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The title compound, [Re(C17H22N3O2S)(CO)3] is a net neutral fac-Re(I)(CO)3 complex of the 4-methylbiphenyl sulfonamide derivatized diethylenetriamine ligand. The NNN-donor monoanionic ligand coordinates with the Re core in tridentate fashion, establishing an inner coordination sphere resulting in a net neutral complex. The complex possesses pseudo-octahedral geometry where one face of the octahedron is occupied by three carbonyl ligands and the other faces are occupied by one sp2 nitrogen atom of the sulfonamide group and two sp3 nitrogen atoms of the dien backbone. The Re—Nsp2 bond distance, 2.173 (4) Å, is shorter than the Re—Nsp3 bond distances, 2.217 (5) and 2.228 (6) Å, and is similar to the range reported for typical Re—Nsp2 bond lengths (2.14 to 2.18 Å).

In our continuation of exploring antidiabetic agents from Garcinia species, we found that the methanolic extract of G. macrantha A.C.Sm. exhibited considerable α-glucosidase inhibition of 58.20 ± 0.37% in sucrose substrate and 39.86 ± 2.07% in maltose substrate at 100 μg/mL. Phytochemical investigation on the extract revealed the presence of a new biphenyl, macrabiphenyl A, which was successfully elucidated by means of spectroscopic methods (HRESIMS and 1D and 2D NMR). The α-glucosidase inhibitory evaluation indicated that the new compound was weakly active against the enzyme. [ABSTRACT FROM AUTHOR]

With the popularization of 5G technology and artificial intelligence, thermally conductive epoxies with self‐healing ability will be widely used in flexible electronic materials. Although many compounds containing both performances have been synthesized, there is little systematic theory to explain the coordination mechanism. In this paper, alkyl chains of different lengths were introduced to epoxies to discuss the thermally conductive, the self‐healing performance, and the synergistic effect. A series of electronic‐grade biphenyl epoxies (4,4′‐bis(oxiran‐2‐ylmethoxy)‐1,1′‐biphenyl (1), 4,4′‐bis(2‐(oxiran‐2‐yl)ethoxy)‐1,1′‐biphenyl (2), 4,4′‐bis(3‐(oxiran‐2‐yl)propoxy)‐1,1′‐biphenyl (3), and 4,4′‐bis(4‐(oxiran‐2‐yl)butoxy)‐1,1′‐biphenyl (4) were synthesized and characterized. Furthermore, they were cured with decanedioic acid to produce polymers. Results showed that alkyl chains can both affect the two properties, and the epoxies suitable for specific application scenarios can be prepared by adjusting the length of alkyl chains. In terms of thermal conductivity, compound 1 was a most promising material. However, compound 4 was expected to be utilized in flexible electronic devices because of its acceptable thermal conductivity, self‐healing ability, transparency, and flexibility. [ABSTRACT FROM AUTHOR]

The biosynthesis of fatty acids is an important metabolic pathway in bacterial organisms. Previous studies have highlighted the synthesis of antimicrobial compounds anchored in the benzodioxepin scaffold and known for their pronounced antibacterial properties. Based on this fundamental knowledge, a series of eight innovative benzodioxepin-biphenyl amide derivatives were carefully designed and synthesized in the current research work. This was achieved through a sophisticated optimization of the synthetic methods. The scope of this study extends to a rigorous evaluation of the antibacterial properties and biocompatibility of the above-mentioned new derivatives. In particular, compound E4 proved to be an extremely effective antimicrobial agent. In addition to a detailed elucidation of the crystalline architecture of compound E4, a thorough docking study was also carried out to investigate the interactions with the enzyme FabH. [ABSTRACT FROM AUTHOR]

Herbicides are useful tools for managing weeds and promoting food production and sustainable agriculture. In this study, we report on the development of a novel class of lipophilic pyrimidine-biphenyl (PMB) herbicides. Firstly, three PMBs, Ia, IIa, and IIIa, were rationally designed via a scaffold hopping strategy and were determined to inhibit acetohydroxyacid synthase (AHAS). Computational simulation was carried out to investigate the molecular basis for the efficiency of PMBs against AHAS. With a rational binding mode, and the highest in vitro as well as in vivo potency, Ia was identified as a preferable hit. Furthermore, these integrated analyses guided the design of eighteen new PMBs, which were synthesized via a one-step Suzuki–Miyaura cross-coupling reaction. These new PMBs, Iba-ic, were more effective in post-emergence control of grass weeds compared with Ia. Interestingly, six of the PMBs displayed 98–100% inhibition in the control of grass weeds at 750 g ai/ha. Remarkably, Ica exhibited ≥ 80% control against grass weeds at 187.5 g ai/ha. Overall, our comprehensive and systematic investigation revealed that a structurally distinct class of lipophilic PMB herbicides, which pair excellent herbicidal activities with new interactions with AHAS, represent a noteworthy development in the pursuit of sustainable weed control solutions. [ABSTRACT FROM AUTHOR]

The synthesis of 1-(4(tert-butyl)-4-methoxy-[1,1-biphenyl]-4-yl) ethenone (4TBMBE) has been realized in excellent yield by using 4-tert-butyl phenylboronic acid and 1-bromonitrobenzene as the reactants. The single crystals were obtained by solvent-loss technique and its characterization was carried out using the spectral and X-ray diffraction methods. The molecule crystallizes in the monoclinic crystal system with space group (P21/c). There exists one C–H...O intramolecular and an intermolecular C–H···π interaction, besides one π···π (Cg···Cg) interaction responsible for stabilizing the unit cell molecular packing. The density functional theory has been employed to optimize the structure and to carry out the HOMO/LUMO analysis, computation of reactivity parameters, molecular electrostatic potential map and Mulliken population analysis. The Hirshfeld surface analysis probes the existence of various interactions in the crystal structure. Crystal voids analysis confirmed the absence of any significant cavity within the crystal packing. The relative contribution for each contact has been analyzed using the 2D fingerprint plots and their favourability has been validated by the enrichment ratio. The 3D topology of molecular packing has been visualized using energy framework analysis and the nature of molecular interactions existing within the structure has been ascertained using NCI-RDG analysis. The molecular docking investigations have been performed to study the anti-inflammatory action of 4TBMBE against the p38 MAP kinase inhibitor. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium-ion batteries (LIBs) and electrical double-layer capacitors (EDLCs) are widely used in commercial energy storage systems, but each has inherent limitations. To overcome these limitations, the lithium-ion capacitor (LIC) has emerged as a hybrid energy storage device, combining the benefits of LIBs and EDLCs. However, the introduction of active lithium into LICs poses challenges due to lithium's reactivity and instability. In this study, we propose a dual wet chemical prelithiation strategy to enhance LIC performance. By wet chemically prelithiating both the activated carbon cathodes and hard carbon anodes, significant improvements are achieved compared to traditional prelithiation methods. The dual prelithiation approach outperforms electrochemical prelithiation in terms of energy storage performance, cycle life, and process simplification. LICs with dual wet chemically prelithiated electrodes demonstrate the highest energy density and retain a substantial portion of reversible capacity even at high discharge rates. The strategy exhibits fast kinetics and wide operational stability. In contrast, LICs with metallic lithium anodes or electrochemically prelithiated hard carbon anodes exhibit inferior performance and limited cycle life. The dual wet chemical prelithiation strategy represents a breakthrough in LIC technology, offering superior performance, cycle stability, and scalability. It holds promise for alkali-ion energy storage systems and drives advancements in electrochemical energy storage technology. [ABSTRACT FROM AUTHOR]

