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[Display omitted] The targeted conversion of toxic nitroarenes to corresponding aminoarenes presents significant promise in simultaneously addressing environmental pollution concerns and producing value-added fine chemicals. In this study, we synthesize a 0D/2D ZnIn 2 S 4 homojunction (CH-ZnIn 2 S 4) by in situ growth of cubic ZnIn 2 S 4 (C-ZnIn 2 S 4) quantum dots onto the surface of ultrathin hexagonal ZnIn 2 S 4 (H-ZnIn 2 S 4) nanosheets for photocatalytic reduction of nitroarenes to aminoarenes using water as a hydrogen donor. The optimal performance of photocatalytic nitro reduction over the 0D/2D CH-ZnIn 2 S 4 homojunction reaches 96.1% within 20 min of visible light irradiation, which is 2.45 and 1.52 times than that of C-ZnIn 2 S 4 (39.3%) and H-ZnIn 2 S 4 (63.3%), respectively. The improved photocatalytic performance can be attributed to the formation of a step-type S-scheme homojunction, characterized by identity chemical composition and natural lattice matching. The configuration enables continuous band bending and a low energy barrier of charge transportation, benefiting the charge transfer across the interface while maximizing their redox capabilities. Furthermore, the 2D structure of H-ZnIn 2 S 4 nanosheets offers abundant surface sites to immobilize the 0D C-ZnIn 2 S 4 that provides ample exposed active sites with low overpotential for HER, thereby ensuring high hydrogenation reduction activity of nitroarenes. The study is expected to inspire further interest in the reasonable design of homojunction structures for efficient and sustainable photocatalytic redox reactions. [ABSTRACT FROM AUTHOR]

A one-step method to convert nitroarenes into aryl sulfones under operationally simple, transition-metal-free conditions is described. A range of nitroarenes were reacted with sodium sulfinates and caesium carbonate in N , N ′-dimethylpropyleneurea to afford aryl sulfones in up to 83% yield. [ABSTRACT FROM AUTHOR]

A novel TiO2/CoFe2O4/SiO2 magnetic nanocomposite was successfully synthesized using sol–gel and hydrothermal methods. This nanocomposite consists of highly dispersed CoFe2O4 and TiO2 nanoparticles on the surface of the SiO2 matrix. The synthesis process involved the utilization of activated carbon, which played a dual role as a support for depositing the CoFe2O4 and TiO2 nanoparticles and as a rigid pattern for producing the silica matrix that enmeshed the nanoparticles. To study the unique characteristics of the samples, a range of analytical techniques, such as FT‐IR, VSM, XRD, SEM, N2 adsorption–desorption analysis, BET and EDX were employed. We carried out a complete examination of the catalytic performance of the TiO2/CoFe2O4/SiO2 nanocomposite for the reduction of different substances, including methyl orange (MO), safranin O (SO), methylene blue (MB), rhodamine B (RhB), chromium (VI) ions, and nitroaromatic compounds such as 2‐nitrophenol (2‐NP), 4‐nitroaniline (4‐NA), 2‐nitroaniline (2‐NA), and 4‐nitrophenol (4‐NP). The findings of our study demonstrate the remarkable efficacy of the TiO2/CoFe2O4/SiO2 nanocomposite in efficiently reducing dyes, Cr (VI), and nitroaromatic compounds to their desired forms in environmentally friendly aqueous solutions. Notably, the nanocomposite stands out due to its simple synthesis process, effortless recyclability, and its convenient separation by a magnet. [ABSTRACT FROM AUTHOR]

