Benzene Research Articles

Synthesis and antioxidant activity of 14-Aryl-14H-dibenzo[a,j] xanthene’s and bis(3-hydroxy-5,5′-dimethyl-2-cyclohexene-1-ones) derivatives using silica-tungstosulfonic acid catalyst

The synthesis of biologically active benzoxanthene, and bis(3-hydroxy-5,5’-dimethyl-2-cyclohexene-1-ones) derivatives has been conducted under an environmentally benign method by using an efficient catalyst, silica-tungstosulphonic acid. The benefits of this catalyst include being safe for the environment, low-cost, and simple to construct. It produces good yields and high purity in a short time and facilitates easy cleansing, products are obtained by straightforward recrystallization without the need for column chromatography. The reagent retained its catalytic activity for at least five consecutive cycles of reuse. The catalyst is described by IR, XRD, and SEM-EDX, which clearly shows that sulfonation happens in silica tungstic acid. In addition, the targeted derivatives were studied for anti-oxidant properties such as DPPH, reducing power assay, and H2O2 scavenging activity. The synthesized products such as 3e, 5k, 5 m, 5o, and 5p showed good anti-oxidant properties. Among all of these compounds, 5p showed good activity due to the nitro substitution on the benzene ring.

Organophotocatalytic Reduction of Benzenes to Cyclohexenes.

The reduction of abundant benzene rings to scarce C(sp3)-rich motifs is invaluable for drug design, as C(sp3) content is known to correlate with clinical success. Cyclohexenes are attractive targets, as they can be rapidly elaborated into large product libraries and are stable against rearomatization. However, partial reduction reactions of benzenes to cyclohexenes are rare and have a very narrow scope. Herein we report a broadly applicable method that converts electron-poor benzenes to cyclohexenes and tolerates Lewis-basic functional groups such as triazoles and thioethers as well as reducible groups such as cyanides, alkynes, and sulfones. The reaction utilizes an organic donor that induces mild arene reduction by preassociation to a photoexcitable electron donor-acceptor (EDA) complex and mild isomerization of redox-inert 1,4-cyclohexadienes to reducible 1,3-cyclohexadienes without a strong base in its oxidized thioquinone methide form.

Novel Meta-Diamide Derivatives Bearing Triazole: Design, Synthesis and Bioactivity.

In searching for novel insecticide lead,20new meta-diamidecompounds containingtriazole were designed and synthesized regardingCyproflanilide aslead compound.All the compounds were characterized by 1HNMR,13CNMR and HRMS.In preliminary bioassay, we found that one of the compounds: N-(cyclopropylmethyl)-N-(5-((2,6-dibromo-4-(1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl)phenyl)carbamoyl)-2-(1H-1,2,4-triazol-1-yl)phenyl)-6-(trifluoromethyl) nicotinamide(16a) had high activity against the target organism Plutella xylostellaat 1 mg/L and against the target organism Mythimna separataat 2 mg/L. It is obviously superior to theknowncompoundsⅠaand Ⅰb, and itisequivalent to cyproflanilide, the LC50values of the compound against P. xylostella and M. separata were 0.90 mg/L and 0.64 mg/L respectively. It is providing important clues for subsequent structure-activity relationship studies. From this, we explored the structure-activity relationship of these compounds. Through comprehensive analysis of their structural characteristics and insecticidal activity data, we found that different halogen substituents on benzene ring and different aromatic substituents on amino group in the compound had significant effects on insecticidal activity. This has certain guiding significance for further structural optimization and activity enhancement.

A Comprehensive Review on Construction of Biologically Active α‐Carbolines From Synthetic And Natural Origin.

Abstractα‐Carboline is an important scaffold present in various synthetic and naturally obtained bioactive compounds possessing a wide range of pharmacological properties. Hence, in the current comprehensive review, we intend to present the main routes to the synthesis of α‐carboline analogs based on various pathways such as pyrrole, benzene, and pyridine ring annulation. The pathways include either or combinations of transition metal‐catalyzed amination/arylation, Graebe‐Ullmann reaction (thermal pyrolysis, photochemical cyclization), Diels‐Alder cycloaddition and condensation reactions, N‐Heterocyclic carbene catalysed reactions, decarboxylative annulation, etc. of substituted benzene, pyridine, quinoline, and indole derivatives in order to compare the potential of synthetic routes of this series and consolidate the development, current status and perspectives for the design of α‐carboline analogs. Various pharmacological and spectroscopy functions of the compounds belonging to this class are summarized herewith. It also discusses the synthesis of functionalized bioactive naturally obtained hetero‐annulated α‐carbolines.