A biphenyl derivative in which two benzene rings are strapped with two chains is prepared. The synthesized product shows molecular asymmetry, which was confirmed by HPLC analysis with chiral column and named as winding vine‐shaped biphenyl. The synthesis of such vine shaped molecule was performed by ring‐closing metathesis or alternatively by annulation with nosylated ethylenediamine. The structure of the obtained product was confirmed by X‐ray crystallographic analysis. The absolute configuration of the molecular asymmetry was assigned after leading to the corresponding camphor sulfonamide through denosylation and re‐amidation process. [ABSTRACT FROM AUTHOR]

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A series of calamitic biphenyl ester-aromatic imine derived from the reaction of 4-formylphenyl-4'-(alkyloxy)-[1,1'-biphenyl]-4-carboxylate and p-anisidine have been successfully synthesised and characterised. The general molecular structures of ultimate compounds show the central fragment made up by a hybrid core of biphenyl ester-aromatic imine in which the terminal alkoxy chains, CnH2n + 1 in which n = 7–12 were connected to biphenyl while the other end consists of methoxy moiety attached to a phenyl ring. All the target compounds under polarised lights exhibit enantiotropic nematic phase of which the temperature range was further supported by DSC analysis. It can be summarised that the lengthening of terminal alkoxy chains has contributed to the lowering of melting and clearing temperatures as well as the thermal stability of nematic phase. A dedicated magnetic characterisation analysis disclosed that apart from a dominant diamagnetic character these compounds possess a noticeable magnetic interaction despite knowing that the compounds belong to the non-metal and non-radical containing species. [ABSTRACT FROM AUTHOR]

To meet the demands of high-density and miniaturized integrated circuits, electronic packaging materials need to have excellent properties. One approach to enhance the performance is to design novel structures. In this study, two novolac oligomers containing naphthalene Naphthalene novolac oligomer (NPF) and biphenyl Biphenyl novolac oligomer (LPF) were synthesized and then reacted with epichlorohydrin to synthesize novel novolac epoxy resins containing polycyclic aromatic hydrocarbons (NPF-EP and LPF-EP). Their chemical structures were characterized by Fourier transform infrared and ¹H nuclear magnetic resonance spectra. Tetrahydromethyl-1,3-isobenzofurandione (MeTHPA) was used as curing agent to prepare cured NPF-EP/MeTHPA and LPF-EP/MeTHPA thermosets. Both NPF-EP/ MeTHPA and LPF-EP/MeTHPA exhibited better thermal and mechanical properties compared with novolac epoxy resin (PF-EP/MeTHPA). In particular, NPF-EP/MeTHPA presented the highest glass transition temperature of 193°C and LPF-EP/MeTHPA had excellent mechanical properties, with tensile and flexural strengths of 94 and 151 MPa, respectively. Additionally, the cured NPF-EP/ MeTHPA and LPF-EP/MeTHPA also exhibit a lower dielectric constant and dielectric loss, and low coefficient of thermal expansion compared with cured PF-EP/MeTHPA. This investigation provides valuable insights for the manufacturing of high-performance novolac epoxy resins for application in electronic packaging materials. [ABSTRACT FROM AUTHOR]

Some cinnamic acid and biphenyl core-derived calamitic molecules were synthesized and characterized for mesomorphic properties. Newly synthesized compounds showed well-defined schlieren textures and mosaic textures for the nematic phase and a relatively well-organized smectic A phase with focal conic textures. The chemical structures were confirmed by FT-IR, 1H-NMR, 13C-NMR and elemental analysis. The thermotropic behavior, optical textures and thermal stability have been investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), X-ray diffraction (SAXS) and thermal gravimetric analysis (TGA) respectively. [ABSTRACT FROM AUTHOR]

Abstract Background Telmisartan (TLT) is a prototypic angiotensin receptor blocker largely used to treat hypertension worldwide. In addition to its cardioprotective effects, TLT presents pleiotropic activities and notably displays noticeable anti-inflammatory and antitumor effects. The repression of the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint may be implicated antitumor action of TLT, as it is the case with many other compounds equipped with a biphenyl moiety. We have used molecular modeling to compare the interaction of TLT and derivatives with the PD-L1 dimer protein. Results Two molecules, TLT-dimer and TLT-acylglucuronide, were found to form more stable complexes with PD-L1 than TLT itself. In parallel, the docking analysis performed with a series of 12 sartans led to the identification of Olmesartan as a potential PD-L1 binder. The stacked biphenyl unit of Olmesartan positions the molecule along the groove delimited by the two protein monomers. The flanking tetrazole and imidazole moieties, on each side of the biphenyl unit of Olmesartan, contribute favorably to the protein interaction via specific hydrogen bonding interactions. Conclusions The computational analysis suggests a possible binding of Olmesartan to PD-L1 dimer and thus offers novel perspectives for the design of small molecules capable of interrupting the PD-1/PD-L1 immune checkpoint. Experimental studies are warranted to validate the hypothesis. Graphical abstract

Context: The present study accounts for the quantum chemical and nonlinear optical properties of the combination of para-aminobenzoic acid and 7-diethylamino 4-methyl coumarin. Three different complexes were designed, surface interaction (adsorption) and two by connecting both molecules with π-bridge benzene and biphenyl. The amino and carboxyl groups were observed to behave as strong donor and acceptor sites in all the complexes. The band gap of the adsorbed complex was found more suitable. The absorption wavelength and intensity both were seen to increase with the increase in the number of benzene rings in the π-bridge. The values of first- and second-order hyperpolarizability suggest the improved nonlinear optical responses of the introduced complexes. Additionally, the negative value of second-order hyperpolarizability suggests the possibility of the occurrence of reverse saturable absorption in these combinations. The reported work gives theoretical insights into the nonlinear optical properties of the combination of para-aminobenzoic acid and 7-diethylamino 4-methyl coumarin. Methods: The molecular modeling and the quantum chemical studies were performed with Gaussian software packages. The standard B3LYP-6-311++G(d,p) basis functionals were used for energy minimization and other spectral calculations. All the surface analyses reported here are obtained by employing Multiwfn software. The chemical reactivity was established by the global reactivity descriptors. The intramolecular interactions and charge localization were stated using inter-fragment charge transfer analysis. [ABSTRACT FROM AUTHOR]