The present research utilizes the simple "plug-and-play" strategy to effectively impart layered rare-earth hydroxides with remarkable sensitivity, selectivity, and rapid fluorescence sensing detection ability towards nitroaromatic compounds, employing the excited-state proton transfer fluorescence quenching mechanism. This opens new possibilities for the efficient and accurate detection of toxic and hazardous nitroaromatic compounds and effectively protecting environmental health and public safety. [Display omitted] Convenient, rapid, and accurate detection of nitroaromatic organic toxins and harmful substances is of great significance in research. In the present study, two-dimensional layered rare-earth hydroxides (LYH) were used as ion-exchange matrix materials, and the anionic fluorescent dye molecules (HPTS) were successfully introduced into the LYH structures in situ via a simple and effective "plug-and-play" strategy, which gave the compounds ultra-sensitive fluorescence sensing detection of nitrobenzene, p-nitrotoluene and p-nitrophenol (Fluorescence response time < 1 sec , and the LOD for nitrobenzene, p-nitrophenol and p-nitrotoluene reached an impressive 349 ppb, 22 ppb and 98 ppb, respectively). Combined with theoretical calculations, we elucidated in detail the fluorescence quenching response mechanism of the LYH-HPTS towards nitroaromatic. Additionally, we also constructed fluorescent paper sensor, which effectively transformed the LYH-HPTS from theoretical detection to device application. The LYH-HPTS material is not only simple to synthesize, cost-effective and stable, but also has the features of fast response, excellent sensitivity and selectivity, and good reproducibility, which provides a new approach for the rapid and accurate detection of nitroaromatic. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chemical pollutants, such as nitroaromatic compounds, have been a significant challenge in recent decades of human societies as they contribute to environmental pollution and pose serious health risks due to their high toxicity. One promising and green method to address this issue is the photocatalytic reduction of nitroaromatic compounds to their corresponding amino aromatic compounds. In this study, an rGO/CuBi2O4 nanocomposite was synthesized using the hydrothermal method, involving the simultaneous reduction of graphene oxide and the coupling of CuBi2O4 nanoparticles in its layers. The resulting heterogeneous structure was characterized using various techniques including FTIR, Raman, XPS, XRD, FESEM, TEM, EDAX, UV–Vis DRS, BET, PL spectroscopy, and EIS. Subsequently, the photocatalytic efficiency of the nanocomposite in reducing nitroaromatic compounds to the corresponding aromatic amines under visible light was evaluated. RESULTS: The results indicated that graphene oxide was effectively reduced and coupled with CuBi2O4 nanoparticles in the reduced graphene oxide sheets. The rGO/CuBi2O4 heterogeneous nanocomposite successfully reduced nitroaromatic compounds to the corresponding aromatic amines under visible light. Hydrazine monohydrate was used to supply the necessary hydrogen for the reaction. CONCLUSION: This study confirmed the high photocatalytic activity of the rGO/CuBi2O4 heterogeneous nanocomposite. Our nanocomposite was more effective than others, reported in similar studies, at reducing nitroaromatic compounds to the corresponding amino aromatic compounds. Additionally, it demonstrated high recycling and reuse properties, as there was no significant change in reaction conversion percentage and nanocomposite amount after 16 reuses. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

A straightforward method for the dehydrogenative alkylation of quinoxalin-2(1H)-ones with alkylbenzenes has been developed, facilitated by a photoexcited nitroarene. The reaction's success hinges on the dual role of the photoexcited nitroarene molecule, acting as both a hydrogen atom transfer (HAT) reagent and an oxidant. This technique is both atom-economical and cost-effective, due to the readily available nitroarene, which serves as the sole intermediary in the reaction process. [ABSTRACT FROM AUTHOR]

As the simplest nitroaromatic compound, nitrobenzene is an interesting model system to explore the rich photochemistry of nitroaromatic compounds. Previous investigations of nitrobenzene's photochemical dynamics have probed structural and electronic properties. These investigations paint, at times, a convoluted and sometimes contradictory description of the photochemical landscape. We investigate the ultrafast dynamics of nitrobenzene triggered by photoexcitation at 267 nm for the first time using a structural probe with femtosecond time resolution. Our probe complements previous measurements of nitrobenzene's electronic structure evolution and aids in determining the photochemical dynamics with less ambiguity. We employ megaelectronvolt ultrafast electron diffraction to follow nitrobenzene's structural evolution within the first 5 ps after photoexcitation. We observe ground state recovery within 160 ± 60 fs through nonadiabatic dynamics. Based on comparisons of the experimental signal with molecular dynamics simulations, we exclude a significant population of the triplet manifold. Furthermore, we do not observe fragmentation of nitrobenzene within the investigated time window, which indicates that previously observed photofragmentation reactions take place in the vibrationally 'hot' ground state on timescales considerably beyond 5 ps. [ABSTRACT FROM AUTHOR]