Phycogenic nanoparticles efficiently catalyse pesticide degradation through a novel metabolic pathway utilizing solar light

Cypermethrin (Cy) is a widely used insecticide, leading to significant environmental contamination in homes and agricultural areas. Effective methods to minimize or eliminate insecticidal residues are essential. Seaweeds, traditionally used in agriculture as soil conditioners, offer a promising solution for remediating pesticide-contaminated soils through biogenic nanoparticle synthesis. In this study, we synthesized biogenic silver nanoparticles (UL-AgNPs) from the green seaweed Ulva lactuca Lin (Ulvaceae) to degrade Cypermethrin. The UL-AgNPs were characterized using UV-Visible spectroscopy, Scanning Electron Microscopy equipped with Energy dispersive X-ray spectroscopy, Fourier Transform Infra-red spectroscopy, X-ray diffraction, Dynamic light scattering and zeta potential analysis, confirming their presence, size (81.29 nm), structure and stability. Response surface methodology (RSM) was used to assess the catalytic concentration of photocatalyst for degradation of pesticide including variables, Cy concentration and destined exposure time duration. The degradation efficiency of UL-AgNPs was evaluated, with the highest degradation (91.2%) achieved at pH 7 after 12 hours using 16.6 mg L-1 of UL-AgNPs, following pseudo-first order kinetics with a rate of 2.7 hour-1. GC-MS and UV-Visible spectroscopy revealed a novel degradation pathway, where Cypermethrin was broken down into compounds like Tetradecane, Dodecane, and Tetracosanoic acid through ester cleavage and benzene ring breakdown. The study also demonstrated the reusability of UL-AgNPs for four cycles, highlighting their potential for sustainable environmental management by reducing the long-term hazards of Cypermethrin.

Probing the potential mechanism of permethrin exposure on Alzheimer's disease through enantiomer-specific network toxicology, multi-spectroscopic, and docking approaches

Latest observations indicated that exposure of organic environmental neurotoxins may increase the potential risk of Alzheimer's diseases (AD). As a suspected food-derived risk factor, permethrin, composed of cis-isomer and trans-isomer, is widely used as a broad-spectrum pyrethroid insecticide in agricultural crops for the arthropod pests controlling. Thus, evaluating the impact of permethrin exposure is of great importance to human health. In this study, we performed the toxicological network approach to decipher AD-related mechanisms of cis-permethrin and trans-permethrin. Based on the toxicological network construction and central network topological analysis, human serum albumin (HSA) was selected as the core targets in AD-related developing. From the analysis of the steady state and time-resolved fluorescence quenching of HSA in presence of permethrin mixture, it has been inferred that the nature of the quenching mainly originates from the dynamic modes. Experimentally, the thermodynamic parameters revealed hydrophobic interactions and van der Waals forces played a major role during quenching process. Tryptophan synchronous fluorescence spectra were blue shifted whereas the position of tyrosine synchronous spectra was red shifted during the complex formation. Three-dimensional fluorescence together with FT-IR experiment confirmed that permethrin caused the secondary structure changes in HSA. To better understand the binding patterns between HSA and cis/trans -permethrin, theoretical calculation and molecular docking were implemented. According to the electrostatic potential map, the electrophilic attack region corresponds for electron rich oxygen atoms, while the nucleophilic attack regions were mainly located at over the benzene rings and methyl on cyclopropane ring of permethrins. Docking results shown that cis-permethrin and trans-permethrin located in hydrophobic pocket nearby Domain IIA with the different binding affinity (−7.6 and −9.2 kcal/mol), which consistent with the competitive displacement experiment. All these findings generated in the present study facilitated the elucidation of the molecular mechanism details between permethrin mixture and HSA, which provided fresh insights into the links between environmental exposure and AD-related adverse health outcomes.

The Catalysts-Based Synthetic Approaches to Quinolines: A Review.