Comparative spectroscopic investigation of Biphenyl-4-carboxylic acid (BCA), 4-Acetylbiphenyl (ACB) and 2,4-difluorobiphenyl (DFB) are obtained by using Density Functional Theory (DFT) with B3LYP functional at 6-311++G(d, p) basis set. The vibrational assignments have been proposed with aid of the results of Normal Coordinate Analysis (NCA). The effects of carboxyl, acetyl and fluoro substituents on the vibrational frequencies of biphenyl have been investigated and compared. The molecular stability and bond strength was investigated by applying the Natural Bond Orbital (NBO) analysis. The other molecular properties like Mulliken charge analysis, HOMO-LUMO analysis and Molecular Electrostatic Potential (MESP) of the title compounds have been reported. In vitro analysis have been performed with two fungal pathogens Aspergillus niger and Candida albicans using well diffusion method. BCA compound exhibited excellent activity against the Aspergillus niger with zone of inhibition values in the range of 22 and 25 mm in 40 and 80 µl with 10 mg/ml. Molecular docking studies of the most active compound are carried out, and results showed reasonable binding modes in the fungicide active site of phytase protein Fophys and Succinate dehydrogenase (SDH) proteins. A preliminary Structure-Activity Relationship study of the biphenyl derivatives has led to the recognition of some important structural requirements for antifungal activity. Furthermore the fungicide-likeness analysis of BCA, DFB and ACB compounds have been developed to predict its fungicide activity by using fungiPAD webtool. [ABSTRACT FROM AUTHOR]

Background: Telmisartan (TLT) is a prototypic angiotensin receptor blocker largely used to treat hypertension worldwide. In addition to its cardioprotective effects, TLT presents pleiotropic activities and notably displays noticeable anti-inflammatory and antitumor effects. The repression of the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint may be implicated antitumor action of TLT, as it is the case with many other compounds equipped with a biphenyl moiety. We have used molecular modeling to compare the interaction of TLT and derivatives with the PD-L1 dimer protein. Results: Two molecules, TLT-dimer and TLT-acylglucuronide, were found to form more stable complexes with PD-L1 than TLT itself. In parallel, the docking analysis performed with a series of 12 sartans led to the identification of Olmesartan as a potential PD-L1 binder. The stacked biphenyl unit of Olmesartan positions the molecule along the groove delimited by the two protein monomers. The flanking tetrazole and imidazole moieties, on each side of the biphenyl unit of Olmesartan, contribute favorably to the protein interaction via specific hydrogen bonding interactions. Conclusions: The computational analysis suggests a possible binding of Olmesartan to PD-L1 dimer and thus offers novel perspectives for the design of small molecules capable of interrupting the PD-1/PD-L1 immune checkpoint. Experimental studies are warranted to validate the hypothesis. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of a novel amino triflamide catalyst and its application in enamine catalysis. The catalyst is derived from commercially available 1-nitropyrene and has a unique reactivity and selectivity. The synthesis of the catalyst involves several steps, but it offers a more efficient alternative to previously developed catalysts. The article also presents the results of several asymmetric reactions using the newly synthesized catalyst, demonstrating its utility in synthetic organic chemistry. [Extracted from the article]

In the current study, two new unsymmetrical liquid crystalline homologous series of dimers with a rigid biphenyl core were synthesised using an ether-linking group. Several spectroscopic methods, including FT-IR, 1H-NMR, 13C-NMR, elemental analysis and mass spectrometry, were used to describe the synthesized dimers. Differential scanning calorimetry (DSC) and polarised optical microscopy (POM) were used to assess their mesomorphic properties. The results showed that the number of methylene spacers significantly affected the thermal properties of the synthesized dimers. To ascertain photophysical behaviour, UV–Visible spectroscopy was employed. Nematic-type mesophase patterns with good mesophase range and thermal stability were seen in both series. Dimers with flexible spacers (n = 2, 4, 6) had the best liquid crystalline nature out of all the dimers. The relationships between structure and its mesogenic property, the effects of various flexible spacers, the mesophase ranges, and the photo-isomerization of liquid crystalline dimers were all investigated. DFT Studies were carried out to gain a better understanding of structural features. [ABSTRACT FROM AUTHOR]

In natural ecosystems, parasites and their hosts are subject to xenobiotics, which overall weaken either a host or its parasites. There has been no laboratory study of this process on the example of cockroaches and their parasites. In accurately controlled conditions, we examined the influence of a food supplement – biphenyl – on cockroaches and their three parasites. In the conditions of our experiment, Blaberus cranifer (Blattodea, Blaberidae) cockroaches significantly reduced the rates of anabolism even while consuming the lowest biphenyl concentration in their diet. While the control group was observed to have a 59.4 mg/day increase in body mass, the mass of the cockroaches given biphenyl in the dose of 0.5% of diet mass decreased by 3.4 mg/day on average. Subject to high dosages of biphenyl (0.5–16.0% of fodder mass), body mass of the cockroaches decreased on average by 1.1–9.4 mg/day. The insects consumed their diet at the same rate, no matter the biphenyl concentration given. The number of gregarines Blabericola cubensis (Eugregarinorida, Blabericolidae) and Protomagalhaensia granulosae did not change even at the highest concentration (16.0% of fodder mass) added to the B. craniifer cockroaches’ diet. We observed no significant changes in the amount of larvae of the Cranifera cranifera (Oxyurida, Thelastomatidae) nematodes, while the adult nematodes tended to decline in number when subject to increased concentration of the food supplement in the cockroaches’ food. The number of P. granulosae gregarines did not significantly increase with body-mass gains of their hosts – cockroaches, that is despite increase in volume of their living environment (the midgut of cockroaches) and extension of the period during which the cockroaches consumed gregarine oocysts from the environment with food. Similarly, the number of B. cubensis gregarines also did not significantly change with increased food consumption by the cockroaches. However, we observed a tendency towards greater numbers of this gregarine in the cockroach larvae that were losing mass during the experiment. The greatest mass loss during the experiment was observed in the cockroaches that consumed biphenyl in the diet and had the largest number of C. cranifera nematodes in the hindgut. We observed no significant negative correlation between the numbers of B. cubensis and P. granulosae gregarines. A cockroach that was found to have 70 specimens of B. cubensis in the midgut, had no P. granulosae gregarines. In contrast, when the intestines of a cockroach contained over 10–15 specimens of P. granulosae, some B. cubensis were always present. The number of C. cranifera nematodes in the cockroaches’ hindgut did not depend on the number of B. cubensis or P. granulosae gregarines in their hosts’ midgut. Perhaps, this was related to absence of competition for the intestinal section among them. The regularities we found are different from what we expected to see in the parasitic system prior to the experiment. Gregarines did not compete with nematodes. Neither of them died from biphenyl, though the cockroaches ceased to normally gain weigh when eating biphenyl. That is, the host suffered from biphenyl more than the parasites, even when consuming the lowest concentration of the xenobiotic we tested.