In this study, ternary magnetic rod-like nanocomposites of Bi2O2CO3/MIL-88B(Fe)/CoFe2O4 were successfully synthesized using a straightforward hydrothermal method. The process involved the integration of different amounts of bismuth subcarbonate (Bi2O2CO3) nanoparticles with an iron-based rod-like metal–organic framework (MIL-88B(Fe)) and magnetic CoFe2O4 nanoparticles. A range of analytical techniques, including Fourier transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), vibration sample magnetometry (VSM), Brunauer–Emmett–Teller analysis, and zeta potential measurements were employed to examine the structural characteristics, composition, crystallinity, morphology, magnetic properties, surface area, and surface charge of the resulting nanocomposite. The nanocomposite demonstrated significant catalytic activity in the reduction of nitroaromatic compounds specifically 4-nitrophenol (4-NP), 2-nitrophenol (2-NP), 4-nitroaniline (4-NA), and 2-nitroaniline (2-NA) in aqueous solutions, utilizing sodium borohydride (NaBH4) as a reducing agent at room temperature. Notably, rapid reduction rates were observed under the selected conditions, with 4-NP being reduced in 14 minutes (kapp = 0.162 min−1), 2-NP in 25 minutes (kapp = 0.105 min−1), 4-NA in 8 minutes (kapp = 0.405 min−1), and 2-NA in 10 minutes (kapp = 0.272 min−1). Additionally, the Bi2O2CO3/MIL-88B(Fe)/CoFe2O4 catalyst could be readily separated from the reaction mixture using an external magnetic field and was found to be recyclable up to four times without a notable decrease in catalytic performance. Even after four uses, the catalyst retained its stability, original structure, crystalline nature, and morphology. [ABSTRACT FROM AUTHOR]

The detection of explosive materials, particularly nitroaromatic compounds such as 2,4,6‐trinitrotoluene (TNT), is critical for public safety and national security. Existing detection methods often require complex instrumentation, limiting their applicability for real‐time or in‐field use. Fluorescent sensors, which offer rapid and sensitive detection through fluorescence quenching, present a promising alternative. This study evaluates the performance of two pentiptycene‐based polymers, P‐1 and P‐2, in detecting explosive vapors, with a specific focus on their behavior under high‐humidity conditions. P‐2, modified with triethylene glycol groups, demonstrated significantly increased hydrophilicity compared to the commonly studied P‐1, as confirmed by contact angle measurements. Spectroscopic analysis revealed a blue shift in P‐2's UV–Vis absorption and photoluminescence spectra, indicating electronic property changes due to structural modifications. The enhanced hydrophilicity of P‐2 enabled it to maintain stable sensing performance under moist conditions, showing less than a 10% reduction in sensitivity, compared to the 20% decrease observed in P‐1. This superior moisture resistance suggests that P‐2 is a more robust and practical sensor for explosive detection in environments with variable humidity levels. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) as an efficient and convenient sensing material for environmental pollutants have attracted widespread attention in recent years. Here in, we synthesized a series of lanthanide co‐doping MOFs, EuxTb1‐x‐MOFs (x=0, 0.005, 0.00667, 0.01, 0.02 and 1) under solvothermal conditions. The luminescence colors can be adjusted by changing metal molar mass ratios and altering excitation wavelength. Fortunately, a near white‐light‐emitting material Eu0.01Tb0.99‐MOF was obtained under the excitation at 350 nm, whose CIE coordinates of (0.3444, 0.3409) are very close to standard white light coordinates (0.3333, 0.3333). We further studied the fluorescence sensing performances of Eu‐MOF, Tb‐MOF and Eu0.01Tb0.99‐MOF towards NACs. The results indicate that all MOFs can selectively detect 4‐nitroaniline, 4‐nitrophenol and 2‐nitrophenol with good sensitivity and recyclability. [ABSTRACT FROM AUTHOR]

Atmospheric aerosols in megacities impact air quality and public health. However, limited information exists on the detailed molecular composition of organic aerosols in urban areas. This study characterized the molecular composition of organic aerosols (OA) in Shanghai, Beijing and Guangzhou, China, during summer and winter of 2021. Liquid chromatography-orbitrap mass spectrometry detected 4536−5560 and 2067− 3489 organic molecular formulas in positive (ESI+) and negative (ESI−) electrospray ionization modes, respectively. CHO and CHON compounds accounted for over 80% and 60% of total abundance in ESI+ and ESI−, respectively, suggesting their significant contribution to urban OA. The number and abundance percentages of CHO showed obvious seasonal variation, with more CHO in summer than in winter, while CHON exhibited the opposite trend in Beijing and Shanghai. Compared with winter, a lower unsaturation degree, reduced aromaticity, and higher oxidation state of OA in summer were observed in Beijing and Shanghai, while these seasonal variations were not as obvious in Guangzhou, likely due to regional climate differences. The number percentage of common compounds between Beijing and Shanghai was higher than that between Guangzhou and Beijing (or Shanghai). Nitroaromatic compounds were more prevalent in winter than in summer. Further analysis of atmospheric formation relevance and precursor-product pairs suggested that CHON compounds are derived from the oxidization or hydrolyzation processes, revealing potential chemical transformations of these aerosols. This study characterized the chemical makeup of organic aerosols, providing insight into their sources and characteristics in these cities. [ABSTRACT FROM AUTHOR]