The most common heterocyclic aromatic molecule with potential uses in industry and medicine is quinoline. Its chemical formula is C9H7N, and it has a distinctive double-ring structure with a pyridine moiety fused with a benzene ring. Various synthetic approaches synthesize quinoline derivatives. These approaches include solvent-free synthetic approach, mechanochemistry, ultrasonic, photolytic synthetic approach, and microwave and catalytic synthetic approaches. One of the important synthetic approaches is a catalyst-based synthetic approach in which different catalysts are used such as silver-based catalysts, titanium-based nanoparticle catalysts, new iridium catalysts, barium-based catalysts, iron-based catalysts, gold-based catalysts, nickel-based catalyst, some metal-based photocatalyst, α-amylase biocatalyst, by using multifunctional metal-organic framework-metal nanoparticle tandem catalyst etc. In the present study, we summarized different catalyst-promoted reactions that have been reported for the synthesis of quinoline. Hopefully, the study will be helpful for the researchers.

Covalent triazine frameworks as particle electrode for three-dimensional photoelectrocatalytic degradation of oxytetracycline: Synergy effects, pathway, and mechanism.

Photoelectrocatalysis has been widely employed for degrading antibiotics due to its high efficiency. However, the application is significantly impeded by the rapid recombination of photogenerated charge carriers and the limited surface areas of photoelectrodes. In the study, high crystallinity covalent triazine frameworks were fabricated at low temperature of 150°C and firstly used as particle photoelectrode in the three-dimensional photoelectrochemical reactor to degrade oxytetracycline (OTC). SEM, TEM, XRD, XPS, and FT-IR confirmed the successful synthesis of high crystallinity covalent triazine frameworks. Compared to CTF-120 (71.2%) and CTF-180 (46.9%), CTF-150 exhibited excellent OTC removal. Electrochemical impedance, UV-vis absorption spectra, and Mott-Schottky tests showed that CTF-150 demonstrated more wide light absorption range of 501nm and narrow bandgap of 2.52eV, and smaller Rct value under illumination, in comparing to CTF-120 and CTF-180. When the initial concentration of OTC was 50mgL-1, the 86.2% of OTC removal and 62.7% of mineralization were obtained under light irradiation (λ>420nm), current of 10mA, pH of 6.4, electrolyte of 0.1M Na2SO4. The synergy effect between photocatalytic and electrocatalytic processes of CTF-150 not only enhanced by 38.5% current efficiency but also reduced energy consumption to 1.90 kWh m-3. CTF-150 had a wide range of acid-base application and displayed resistance on coexisting ions. Electron spin resonance detection, quenching experiments, and probe experiments illustrated that h+, •O2-, 1O2, and •OH contributed to the degradation of OTC and the generation pathways of •O2-, 1O2, and •OH were verified. Moreover, •O2-, 1O2, and h+ were the main reactive species responsible for OTC removal, while 1O2 was for OTC mineralization. Based on high-performance liquid chromatography-tandem mass spectrometry detection, OTC with benzene ring was decomposed to opening ring products. The acute toxicity, developmental toxicity, bioaccumulation factor and mutagenicity of OTC and its intermediates using T.E.S.T. showed the toxicity of 82.35% degradation products decreased.

A simple and versatile photothermal dual-curing system design based on phytophenol derivatives and thiol chemistry for potential electronic encapsulant application

Given the diversity of thiol chemistry, researchers are actively exploring its potential as a versatile compound. This paper presents the synthesis of three bio-based multifunctional monomers (EPMG, EPBEG, EPBEF) containing allyl and epoxy groups using phytophenols (magnolol and eugenol) as raw materials. Photothermal dual curing was performed using pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). Comprehensive studies and comparisons of the cured systems were conducted, including curing kinetics, mechanical properties, dielectric properties, and transmittance. The effect of the curing sequence was systematically investigated. The results demonstrate that as the curing proceeds, the mechanical properties and glass transition temperature (Tg) of the material improve significantly, and the dual curing process exhibits excellent bonding, dielectric, and ultraviolet (UV) shielding performance. Moreover, the differences in monomer structure (methoxy, benzene ring connection) also impact the properties of the monomers and the performance of the material. This work provides a novel approach to designing epoxy monomer structures and developing bio-based single-component dual-curing systems. This thiol-mediated dual-curing system has potential applications in electronic materials and personal protective equipment can contribute to achieving miniaturization, precision, and integration in various applications.