Abstract The emergence of pest resistance of Spodoptera littoralis (order; Lepidoptera, family; Noctuidae) towards the large scale of different classes of insecticides necessitates the development of some new poly-functionalized biphenyl and azabiphenyl with highly anticipated insecticidal bioresponse. Four new biphenyl carboxamidines 4a–d and four aza-analogue picolinamidine derivatives 8a–d were designed and prepared via the treatment of their corresponding carbonitriles with lithium-bis trimethylsilylamide [LiN(TMS)2], followed by hydrolysis with hydrogen chloride. Furthermore, these compounds were elucidated by spectral data, and their toxicity and insecticidal activity were screened against Spodoptera littoralis. Whereby, toxicological and biochemical aspects of the inventively synthesized biphenyl and azabiphenyl derivatives against the cotton leafworm, Spodoptera littoralis were inspected. As regards the indomitable LC50 and LC90 values, biphenyl and aza-analogues 8d, 8a, 4b, and 8b, revealed the furthermost forceful toxic effects with LC50 values of 113.860, 146.265, 216.624, and 289.879 ppm, respectively. Whereby, their LC90 values are 1235.108, 1679.044, 2656.296, and 3381.256 ppm, respectively, and toxicity index being 22.31%, 17.36%, 11.72%, and 8.76%, respectively, comparing with the already recommended, methomyl insecticide, lannate 90% SP (LC50, 25.396 and LC90, 57.860 and toxicity index, 100%). Additionally, electrochemical parameters via DFT studies were carried out for demonstrating and elucidation of structure–activity relationship (SAR) according to highly motived compounds, descriptors, and the in vivo insecticidal activities. Graphical Abstract

The scaffold-based drug design has been widely used in new drug discovery. Biphenyl and its analog scaffold are found in many drugs and naturally occurring compounds. To date an array of synthetic methodologies have been introduced to access biphenyl analogs with good yield. Biphenyl scaffolds have shown wide range of biological activities such as anti-inflammatory, antihypertensive, treatment of CNS disorders, anti-cancer, anti-HIV, etc. Also, the importance of biphenyl atropisomers is discussed. This review aims to highlight the evidence of biphenyl motif as a privileged scaffold in various natural products and anticancer agents.

The investigation of chemical constituents from the rhizomes of Ruscus aculeatus resulted in the isolation of two new biphenyl derivatives, aculebiphenyls A and B (1-2), together with two known analogs (3-4). Their chemical structures were elucidated based on extensive spectroscopic interpretation and HR-ESI-MS analysis. Compounds 3-4 were isolated from the Ruscus genus for the first time. The isolated compounds were tested for anti-inflammatory activities and antibacterial activities. Compound 1 exhibited significant inhibitory effects on LPS-induced NO production and COX-2 with IC50 values of 10.8 µM and 0.4 µM. Compound 1 also significantly down-regulated the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α. Compound 1 showed moderate antibacterial activities. [ABSTRACT FROM AUTHOR]

Structurally simple two rod-like mesogens with a three-ring core consisting of biphenyl and phenyl rings are synthesised to investigate the mesophase properties, molecular organisation and the orientational order parameter. In mesogen-1, a dodecyloxy terminal chain is present on the biphenyl ring while the phenyl ring is free from substituent. For mesogen-2, in addition to the dodecyloxy chain, the butyl chain is placed on the phenyl ring. The Hot-stage optical polarising microscopy (HOPM) and differential scanning calorimetry (DSC) measurements show smectic A (SmA), smectic B (SmB), and crystal E (CryE) phases for mesogen-1 and SmA, smectic C (SmC) and smectic F (SmF) phases for mesogen-2. The presence of smectic mesophases is established by X-ray Diffraction (XRD). 1D and 2D 13C solid-state NMR experiments are performed in smectic mesophases to find the orientational order parameters of the phenyl rings of the core. The main order parameter (Szz) of the mesogens in the SmB and SmF phase is in the range of 0.87–0.93. The excellent spectral resolution noticed in 13C NMR spectra in the SmB mesophase (mesogen-1) indicates that the internal rotations of the molecules along the long axis are primarily unhindered. [ABSTRACT FROM AUTHOR]

Soai's asymmetric autocatalysis represents a highly remarkable example for spontaneous symmetry breaking and enantioselective amplification in the enantioselective alkylation of pyrimidine‐5‐carbaldehydes to the corresponding chiral pyrimidine alcohols. Recently, zinc hemiacetalate complexes, formed from pyrimidine‐5‐carbaldehydes and the chiral product alcohol, were identified by in situ high‐resolution mass spectrometric measurements as highly active transient asymmetric catalysts in this autocatalytic transformation. To study the formation of such hemiacetals and their stereodynamic properties, we focused on the synthesis of coumarin homolog biaryl systems with carbaldehyde and alcohol substituents. Such systems are able to form hemiacetals by intramolecular cyclization. An interesting feature of the substituted biaryl backbone is that tropos and atropos systems can be obtained, enabling or disabling the intramolecular cyclization to hemiacetals. Biaryl structures with various functional groups were synthesized, and the equilibrium and stereodynamics between the closed and open structures were investigated by dynamic enantioselective HPLC (DHPLC). The enantiomerization barriers ΔGǂ and activation parameters ΔHǂ and ΔSǂ were determined from temperature dependent kinetic measurements. [ABSTRACT FROM AUTHOR]

Herbicides are useful tools for managing weeds and promoting food production and sustainable agriculture. In this study, we report on the development of a novel class of lipophilic pyrimidine-biphenyl (PMB) herbicides. Firstly, three PMBs, Ia, IIa, and IIIa, were rationally designed via a scaffold hopping strategy and were determined to inhibit acetohydroxyacid synthase (AHAS). Computational simulation was carried out to investigate the molecular basis for the efficiency of PMBs against AHAS. With a rational binding mode, and the highest in vitro as well as in vivo potency, Ia was identified as a preferable hit. Furthermore, these integrated analyses guided the design of eighteen new PMBs, which were synthesized via a one-step Suzuki–Miyaura cross-coupling reaction. These new PMBs, Iba-ic, were more effective in post-emergence control of grass weeds compared with Ia. Interestingly, six of the PMBs displayed 98–100% inhibition in the control of grass weeds at 750 g ai/ha. Remarkably, Ica exhibited ≥ 80% control against grass weeds at 187.5 g ai/ha. Overall, our comprehensive and systematic investigation revealed that a structurally distinct class of lipophilic PMB herbicides, which pair excellent herbicidal activities with new interactions with AHAS, represent a noteworthy development in the pursuit of sustainable weed control solutions.

