic ensemble could be recycled for up to five catalytic cycles. The as-prepared supramolecular photocatalytic ensemble also works efficiently in Heck coupling reactions involving aryl chlorides and aryl iodides as the coupling partner.

Although organic light emitting devices (OLEDs) based on thermally activated delayed fluorescence (TADF) have already achieved impressively high external quantum efficiency (ηext) of over 35%, their operation lifetime still needs to be improved for practical applications. In this study, we developed a molecular design for fabricating high triplet energy (ET = 2.7 eV) multifunctional hole-transport layers (HTLs) based on a hexaphenylbenzene skeleton to realize record-breaking efficient and stable TADF OLEDs. By using a dibenzofuran-end-capped HTL named 4DBFHPB, we could successfully develop a highly efficient, low-drive voltage, and stable green TADF OLED exhibiting an ηext of 19.2% and operation lifetime (LT50) of ∼24 000 h at an initial luminance of 1000 cd m−2. The drive voltage at 1000 cd m−2 was recorded to be 4.07 V. We also developed a sky-blue TADF OLED exhibiting an ηext of 21.5% and LT50 of ∼1700 h at an initial luminance of 500 cd m−2. The developed designs demonstrate record-breaking performances among the existing TADF OLEDs.

A pair of novel optically active triptycene-based molecules ((R,R)-1 and (S,S)-1) containing two hexabenzocoronene moieties were synthesized and their optical and chiroptical properties were investigated. Optically active 1 emitted preferred-handed circularly polarized light upon UV irradiation, with the luminescence dissymmetry factors found to be approximately 1.0 × 10-3. Based on a comparative study using the analogous triptycene derivative with two hexaphenylbenzene units (2), which was the key precursor of 1, the ladder-type rigid structure with an asymmetrically bent geometry was important for optically active 1 to exhibit circularly polarized luminescence (CPL). We also showed that rac-1 undergoes conglomerate crystallization, which allowed CPL to be produced by a random selection of crystals prepared from rac-1.

A novel propeller-shaped molecule (HPB-PDI6) with a hexaphenylbenzene (HPB) core and six peripheral PDI units was synthesized via Co2(CO)8-catalyzed cyclotrimerization and used as an acceptor for organic solar cells (OSCs). The intriguing geometry of the HPB core and the spatial repulsion of the PDI rings created a twisted three-dimensional propeller-shaped conformation for HPB-PDI6. The propeller-shaped conformation could prevent the acceptor molecules from forming large aggregates in the active layer. As expected, the PTB7-Th:HPB-PDI6 blend films show a favorable morphology as well as high and balanced charge carrier mobility. Devices based on PTB7-Th:HPB-PDI6 achieved a PCE of 6.63% with a Voc of 0.92 V, a Jsc of 15.11 mA cm−2, and an FF of 48.0%. Our results have demonstrated that the easily prepared propeller-shaped HPB-PDI6 could be a promising acceptor for high efficiency organic solar cells.

Ultrafine hybrid Cu2O–Fe2O3 NPs have been prepared using the supramolecular assemblies of hexaphenylbenzene (HPB) derivative 3 as nanoreactors and stabilizers. The as-prepared hybrid Cu2O–Fe2O3 NPs serve as an efficient and recyclable photocatalytic system for carrying out C–N coupling between aryl halides and various amines (aliphatic, aromatic and N-heterocyclic) at room temperature in mixed aqueous media under visible light irradiation. Amazingly, Cu2O–Fe2O3 NPs also exhibited high efficiency in the reactions involving the synthesis of biologically important N-substituted carbazole derivatives. The work being presented in this article demonstrates the preparation of a ‘dip strip’ coated with the as-prepared catalytic system and utilization of this paper strip as a recyclable and portable heterocatalytic system for carrying out the Ullmann–Goldberg coupling.

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.