Surface- and substrate-coated catalytic membrane for mitigating interference of water matrix species in intensified micropollutant confinement oxidation

The integration of advanced oxidation processes (AOPs) with membrane technology offers benefits for catalyst recovery and reducing membrane fouling. However, the application of the hybrid process could be hampered by the background species in water matrix. This study addresses this challenge by developing catalytic ceramic membranes (CCMs) with dual mechanisms to intensify acetaminophen (ACT) removal in water. The CCMs effectively activated peroxymonosulfate (PMS), achieving ACT degradation of 85% and 93% in real water matrices (reverse osmosis retentate and settled water, respectively) and 99% in MQ water. The CCMs demonstrated consistent performance across multiple operational cycles, even in the presence of humic acid (HA) (96% ACT reduction). The CCM design features Co3O4 catalytic layer on CCM surface, facilitating surface oxidation, reducing fouling, and TiO2 intermediate rejection layers serving as barrier for bulk organic pollutants, achieving 50% HA removal through rejection and 70% with 1.5mM PMS. This design facilitates catalytic degradation at the membrane surface, allowing retention and degradation of bulk organic pollutants and intermediates, while ACT permeates into CCM substrate. The surface oxidation and rejection enhanced confinement oxidation within the Co3O4-coated macropores, minimizing interference from background species. LC-QTOF analysis identified multiple degradation pathways, including hydroxylation, acetyl-amino group cleavage, side chain oxidation and benzene ring cleavage, with intermediates showing reduced toxicity. Reactive oxygen species involved in the system were identified and PMS activation mechanism was proposed. This research highlights the potential of the hybrid process, enhancing micropollutant removal by mitigating interference from background species, providing practical implications in water treatment applications.

Rubber-assisted and modulated epoxy topological network for developing fatigue-resistant, high-strain-cycle high performance shape memory polymer composites

High performance shape memory polymer (HPSMP) has a wide range of application such as smart device, smart mold. In this study, we designed a rigid-flexible shape memory epoxy with flexible chain segment as the main chain and rigid benzene ring as the side group. Meanwhile, carboxyl-terminated nitrile butadiene rubber (CTBN) was accessed into the epoxy main chain as a fatigue-resistant functional filler. The results showed that the flexible backbone plays a major role in improving the ductility. The superior fatigue-resistant shape memory cycling performance was synergistically achieved by modulating the epoxy topological network through altering the disulfide cross-linker prompted by CTBN, and the materials exhibited good high and low-temperature resistant mechanical properties. Comparatively, it is found that disulfide bonding can significantly improve the tensile property and thermal stability for epoxy. The synergistic effect between the elastic chain segments in CTBN and the flexible backbone achieves excellent shape recovery ratio. Therefore, the rational structural design provides an effective way to develop HPSMP, which can expand the application areas for HPSMP.

Theoretical research of the NO and N2O reduction by char in oxy-fuel CFBC: Influence of H2O

Oxy-fuel CFBC has lower NOx emissions compared to air combustion, with the high H2O content affecting NO and N2O reduction. This study, using density functional theory and transition state theory, investigates the impact of H2O on the char model at the electronic level and its subsequent influence on NO and N2O reduction. Results reveal that H2O adsorbs onto the active site on char, forming hydroxyl groups and free H atoms. The unstable O atom in –OH group leads to benzene ring rearrangement in the char model, creating additional active sites. NO reduction follows two paths: producing CO(R1) or CO2(R2). For N2O reduction(R3), N2O reduction precedes benzene ring cracking, with CO2 production providing more active sites. In R1, CO formation limits reactive sites and increases activation energy, while R2 and R3 favor CO2 formation. Reaction pathways leading to CO2 formation show lower activation energies and higher pre-exponential factors for N2 release.