The goal of this paper is to study the catalytic activity of clay-based materials doped by silver, copper, and gold nanoparticles in the Suzuki–Miyaura coupling reaction. The catalysts are prepared by homogeneous deposition precipitation at 2 wt% of metal. The properties of the catalysts were obtained using these methods: SEM (scanning electron microscopy), high-angle annular dark field, EDS (energy dispersive spectroscopy), DRS/UV–Vis (diffuse reflectance spectroscopy, UV–Vis), XRD (x-ray diffraction), ICP (elementary analysis), and adsorption–desorption of N2 and infrared spectroscopy. The results showed an almost total homogeneous deposition of the metallic nanoparticles on the clay surface. All the catalysts were used in the synthesis of biphenyls using the Suzuki–Miyaura reaction with phenylboronic acid and different aryl halides under classical heating or under visible irradiation. The results have shown the obtaining of interesting coupling rates exceeding 5.44 mol/h/g which depend on the catalyst nature, the aryl halide, and the mode of the activation of the reaction. The different reaction conditions have been optimized. [ABSTRACT FROM AUTHOR]

Diethylenetriamine (dienH) is one of the most biologically compatible chelate frameworks. Its hydrophilic amine moiety was functionalized via N-sulfonylation with sulfonyl chloride to produce two novel ligands; N(SO2)(bzd)dienH (L1) and N(SO2)(4-Mebip)dienH (L2) and two reported ligands; N(SO2)(1-nap)dienH (L3) and N(SO2)(2-nap)dienH (L4). Treatment of cis-Pt(DMSO)2Cl2with L1, L2, L3 and L4 afforded four novel neutral complexes [Pt(N(SO2)(bzd)dienH)Cl2] (C1), [Pt(N(SO2)(4-Mebip)dienH)Cl2] (C2), [Pt(N(SO2)(1-nap)dienH)Cl2] (C3) and [Pt(N(SO2)(2-nap)dienH)Cl2] (C4) respectively. All synthesized compounds were characterized by 1H NMR, UV-Vis, FTIR and fluorescence spectroscopy. Aliphatic diethylenetriamine protons of the ligands appeared in the 3.00 -2.30 ppm region in 1H NMR spectra recorded in DMSO-d6. Upon complexation, the appearance of two broad NH peaks between 5.00 -7.00 ppm region and another broad peak between 7.00-8.00 ppm confirmed the bidentate denticity of the ligands vs tridentate. The formation of metal complexes was further supported by FTIR spectra in which the S-N stretching band for the metal complexes appears at lower wavenumbers compared to that of the corresponding free ligands. Emission spectra were recorded in methanol and intense fluorescence properties were observed in the 331-364 nm range for the ligands, whereas the corresponding Pt complexes showed quenched fluorescence. In vitro cytotoxic effects were investigated using sulforhodamine B assay, where L2 (< 10 µg/mL) demonstrated increased levels of cytotoxicity followed by C2 (< 25 µg/mL) and C4 (< 50 µg/mL) to non-small cell lung cancer cells in dose and timedependent manner, with less or no cytotoxic effects to normal lung cells tested. Among the compounds tested, C1 and C3 displayed comparatively lower but more potent cytotoxic effects on lung cancer cells. Notably, these compounds did not exhibit any toxicity towards normal cells. Thus, they hold promise as lead compounds for the development of chemotherapeutic agents targeting lung cancer. [ABSTRACT FROM AUTHOR]

Two trans-cyanostilbene derivatives were prepared, and their oxidative dimerizations promoted by horseradish peroxidase-H2O2 were investigated. An M5–M5-coupled biphenyl-type dimer was first synthesized from the biomimetic oxidative coupling reaction of 8-cyano-resveratrol. A novel M5–MO-4-coupled diarylether-type dimer was obtained through the oxidation of 3,5-dibromo-8-cyano-resveratrol and the following debromination reaction. The cyano group at the C-8 of two cyano-stilbenes had obvious influences on the regioselectivity of their coupling reactions. [ABSTRACT FROM AUTHOR]

A simple and efficient nitrile-directed meta-C-H olefination, acetoxylation, and iodination of biaryl compounds is reported. Compared to the previous approach of installing a complex U-shaped template to achieve a molecular U-turn and assemble the large-sized cyclophane transition state for the remote C-H activation, a synthetically useful phenyl nitrile functional group could also direct remote meta-C-H activation. This reaction provides a useful method for the modification of biaryl compounds because the nitrile group can be readily converted to amines, acids, amides, or other heterocycles. Notably, the remote meta-selectivity of biphenylnitriles could not be expected from previous results with a macrocyclophane nitrile template. DFT computational studies show that a ligand-containing Pd-Ag heterodimeric transition state (TS) favors the desired remote meta-selectivity. Control experiments demonstrate the directing effect of the nitrile group and exclude the possibility of non-directed meta-C-H activation. Substituted 2-pyridone ligands were found to be key in assisting the cleavage of the meta-C-H bond in the concerted metalation-deprotonation (CMD) process.

To develop advanced heat transfer composites, new sets of unsymmetrical calamitic molecules with a coumarin unit at one end and a biphenyl group at the other end were synthesised. Their structural characterisation was investigated by routine techniques such as CHN analysis, and FT-IR, and 1D, and 2D NMR spectroscopic techniques. The liquid crystalline properties of these molecules were investigated by POM and DSC along with XRD techniques. All target compounds exhibited mesomorphic behaviour. The smectic C phase was seen for all the compounds. To enhance their thermal conductivities, conductive nanofillers, such as boron nitride nanosheets (BNNSs) and aluminium oxide nanoparticles Al2O3, were added to the synthesised liquid crystals. The LCnanocomposites exhibit excellent thermal conducting performance when a combination of BNNSs and Al2O3 nanoparticles were added to the liquid crystals. The thermal conductivity of the 4i-BN35-A15 nanocomposite was 1.7 W/m K compared to 0.3 W/m K for the pure liquid crystal compound 4i. [ABSTRACT FROM AUTHOR]

A nonsteroidal drug called flurbiprofen (FBN) has analgesic, anti‐inflammatory and antipyretic activity. Currently the determination of FBN in cataplasm does not have any pharmacopeial method. However, the drug substance, tablet and ophthalmic solution formulations do have pharmacopeial methods. The development and validation of an accurate, precise and stability‐indicating analytical method for the determination of FBN in cataplasm formulations is reported. The gradient method was employed for the quantification of FBN in the presence of internal standards such as biphenyl. A nonpolar separation phase (C18, 250 × 4.6 mm, 5 μm Inertsil column; GL Sciences) was used. The optimal flow rate, column oven temperature, injection volume and detector wavelengths were 1.0 ml/min, 40°C, 20 μl and 245 nm, respectively. Mobile phase A was a mixture of water and glacial acetic acid (30:1 v/v) pH adjusted to 2.20 with glacial acetic acid or 1 m NaOH; mobile phase B was methanol (100%). The gradient elution program was [time (min)/% B]: 5/60, 20/70, 25/70, 30/60 and 40/60. The obtained RSDs for the precision and intermediate precision were 0.7 and 0.5%. The percentage recovery ranged from 99.2 to 100.4%. The linear regression coefficient >0.9996 indicates that all peak responses were linear with the concentration. The sample and standard solutions were stable for up to 24 h on the benchtop and in the refrigerator. The critical peaks were well separated from the generated peaks owing to forced degradation, including diluent and placebo peaks. The method validation data and quality by design‐based robustness study results indicate that the developed method is robust and fit for routine use in the quality control laboratory. The proposed method is specific, accurate and precise, and the quality by design utilized the first method for the determination of FBN in cataplasm formulations. Transdermal patches and gels have low extraction capacity and this method is applicable for quantification. [ABSTRACT FROM AUTHOR]