The organo-soluble and extremely stable polynorbornene PHNB-HPB with a hexaphenylbenzene (HPB) moiety was prepared by ring-opening metathesis polymerization (ROMP) followed by hydrogenation. The hexa-peri-hexabenzocoronene (HBC)-containing PHNB-HBC, which is insoluble in commercial organic solvents, was prepared by the cyclodehydrogenation of PHNB-HPB. The glass transition temperature of PHNB-HPB was 205 °C. The temperatures required for a 10% weight loss (Td10) for PHNB-HPB and PHNB-HBC were 428 °C and 456 °C under a nitrogen flow, respectively. The PHNB-HBC exhibited an ordered self-assembly in the solid state. The exfoliation of PHNB-HBC aggregates was tested by ultrasonication in various solvents. The PHNB-HBC dispersion solutions showed an intensive emission of the 0–0 transition (465 nm) due to the lower D6h symmetrical structure and alkoxy substituents. Between different solvents, the dispersion in N-cyclohexyl-2-pyrrolidone (CHP) showed the highest individual metric and the strongest 0–0 transition (465 nm), indicating higher dispersibility.

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.

In this study, a new triphenylamine-alt-fluorene conjugated copolymer, HPBPYFL6, with hexaphenylbenzene (HPB) and pyrene as asymmetrical pendant groups was synthesized via Suzuki coupling polymerization. The conjugated polymer had a weight-average molecular weight of 5.8 × 104 g mol−1 with a polydispersity index of 2.5 characterized by gel permeation chromatography (GPC). HPBPYFL6 showed good solubility in common organic solvents such as NMP, THF, toluene and dichloromethane at 25 °C. In addition, HPBPYFL6 possessed a high glass transition temperature of 260 °C and a 10% weight-loss temperature of 503 °C in nitrogen. HPBPYFL6 bearing a pyrene moiety had a solvatochromic fluorescence shift from a green to an orange emission as the polarity of the solvent increased. Cyclic voltammetry of HPBPYFL6 films cast onto indium-tin oxide-coated glass (ITO-glass) exhibited two oxidation redox couples at an E1/2 value of 0.82 and 1.17 V versus Ag/Ag+ in an acetonitrile solution. The HPBPYFL6 film on graphene-coated PET had an E1/2 value of 0.24 and 1.12 V. Conjugated polymer films exhibited reversible electrochromic behaviour with a colour change from pale yellow to deep blue upon electrochemical oxidation and high absorbance in the near-infrared (NIR) region. The switching and bleaching times were 5.16 s and 3.12 s for 1231 nm and were 3.30 s and 3.74 s for 1030 nm of HPBPYFL6 on ITO-glass. The strong NIR electrochromic absorbance of HPBPYFL6 was attributed to intervalence charge transfer by the incorporation of the HPB moiety. This phenomenon was confirmed by chemical oxidation as the oxidant contents increased in the solution state. Furthermore, the electrochromic mechanism was interpreted by DFT calculation and the simulated NIR electrochromic spectra of model compound HPBPYFL are in good agreement with the experimental data.

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.

Toxic volatile organic compounds (VOCs) including benzene and toluene that are emitted from industrial chemical processes and outdoor or indoor chemical applications are harmful to the environment and threaten human health. Porous organic polymers (POPs), which have attracted much interest during the last decade as materials for gas adsorption and separation, have only recently gained attention for the adsorption of VOCs. We synthesised two POPs based on hexaphenylbenzene (HEX-POP-93) and hexabenzocoronene (HBC-POP-98) and studied the adsorption of organic vapours. Interestingly, while both POPs have moderate BET surface areas (687 and 548 m2 g−1 respectively), they both show an excellent affinity for organic vapours over water, with a high benzene adsorption capacity of 99.9 wt% for HEX-POP-93.

A rhodamine appended hexaphenylbenzene based derivative 5 has been designed and synthesized, which displays through bond energy transfer in the presence of picric acid in MeOH and serves as “turn on” sensor for picric acid. Furthermore, derivative 5 exhibits an intense colorimetric response towards picric acid and can selectively detect picric acid with a detection limit of 104.9 pg cm−2.

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.