Synthesis and Characterization of Polyimide with High Blackness and Low Thermal Expansion by Introducing 3,6-bis(thiophen-2-yl)diketopyrrolopyrrole-Based Chromophores

The market demand for black polyimide (BPI) has grown hugely in the field of flexible copper-clad laminates (FCCLs) as a replacement for transparent yellow polyimide. The 3,6-bis(thiophen-2-yl)diketopyrrolopyrroles (TDPP) derivative is recognized for its high molar extinction coefficient. In this research, we have synthesized a diamine monomer named 3,6-bis[5-(4-amino-3-fluorophenyl)thiophen-2-yl]-2,5-bis(2-ethylhexyl)pyrrolo[4,3-c]pyrrole-1,4-dione (DPPTENFPDA), featuring a TDPP unit attached by fluorinated benzene rings. The subsequent reaction of DPPTENFPDA with pyromellitic dianhydride (PMDA) yielded an inherent BPI (DPPTENFPPI). By introducing chromophores derived from TDPP, the light absorption spectrum of DPPTENFPPI was broadened and red-shifted, thereby achieving full absorption within the visible spectrum and producing a highly black color that has a cut-off wavelength (λcut) of 717 nm and a CIE-Lab coordinate L* of 0.86. Additionally, DPPTENFPPI exhibited a low coefficient of thermal expansion (CTE) and remarkable thermal and electrical performance. Density functional theory calculations were conducted to explore the electronic nature of DPPTENFPPI. The outcomes revealed that the excellent light absorption of DPPTENFPPI predominantly originates from the transition from HOMO to LUMO + 1 within the chromophore moiety. The FCCL made from DPPTENFPPI films has high solder heat resistance and peel strength. This research contributes valuable insights into the structure and design of high-performance intrinsically black PIs for microelectronics applications.

Efficient fabrication of chitin-based films with high UV-blocking and fluorescence via Hantzsch reaction

As the second most abundant polysaccharide on earth, chitin-based films are promising packaging and biomedical materials. However, the lack of special function (especially UV-blocking properties and fluorescence) usually restricts their further and high-value applications. Herein, high UV-blocking and fluorescence chitin-based films were fabricated via surface modification using acetoacetation and the Hantzsch reaction. The structure and properties of the films were characterized by NMR, FTIR, fluorescence spectrum, and tensile tests. The results showed that the benzene ring and 1,4-dihydropyridine ring (DHP) were successfully grafted on the films in the mild process. Besides, the degree of substitution of DHP (DSDHP) increased with the reaction time, temperature, and substrate concentration. Moreover, the modification followed a first-order reaction at 20 °C with a rate constant of 2.1 × 10−4. When the DSDHP was over 0.029, the films exhibited 100 % UV shielding. The fluorescence spectrum demonstrated that the films had excellent solvent and temperature resistance. In addition, the films exhibited excellent mechanical strength with tensile strength up to 85.2 MPa. This work provides a facile and environmentally friendly strategy to fabricate a functional chitin-based film with potential applications in UV protection, medical packaging, and fluorescent materials.

The influence of pH on the liquid-phase transformation of phenolic compounds driven by nitrite photolysis: Implications for characteristics, products and cytotoxicity

The aqueous-phase conversion of phenolic compounds (PhCs) driven by nitrite photolysis has been recognized as a significant source of secondary brown carbon (BrC). However, the influence of pH on the conversion kinetics and product distribution of PhCs remains unclear. In this study, three representative PhCs with varying functional groups were selected to examine their aqueous-phase conversion kinetics in the presence of nitrite under different pH conditions and simulated sunlight conditions. The results indicate that as the pH increases, the decay rates of PhCs decrease, following first-order reaction kinetics. These varying decay rates also suggest that different substituents on the benzene ring significantly impact the reactivity of PhCs. The molecular composition of the products is pH-dependent, with 4-nitrocatechol (4NC) emerging as the primary reaction product. A range of conversion products were detected across different pH values: nitrification dominated at low pH, while hydroxylation products increased with rising pH, and polymerization products appeared prominently at high pH. Due to the electron-withdrawing effect of the nitro group on the benzene ring, fewer products formed from 4-nitrophenol were observed, and the visible absorption spectrum also showed a decreasing trend as the reaction progressed across various pH conditions. Toxicity assays on human non-small cell lung cancer cells (A549) revealed that the toxicity of the reaction products decreased with increasing pH. Correspondingly, the accumulation of reactive oxygen species (ROS) and apoptosis rates in cells also declined. This may be due to the fact that at lower pH levels, nitrophenols (NPs), which tend to promote ROS accumulation and cell death, dominate the product mix. This study provides valuable insights into the toxicological properties of secondary organic aerosols (SOA) formed from the photo-oxidation products of PhCs under different pH conditions. These findings contribute to a deeper understanding of the environmental and health impacts of SOA in atmospheric chemistry.