The Birch reduction of biaryls generally converts one of the two arenes into a cyclohexa-1,4-diene. Biaryls are more reactive than monocyclic arenes under the Birch conditions. Unlike the reduction of monocyclic arenes, biaryl reduction proceeds through two consecutive electron transfer steps before the protonation of the dianion intermediate. The biaryl reductions and subsequent alkylations in one pot rapidly increase the molecular complexity and thus have been used in the synthesis of natural products and drug-like molecules. 1 Introduction 2 The Physical Organic Chemistry of the Birch Reduction of Biaryls 3 Biaryls as the Mediators of Electron Transfer 4 Methods for the Dissolving-Metal Reduction of Biaryls 5 Intercepting the Biaryl Reduction Intermediates with Electrophiles 6 Synthetic Applications of the Dissolving-Metal-Mediated Reductions of Biaryls 7 Outlook [ABSTRACT FROM AUTHOR]

Aromatic hydrocarbon molecules with π-conjugated structure have great potential for the search of exotic states such as high temperature superconductivity and novel quantum magnetism. In this work, we found that high temperature weak ferromagnetism can be achieved by intercalating rubidium into the shortest poly(para-phenylene) molecule—biphenyl. Both dc and ac magnetic susceptibility measurements showed that the synthesized material exhibits a typical antiferromagnetic transition at 48.5 K, accompanying a ferromagnetic character in the magnetically ordered region. Combining theoretical calculations and Raman spectroscopic studies, it was found that the mole ratio between rubidium and biphenyl is 1:1, and the molecular magnetic moments are formed by transferring the Rb-5s electrons to the C-2p orbitals. The weak ferromagnetism is produced by intralayer spin-canted antiferromagnetic and interlayer ferromagnetic spin couplings. Our finding enriches the physicochemical functionality of biphenyl and opens a window for the search of π-electron organic magnets in poly(para-phenylene) molecules.

Quaternary phosphonium salts are popular candidates used in many chemical transformations and synthetic chemistry, notably in catalysis. We have examined the single crystals of two bulky phosphonium compounds, tetra([1,1′-biphenyl]-4-yl) phosphonium dicyanamide (C48H36P+·N(CN)2−, compound 1), and tetra([1,1′-biphenyl]-4-yl) phosphonium bromide hydrate (C48H36P+·Br−, CH3CN, H2O, compound 2), and herein report the structural properties for the compounds with an emphasis on the influence of the ion-ion interaction towards self-assembly; the overall self-assembly for both structures is very similar, with subtle differences in the cell parameters. The symmetrical tetra ([1,1′-biphenyl]-4-yl) phosphonium cations in both compounds self-assembled to form robust stacked columns in the solid-state, with voids occupied by anions or solvent molecules. Quantitative examination of intermolecular interactions using Hirshfeld surface analysis found that classical and non-classical hydrogen bonding appears to be the dominant contributor in stabilizing the self-assembly in both cases. The present work can not only benefit in understanding the mutual interaction between the sterically encumbered tetra ([1,1′-biphenyl]-4-yl) phosphonium cations and between counterions, but also provide insights for the self-assembled arrays in the solid-state. [ABSTRACT FROM AUTHOR]

• Biphenyl based Schiff base derivatives of 6-amino coumarin were designed and synthesized. • Lower alkoxy chain showed enantiotropic nematic mesophase in both the series. • Higher alkoxy chain showed stable enantiotropic SmA mesophase in both the series. • Compounds of both the series were studied by the DFT calculations for correlation of observed mesomorphic behaviour. The study focused on synthesizing two series of coumarin Schiff base liquid crystals. These series involved molecules with variations in alkoxy chains at aldehyde ends: one being the Schiff base with 4′‑hydroxy-[1,1′]-biphenyl-4-carbaldehyde (ASBP series) and the other being alkyl 4-formyl-[1,1′]-biphenyl-4-carboxylate (AEBP series). The compounds were characterized using FTIR, NMR, and Mass spectral analyses. All the compounds were studied for their mesomorphic properties, differential scanning calorimetry (DSC) and polarized optical microscopy (POM). In both the homologous series, variation of alkyl chain length showed intriguing phase transitions. In the first homologous series ASBP , compound with hexyloxy chain displayed an enantiotropic nematic (N) phase, while those with chain lengths n = 8–16 exhibited enantiotropic smectic A (SmA) mesophase. Similarly, in the AEBP series, compounds with n = 6,8 chain length showed an enantiotropic nematic (N) phase, while those with higher chain lengths n = 10–16 exhibited enantiotropic smectic A (SmA) phases. SmA mesophase was further confirmed by powdered XRD analysis. The study included DFT theoretical calculations to comprehend the compounds' mesomorphic behavior, comparing them with analogous reported compounds. Additionally, the investigation correlated experimental findings of individual compounds with calculated parameters like polarizability, dipole moment, and aspect ratio. Molecular electrostatic potential projections and analysis of frontier molecular orbitals were also employed to elucidate how polarity variations in terminal chains and mesogenic cores influenced the energy gap of FMOs and the distribution of electrostatic charges on these compounds. It has been found that the ASBP series has lower energy gap and higher dipole moment than the AEBP series. [Display omitted] [ABSTRACT FROM AUTHOR]

Clusiaceae plants contain a wide range of biologically active metabolites that have gotten a lot of interest in recent decades. The chemical compositions of these plants have been demonstrated to have positive effects on a variety of ailments. The species has been studied for over 70 years, and many bioactive compounds with antioxidant, anti-proliferative, and anti-inflammatory properties have been identified, including xanthones, polycyclic polyprenylated acylphloroglucinols (PPAPs), benzophenones, and biphenyls. Prenylated side chains have been discovered in many of these bioactive substances. To date, there have been numerous studies on PPAPs and xanthones, while no comprehensive review article on biphenyls from Clusiaceae has been published. The unique chemical architectures and growing biological importance of biphenyl compounds have triggered a flurry of research and interest in their isolation, biological evaluation, and mechanistic studies. In particular, the FDA-approved drugs such as sonidegib, tazemetostat, daclatasvir, sacubitril and trifarotene are closely related to their biphenyl-containing moiety. In this review, we summarize the progress and development in the chemistry and biological activity of biphenyls in Clusiaceae, providing an in-depth discussion of their structural diversity and medicinal potential. We also present a preliminary discussion of the biological effects with or without prenyl groups on the biphenyls.