The synthesis of π-extended [12]cycloparaphenylene (CPP) derivatives from a kinked triangular macrocycle is presented. Depending on the reaction conditions for reductive aromatization, either a hexaphenylbenzene cyclohexamer or its C2-symmetric congener was obtained. Their structures were confirmed by NMR spectroscopy or X-ray crystallographic analysis. With the support of DFT calculations, a mechanistic explanation for the unexpected formation of the oval shaped bis(cyclohexadiene)-bridged C2-symmetric macrocycle is provided. The here employed congested hexaphenylbenzene mode of connectivity in conjunction with a non-strained precursor improves oxidative cyclodehydrogenation toward the formation of ultrashort carbon nanotubes (CNT)s. Thus, this strategy can pave the way for new conceptual approaches of a solution-based bottom-up synthesis of CNTs.

A series of hexaarylbenzenes (1–6) with a variety of different aryl arms (i.e. phenyl, biphenylyl, mono-, bi-, and terthienylyl) around a benzene core, decorated with flexible dodecyl chains on the terminal positions, were synthesized. Their mesomorphic behaviors were studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XD) techniques. Compounds 1–3, which have a hexaphenylbenzene core, form columnar mesophases. In particular 3, in which the core is composed of hexaphenylbenzene surrounded by thiophene rings, shows a stable columnar mesophase (d-Dh) over a large temperature range compared to its phenyl analogs, hexakis(4-dodecylphenyl-4-yl)benzene (1) and hexakis(4′-dodecylbiphenylyl)benzene (2). Compounds 4–6, hexa(oligo-α-thienylyl)benzenes, tend to form less ordered mesophases after annealing for a longer time. Compounds 4 and 5 form discotic nematic mesophases (Nd) at temperatures well below the decomposition temperature.

Hexaphenylbenzene based tritopic carboxylate ligands H3L1 (1,3,5-tris(4-carboxyphenyl)-2,4,6-tris(4-tert-butylphenyl)benzene) and H3L2 (1,3,5-tris(4-carboxyphenyl)-2,4,6-triphenylbenzene) were applied to synthesize six coordination polymers (CPs) {[Zn4(L1)2(μ2-OH)2(DMA)4(H2O)]·(C2H6O)2(H2O)}n (1), {[Cd3(L1)2(μ2-H2O)2(H2O)4(DMF)2(C2H6O)]·(DMF)(H2O)(C2H6O)2}n (2), {[Cd(L1)(C2H6O)]·(H3O+)(DMF)(C2H6O)}n (3), {[Co3(L1)2(μ2-H2O)(H2O)6(DMF)2(C2H6O)]·(DMF)3}n (4), {[Mn3(L1)2(H2O)5(DMF)4(C2H6O)]·(C2H6O)}n (5), and {[Zn2(L2)Cl(H2O)(DMA)]·(DMA)2(H2O)}n (6) (DMF = N,N-dimethylformamide, DMA = N,N-dimethylacetamide). The CPs were characterized by single crystal X-ray diffraction, infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). 1 and 2 exhibit two-dimensional (2D) honeycomb bilayer structures based on tetranuclear zinc or trinuclear cadmium clusters. 3 is PH-induced supramolecular isomer with 2, featuring 2D corrugated honeycomb structure. In 4 and 5, only two carboxylate groups coordinate with trinuclear metal clusters to form 1D coordination chains. The chains are further connected through hydrogen bonds between the left carboxylate groups and coordination water molecules to form honeycomb bilayer sheets. 6 exhibits 2D planar honeycomb structure based on Zn2(COO)3 clusters. The different topological networks 1 and 6 are constructed from structurally similar ligands H3L1 and H3L2, showing that structural diversity could be realized by adjusting substituent groups on organic ligands. The photoluminescent behaviours of compounds 1, 2, and 6 and magnetic properties of 4 and 5 were also investigated.

Hexaphenylbenzene (HPB) derivatives 5 and 7 having rhodamine B moieties have been designed and synthesized, and have been shown to display solvent dependent. Fluorescence resonance energy transfer (FRET) and through bond energy transfer (TBET) in the presence of Hg(2+) ions among the various cations (Cu(2+), Pb(2+), Zn(2+), Ni(2+), Cd(2+), Ag(+), Ba(2+), Mg(2+), K(+), Na(+), and Li(+)) have been tested. Derivative 5 displays quite high through bond energy transfer efficiency in the presence of Hg(2+) ions in methanol whereas derivative 7 exhibits better FRET efficiency in the presence of Hg(2+) ions in THF and CH(3)CN than derivative 5.