Dibutyltin dilaurate catalysed guar gum and toluene diisocyanate polyurethane foam for the removal of malachite green from wastewater

AbstractIn view of the huge potential in various applications, biopolymer‐based polyurethane foams (PUF) are attracting researchers. In the present study, we report the modification of guar gum (GG) via polyaddition reaction with toluene diisocyanate (TDI) using dibutyltin dilaurate as catalyst, silicone oil as surfactant and calcium carbonate as filler to form GG‐PUF. The as‐synthesized GG‐PUF was characterized by Fourier transform infrared (FTIR), XRD, field emission SEM, energy‐dispersive X‐ray spectroscopy, and surface charge analysis. In the FTIR spectrum of GG‐PUF, peaks at 3290, 1705, 1595, and 1510 cm−1 are attributed to stretching vibrations of –NH, –C=O, –C=C– of the benzene ring of TDI, and the –NH bending vibration of the urethane group, respectively. The XRD patterns of GG and GG‐PUF indicate their semicrystalline and amorphous nature, respectively. The field emission SEM of GG‐PUF exhibits high porosity compared to the smooth surface of GG due to the evolution of CO2 gas during the foaming reaction. The GG‐PUF was evaluated as an adsorbent for cationic dyes from wastewater. The preliminary adsorption studies showed maximum adsorption for malachite green with 93.54% removal at 40 °C and pH 6.0 in 60 min. The adsorption mechanism was studied by various nonlinear kinetic models, namely the pseudo‐first order, pseudo‐second order and Elovich, and nonlinear isotherm models, such as Langmuir, Freundlich and Temkin. The adsorption followed pseudo‐secondorder kinetics and a Langmuir isotherm with a maximum adsorption capacity of 156.44 mg g−1. The small value of the error function (χ2) and normalized standard deviation (Δq%) from nonlinear models indicated the better fitting of the data into nonlinear kinetics and isotherm models. Furthermore, GG‐PUF showed substantial degradability under simulated wastewater conditions at acidic and alkaline pH and reusability up to 10 adsorption–desorption cycles. Hence, GG‐PUF has tremendous potential as a sustainable, economical and environmentally friendly adsorbent for eliminating cationic dyes from wastewater. © 2024 Society of Chemical Industry.

Design, Synthesis and Bioactivity of Benzyl Propiolates with Broad-Spectrum Inhibition Activity on Phytopathogenic Fungi.

As part of our continuing research on propiolic acid derivatives, a series of benzyl propiolate derivatives and analogues were designed, synthesized, and investigated for inhibition activity in vitro and in vivo on phytopathogenic fungi, structure-activity relationship (SAR) and action mechanism. The results showed that most of the compounds had potent and broad-spectrum antifungal activity in vitro at 50 μg/mL. Among the compounds, 2-bromobenzyl propiolate (3h) displayed the highest comprehensive activity with total activity index (TAI) of 4.57 against all the eight test fungi followed by 3-fluorobenzyl propiolate (3c) (TAI = 4.53), superior to positive fungicides thiabendazole (TAI < 4.12) and/or azoxystrobin (TAI < 2.90). Relative to the other fungi, Fusarium solani and Fusarium graminearum revealed higher total susceptibility indexes (TSI) of 11.1 and 8.98, respectively, for all compounds. 3h and 3g (4-chlorobenzyl propiolate) gave the smallest EC50 values of 0.86 and 0.67 μg/mL against F. solani and F. graminearum, respectively, superior or comparable with thiabendazole and azoxystrobin. As a representative, 3h at 200 μg/mL displayed 100% protection on F. solani infections on potatoes over 7 days and high safety for plant growth. In antifungal mechanism, 3h was able to change mycelial morphology, destroy the structures of both hypha and cell membrane, increase the intracellular ROS level, decrease the intracellular mitochondrial membrane potential level, and change the permeability of the cell membrane. The SAR showed that ethynyl is a key group for the activity, and the presence of halogen atoms at the 2-site of the benzene ring can significantly improve the activity in most cases. Thus, benzyl propiolate can be considered a novel antifungal lead compound, while 3h can be considered a promising fungicide candidate to develop new agricultural fungicides.