Five compounds were isolated from the methanolic extract of Caesalpinia sinensis stems and leaves including a new cassane-type butenolide norditerpenoid compound (1) and a new type of biphenyl compound (2); the compounds were identified as Norcaesalpin-one (1), 4'-hexyl 3-methyl 6-methoxy-[1,1'-biphenyl]-3,4'-dicarboxylate (2), rhapontigenin (3), 3-deoxysappanchalcone (4), isoliquiritigenin (5). Compounds 1-5 were first isolated from C. sinensis. Their structures were elucidaded on the basis of MS, IR, NMR spectroscopic, X-ray diffraction data analyses. The NGF-induced PC12 differentiation assay was performed on compound 1, and the results showed that compound 1 had a promotive effect on PC12 cell differentiation, with a differentiation rate of 12.32%. In addition, compounds 1-5 were evaluated for their cytotoxic activities against four human cancer cell lines (including A-549, BGC-823, MDA-MB-231, HepG2), and the results showed that compounds 3-5 showed inhibitory activity against these cancer cell lines with IC50 values ranging from 22.96 to 74.92 μmol/L, compound 4 showing the best activity against human malignant melanoma cells A375 with an IC50 value of 22.96 μmol/L. [ABSTRACT FROM AUTHOR]

Angiotensin converting enzyme (ACE) and a-amylase inhibitors were synthesized using 40-(bromomethyl)-biphenyl-2-carbonitrile 1 and various cyclic secondary amines (a–h). The nitrile group appended to biphenyl was converted into tetrazole 3a–3h and the tetrazole was ring transformed into 1,3,4-oxadiazole derivatives 4a–4h. Some of the compounds have exhibited significant ACE and a- amylase inhibition. [ABSTRACT FROM AUTHOR]

In this work, biphenyl was used as carbon source to enrich microorganisms from polychlorinated biphenyls (PCBs)-contaminated paddy soil samples, and the taxonomic structures in both of the soil samples and the fourth-generation enrichments were examined with high-throughput sequencing. Single cells were isolated from the enrichments via single cell sorting technology named Laser Induced Visualized Ejection Separation Technology (LIVEST) and also traditional single colony sorting, and the genera of the isolates were identified using 16S rRNA sequencing. The results from high-throughput sequencing present that enrichment from generation to generation can considerably change the microbial community. Comparing the two sorting methods, the LIVEST is more time-saving and cell-targeted for microbial resource exploration. Based on the further verification of biphenyl degradation, it was found that some strains belonging to genera Macrococcus, Aerococcus and Metabacillus are capable in degrading biphenyl, which have not been reported yet. [ABSTRACT FROM AUTHOR]

A series of poly(p‐phenylenevinylene) (PPV) type dyes: QoBp, QoBm, QpBp, and QpBm containing biphenyl (B) and 8‐alkoxyquinoline (Q) moieties connected at either ortho (o) or para (p) position are synthesized for the application of organic light‐emitting diodes. The structure design takes the advantages of the good luminescent property of biphenylvinylene and the electron transporting nature of quinolinol. Two polymeric materials: poly‐QoBp and poly‐QoAp were also prepared, whereas the biphenyl moiety of the latter was replaced by a para‐hydroquinone (Ap) moiety. All compounds exhibited high thermal stability with Td values exceeding 300°C. A typical blue light device made with QoBp showed a turn‐on voltage of 4 V, a maximal intensity of 2.30 × 103 cd/m2 at 20 V, and a highest external quantum efficiency (EQE) of 0.43%. Devices of the polymers were made by doping into PVK. The device made with poly‐QoBp exhibited a turn‐on voltage of 9.5 V, and a maximal intensity of 360 cd/m2 at 15 V. A white light device was made successfully by the combination of the blue emission of QoBp and the red emission of 2,3‐bisindolyl‐N‐methylmaleimide. It showed a maximal intensity of 940 cd/m2 at 15 V with a highest EQE of 0.14%. [ABSTRACT FROM AUTHOR]

Solid–liquid equilibria for binary mixtures formed by biphenyl and n-tetracosane and ternary mixtures formed by n-tetracosane + dibenzofuran + biphenyl were experimentally determined using differential scanning calorimetry (DSC). The liquidus lines were established from the onset temperatures of the melting peaks observed in the thermograms. The experimental data were compared to predictions made by a thermodynamic model considering ideal solution. Non idealities were also computed by means of the group contribution method UNIFAC. Original UNIFAC and several modifications such as UNIFAC-Lyngby and UNIFAC-Dortmund versions were assessed. The polymorphism phenomenon was considered and the heat capacity contribution was supposed to be negligible since the involved compound have nearby melting points. The best description is obtained with UNIFAC-Lyngby method, which leads to the lowest deviations in melting temperature and activity coefficients. This work contributes to acquire knowledge about solid–liquid phase behavior of multi-components systems containing heavy n-alkanes and aromatics, which is scarce in literature. [ABSTRACT FROM AUTHOR]

The current mainstream energy storage systems are in urgent need of performance improvements to meet novel application requirements. In pursuit of a higher energy density in Li-ion and Na-ion batteries, the conventional electrode materials have reached the upper limit of their theoretical specific capacities. Hence, facile methods of reducing irreversible lithium-ion/sodium-ion loss are developed to further boost the battery energy density. Herein, we review studies that use polycyclic aromatic hydrocarbons for wet chemical prelithiation and presodiation. The molecular structures of arenes and solvents used for solution-based prelithiation/presodiation have a substantial impact on the prelithiation/presodiation power and effectiveness. Multiple reports have already shown excellent initial Coulombic efficiency and streamlined processes by using this type of wet chemical prelithiation/presodiation strategy. This review article will cover how to select appropriate polycyclic aromatic hydrocarbon prelithiation/presodiation reagents for various materials/electrodes and provide possible directions and guidelines for future works. [ABSTRACT FROM AUTHOR]

The development of whole-body inhalational chambers for acute toxicity risk assessment of aerosols in rodents is of key importance in clinical and occupational hazard evaluations. The key aim of study is the design, development, optimization, and validation of an inhalational chamber using water aerosol, vehicle, and Aroclor 1232. The second goal has been to apply this chamber in the risk assessment of Aroclor 1232. Broncho-alveolar Lavage fluid cytology and chromatography, and lung histopathology were used to supplement the validation process. PCB concentrations were uniformly distributed across different places inside the chamber and a MMAD generation of 4.3 µm ± 1.7 µm GSD was suggestive of lower airway atomization of PCB particles. The chamber environmental parameters were within acceptable limits for rodents during the experimental procedures. Mouse behavioral alterations were minimal during water aerosolization. Acute exposure to Aroclor 1232 showed reproducibility of behavioral scores. Benchmark dose for further studies using Aroclor 1232 was derived at 4 mg/cu.m. Its toxicities could be verified by correlating the behavioral scores, neurobehavioral functions with concentrations in plasma and BAL fluid samples from Swiss albino mice. The rodent chamber can be utilized for risk assessment of occupational hazards such as complex pollutant mixtures and particulate matter aerosols. The inhalational chamber possesses the versatility to enable assessment of toxicological mixtures across sub-acute toxicity timelines. [ABSTRACT FROM AUTHOR]

The click chemistry approach, namely Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC), has been employed to generate a library of 2-{4-[([1,1′-biphenyl]-2-yloxy)methyl]-1H-1,2,3-triazol-1-yl}-N-(sub-stituted phenyl)acetamides 7a–7j through a four-step procedure. The influence of different halogen substituents on the antibacterial properties of the synthesized compounds against Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans has been tested using ampicillin and fluconazole as reference drugs. Among the synthesized biphenyl–triazole hybrids, fluorine-substituted systems were found to be more active than those bearing other halogen atoms. [ABSTRACT FROM AUTHOR]