A novel organic microporous polymer (HTP) has been synthesized from a hexaphenylbenzene based triptycene monomer by Ni(0)-catalyzed Ullmann cross-coupling reaction, which displays a BET surface area of 1151 m2 g−1 and reversibly 12.5 wt% CO2 at 1.0 bar/273 K.

A photo/redoxactive hexa-peri-hexabenzocoronene-porphyrin conjugate with a direct connection between the two chromophores was synthesised using a formylated hexaphenylbenzene precursor.

A series of blue-emitting triarylamines containing pyrene and hexaphenylbenzene dendrons were successfully synthesized by employing the Diels–Alder and palladium catalyzed C–N coupling reactions. They display high glass transition temperatures (>140 °C) in differential scanning calorimetry and facile reversible oxidation couple in cyclic voltammetry. They are also thermally stable exhibiting decomposition temperature above 385 °C. Efficient blue-emitting electroluminescent devices were fabricated using these novel amines as the hole transporting layer and 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) as the electron transporting layer. Colour mixing or green emission was observed when tris(8-hydroxyquinoline)aluminium (Alq3) was used as the electron transporting layer. However insertion of a thin layer of TPBI or 1,3,5-tris(4-tert-butylphenyl-1,3,4-oxadiazolyl)benzene (TPOB) in between the HTL and Alq3 layers led to pure blue emission owing to the confinement of recombination inside the HTL layer containing the compounds.

The bimetal compound [RhW(µ-CR)(CO)3(η-C5H5)(η-C9H7)](R = C6H4Me-4, C9H7= indenyl) reacts with the alkynes R1CCR2(R1= R2= Ph or Me; R1= Ph, R2= H or Me) in toluene at ca. 50–80 °C to give the bridged complexes [RhW{µ-C(R)C(R1)C(R2)}(CO)2(η-C5H5)(η-C9H7)]. The molecular structure of the species obtained from PhCCPh was established by a single-crystal X-ray diffraction study. A Rh–W bond [2.754(1)A] is bridged by a three-carbon chain [mean C–C 1.439(8)A]. Whereas all the atoms of the chain are bound to the rhodium [2.105(6), 2.135(6), and 2.103(5)A], only the two end carbons are attached to the tungsten [2.175(5) and 2.196(6)A]. The tungsten atom carries two essentially orthogonal terminal carbonyl groups, as well as the cyclopentadienyl ring. The indenyl group is asymmetrically attached to the rhodium atom, with three short Rh–C [2.185(7), 2.198(7), and 2.204(7)A] and two long Rh–C [2.334(7) and 2.330(7)A] separations to the C5 ring, implying slippage towards an η3-bonding mode. Formation of [RhW{µ-C(R)C(Ph)C(Ph)}(CO)2(η-C5H5)(η-C5Me5)] from [RhW(µ-CR)(CO)3(η-C5H5)(η-C5Me5)] and PhCCPh requires forcing conditions (100 °C, 5 d in toluene), and side-reactions occur to yield hexaphenylbenzene, [Rh(CO)2(η-C5Me5)], and the tetraphenylcyclopentadienone complex [Rh(µ-C4Ph4CO)(η-C5Me5)]. The reaction between [RhW(µ-CR)(CO)3(η-C5H5)(η-C9H7)] and [W(CR)(CO)2(η-C5H5)] has also been investigated. With heptane as solvent, the products are the trimetal complex [Rh2W(µ3-CR)(µ-CO)(CO)2(η-C5H5)(η-C9H7)2], the alkyne-bridged complex [W2(µ-RC2R)(CO)4(η-C5H5)2], and a compound formulated as [W2{µ-C(R)C(O)C(R)}(CO)4(η-C5H5)2]. Spectroscopic data (i.r., 1H and 13C-{1H} n.m.r.) for the new compounds are reported and discussed.