Covalent Organic Frameworks for Boosting H2O2 Photosynthesis via the Synergy of Multiple Charge Transfer Channels and Polarized Field.

Covalent organic frameworks (COFs) serve as one of the most promising candidates for hydrogen peroxide (H2O2) photosynthesis, while attaining high-performance COFs remains a formidable challenge due to the insufficient separation of photogenerated charges. Here, through the rational design of bicarbazole-based COFs (Cz-COFs), we showcase the first achievement in piezo-photocatalytic synthesis of H2O2 using COFs. Noteworthily, the ethenyl group-modified Cz-COFs (COF-DH-Eth) demonstrates a record-high yield of H2O2 (9212 μmol g-1 h-1) from air and pure water through piezo-photocatalysis, which is ca. 2.5 times higher than that of pristine Cz-COFs without ethenyl groups (COF-DH-H) under identical condition and COF-DH-Eth without ultrasonic treatment. The H2O2 production rate originates from the synergistic effect between an ultrasonication-induced polarized electric field and the spatially separated multiple charge transfer channels, which significantly promote the utilization of photogenerated electrons by directional transfer from bicarbazole groups to the ethenyl group-modified benzene rings. Several Cz-COFs and bifluorenylidene-based COFs (COF-BFTB-H) with similar twisted monomers exhibit obvious piezoelectric performance for promoting H2O2 generation, signifying that organic ligands with a twistable structure play a crucial role in creating broken symmetry structures, thereby establishing piezoelectric properties in COFs.

Pressure-Engineered Through-Space Conjugation for Precise Control of Clusteroluminescence.

Clusteroluminogens (CLgens) represent an innovative class of nonconjugated luminophores that address the limitations of conventional π-conjugated molecules. Different from the through-bond conjugation mechanism in π-conjugated luminophores, through-space conjugation (TSC) plays dominant roles in CLgens. However, precisely controlling TSC to customize the optical properties of CLgens remains a significant challenge. This work proposes a novel strategy of high pressure to engineer TSC within tetraphenylalkanes (TPAs)-based CLgens at molecular level. High-pressure exploration enables accurate manipulation of clusteroluminescence and elucidates the intrinsic structure-property relationships involved. Upon initial compression, the predominant molecular distortions marked by increased interfacial angles between benzene rings diminish TSC, resulting in anomalous hypochromatic shift in emission. Subsequently, considerable structural contraction enhances TSC and suppresses molecular motion, resulting in a pronouncedly enhanced and bathochromic-shifted emission. Notably, a series of TPAs-based CLgens exhibit intense white-light emission upon pressure release, attributed to irreversible structural distortion and destruction. This study not only advances the understanding of CLgens, but also underscores the crucial structural factors for effective TSC control, paving the way for establishing new photophysical theories for aggregate science.

Pressure‐Engineered Through‐Space Conjugation for Precise Control of Clusteroluminescence

Clusteroluminogens (CLgens) represent an innovative class of nonconjugated luminophores that address the limitations of conventional π‐conjugated molecules. Different from the through‐bond conjugation mechanism in π‐conjugated luminophores, through‐space conjugation (TSC) plays dominant roles in CLgens. However, precisely controlling TSC to customize the optical properties of CLgens remains a significant challenge. This work proposes a novel strategy of high pressure to engineer TSC within tetraphenylalkanes (TPAs)‐based CLgens at molecular level. High‐pressure exploration enables accurate manipulation of clusteroluminescence and elucidates the intrinsic structure‐property relationships involved. Upon initial compression, the predominant molecular distortions marked by increased interfacial angles between benzene rings diminish TSC, resulting in anomalous hypochromatic shift in emission. Subsequently, considerable structural contraction enhances TSC and suppresses molecular motion, resulting in a pronouncedly enhanced and bathochromic‐shifted emission. Notably, a series of TPAs‐based CLgens exhibit intense white‐light emission upon pressure release, attributed to irreversible structural distortion and destruction. This study not only advances the understanding of CLgens, but also underscores the crucial structural factors for effective TSC control, paving the way for establishing new photophysical theories for aggregate science.