Three novel D-π-π-A prototype compounds, namely, (E)-2-(3-([1,1'-biphenyl]-2-yl)-1-(9H-fluoren-2-yl)allylidene)malononitri-le (2-BAM), (E)-2-(3-([1,1'-biphenyl]-3-yl)-1-(9H-fluoren-2-yl)allylidene)malononitri-le (3-BAM), and (E)-2-(3-([1,1'-biphenyl]-4-yl)-1-(9H-fluoren-2-yl)allylidene)malononitri-le (4-BAM) were synthesized. Furthermore, the structures and photophysical properties of three compounds were compared. Molecules of 2-BAM were packed into a 1D column structure with H-aggregation. However, both of 3-BAM and 4-BAM were packed into 3D layer structures with J-aggregation, respectively. Although all three compounds showed highly twisted molecular geometries, their respective molecular packing and intermolecular interactions were different. Because of the differences in electronic structures of molecules, three compounds displayed different emission behaviors in solid and dilute solution states. This study indicated that changing the position of biphenyl groups is an effective way for turning the structures and photophysical properties of such D-π-π-A prototype fluorescent materials. [ABSTRACT FROM AUTHOR]

Liquid organic hydrogen carriers (LOHCs) relying on eutectic diphenylmethane-biphenyl mixtures feature advantageous characteristics such as low melting points and large hydrogen storage capacities. For contributing to a reliable database of process-relevant thermophysical properties, the present study investigates the viscosity, surface tension, and density of the LOHC-system based on diphenylmethane, biphenyl, and benzophenone between (278 and 573) K. General agreement between the viscosity and surface tension results from surface light scattering and the data from capillary viscometry and pendant-drop tensiometry is found. Larger surface tension differences beyond 10% for systems containing benzophenone seem to originate from surface orientation effects. For the eutectic diphenylmethane-biphenyl mixture including its hydrogenated dicyclohexylmethane-bicyclohexyl analog, the densities, surface tensions, and viscosities are not significantly different from those of the corresponding pure compounds. By gradually replacing diphenylmethane by its oxidized form benzophenone in mixtures with biphenyl, an increase in density, surface tension, and especially viscosity is observed. [Display omitted] • Study of properties of LOHC system based on eutectic mixtures of H0-DPM and H0-BP. • Surface light scattering and conventional methods applied between 278 and 573 K. • Contribution to extended database for viscosity, surface tension, and density. • Eutectic mixture and its hydrogenated analog show properties similar to pure fluids. • Presence of benzophenone as oxidized form of H0-DPM increases especially viscosity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Strong Electrostatic Adsorption (SEA) strategy produces finely dispersed Ni-Ru catalyst. • Enhancing metal-support interaction forms Niδ+ sites, enabling electron-rich aromatics adsorption. • Ru addition enhances hydrogen spillover and Ni dispersion. • SEA catalyst shows increased cyclohexylbenzene conversion and turnover frequencies. Tuning the metal-support interaction (MSI) between highly dispersed nanosized metal particles and the support plays a pivotal role in the activity and selectivity of polyaromatics selective hydrogenation. In this work, the supported bimetallic Ni-Ru/SiO 2 -SEA catalyst was prepared by a strong electrostatic adsorption (SEA) strategy, and applied for the selective hydrogenation of biphenyl (BP) to cyclohexylbenzene (CHB). Compared to the catalysts prepared by the conventional incipient wetness impregnation method and Ni/SiO 2 -SEA, the significant effects of MSI and hydrogen spillover on Ni-Ru/SiO 2 -SEA facilitated the highly exposed and uniformly dispersed electron-deficient Niδ+ (0 < δ < 2) species, which could enhance adsorption and activation of the electron-withdrawing phenyl group and H 2 , thereby promoting the efficient and selective conversion of BP to CHB. At the conditions of 160 ℃ and 2 MPa H 2 pressure, BP conversion over Ni-Ru/SiO 2 -SEA reached nearly 100 % within 3 h, achieving a remarkable selectivity of 97.9 % towards CHB, along with a high turnover frequency of 2756.9 h−1 for the active metallic Ni sites. Importantly, according to the kinetic simulations, the hydrogenation rate constant of Ni-Ru/SiO 2 -SEA was the highest (2.76 × 10-2 mol·g−1·h−1) among the employed catalysts. Moreover, after six consecutive cycles, no obvious decline in hydrogenation efficiency was observed, confirming the remarkable activity and stability of Ni-Ru/SiO 2 -SEA. Furthermore, the activation of BP and desorption of CHB pathway on the Niδ+ species were elaborated through temperature-programmed desorption characterization, highlighting the prominent contribution of MSI in enhancing the selective hydrogenation of polyaromatics. [ABSTRACT FROM AUTHOR]

A series of new fluorinated copoly(ether imide)s containing pyridyl and biphenyl moieties were prepared by thermal imidization of poly(amic acid)s derived from 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (BATB), 4-(4-trifluoromethylphenyl)-2,6-bis(4-aminophenyl)pyridine (TFMPBPP) and 3,3',4,4'-biphenyltetracarboxylic dianhydride with various mole ratios of BATB and TFMPBPP ranging from 80/20 to 20/80. All copoly(ether imide)s were amorphous and soluble in polar solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone at room temperature or upon heating at 70 °C, and displayed good thermal properties with gradually increasing of a glass transition temperature ranged from 282 to 347 °C as an increase of the TFMPBPP component, the temperature at 5% weight loss of 574–586 °C, and the residue of 57–62% at 750 °C in nitrogen. Tough and flexible polymer films also exhibited outstanding mechanical properties with tensile strengths of 109.1–111.9 MPa, tensile moduli of 1.3–1.5 GPa, and elongations at break of 27.9–48.7%, low dielectric constants of 2.98–3.15 (1 MHz) and water uptake 0.36–0.55%, as well as high optical transparency with the UV-vis cutoff wavelength in the 370–382 nm range and the wavelength of 80% transparency in the range 518–550 nm. [ABSTRACT FROM AUTHOR]

2,7-Substituted fluorenone has a planar and slightly bent aromatic structure and is used as a building block for organic liquid crystals (LCs). Herein, we report for the first time the synthesis, phase-transition behaviour, and mesophase structure of fluorenone-incorporated LC trimers that exhibit an emerging helical twist-bend nematic (NTB) phase. The LC trimers possess a central 2,7-ether-substituted fluorenone and bilateral cyanobiphenyl groups linked via odd alkylene CnH2n spacers (n = 7 or 9) with either ether or thioether outer linkages; these are abbreviated CBOnOFlnOnOCB and CBSnOFlnOnSCB, respectively. The CBOnOFlnOnOCB trimers having only ether linkages display only the conventional nematic (N) phase, whereas the outer thioether-linked CBSnOFlnOnSCB trimers form an NTB phase below the temperature range of the N phase. Furthermore, the phase-transition behaviour of these fluorenone-based LC trimers is compared with that of the corresponding all-biphenyl-based motif trimer analogues, CBOnOBOnOCB and CBSnOBOnSCB. [ABSTRACT FROM AUTHOR]