To better understand the transport behavior of nitroaromatic compounds (NACs) in soils, it is significant to systematically evaluate the factors influencing NACs adsorption to smectite clays and thoroughly elucidate major interactive mechanisms. The binding affinity of smectite clays for NACs was clearly influenced by both interlayer cations and surface charge density of smectite. When saturated with K+, Cs+ or NH4+, smectite clays exhibited higher binding abilities for 2,4-dinitrobenzene (2,4-DNT), as compared to those saturated with Na+, Ca2+ or Al3+. A negative correlation existed between the charge density of K+-smectite and its binding ability for 2,4-DNT (not including the smectite with the lowest charge density). As pH decreased, the main interaction between dissociable NACs and smectite clays shifted from the electrostatic repulsion to the specific adsorption, resulting in higher adsorption at lower pH. With higher solution ionic strength, the quasi-crystal structure of smectite formed mainly due to the better-ordered lamellae, which led to the stronger sorption potential of the smectites for NACs. The adsorption of dimethylnitrobenzenes differed to some extent among the isomers, attributed to the steric hindrance related to the position of nitro and methyl groups. The adsorption of NACs was promoted slightly due to substitution of -CH3 for -H and considerably substitution of -NO2 for -CH3. The presence of cation binders (crown ether 18c6e and 15c5e) evidently weakened the adsorption of 2,4-DNT by K+- and NH4+-smectite. Macroscopic adsorption results, along with electronic property of NAC molecules (atomic charge and electrostatic potential), demonstrated that the electrostatic interaction between smectite cations and nitro of NACs was the predominant force in mediating their adsorption. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV–vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO's absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10–4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges. [ABSTRACT FROM AUTHOR]

A novel 3D luminescent metal--organic framework (MOF) named as [Eu(HPyzdc)(NITA)(H2O)]n (Cj-3) has been synthesized with the dual ligand approach involving nitro functionalised isophthalic acid (H2NITA) and pyrazine based dicarboxylic acid (2,3-H2Pyzdc) via a solvothermal method. Analysis of its structure reveals that Cj-3 is composed of tetranuclear secondary building units (SBUs) with uncoordinated carbonyl and hydroxyl groups, which serve as potential recognition sites for interacting with analytes. Cj-3 shows unique luminescence features and is projected for its potential in detecting metal ions (Fe3+ and Cr3+) as well as picric acid (PA) and amine-substituted NACs (nitroanaline). The luminescence experiments show distinct luminescence quenching and enhancement effects, particularly towards nitroaniline (p-NA and o-NA), picric acid (PA), Hg2+ and Cr3+ ions. Cj-3 displays exceptional selectivity and sensitivity towards Cr3+, Hg2+, and PA, along with rapid response times and excellent recyclability. Competitive absorption of excitation energy and electron transfer are probable mechanisms for sensing nitroaromatic compounds, while host--guest interactions are responsible for detecting metal ions. Additionally, visual luminescent test papers based on Cj-3 have been developed which can selectively detect NACs and metal ions. Moreover, Cj-3 can generate latent fingerprints on diverse surfaces, with intricate details observable upon magnification. These findings suggest significant potential for applying Cj-3 as a luminescent MOF in security applications. [ABSTRACT FROM AUTHOR]

Mononuclear Zn(II) compounds, [Zn(L1)](ClO4)2 (1) and [Zn(L2)](ClO4)2 (2), embedded with ligands, L1=N1‐(pyridin‐2‐ylmethyl)‐N2‐(2‐((pyridin‐2‐ylmethyl)amino)ethyl)ethane‐1,2‐diamine and L2=N1‐(pyridin‐2‐ylmethyl)‐N3‐(3‐((pyridin‐2‐ylmethyl)amino)propyl)propane‐1,3‐diamine are synthesized. Compound 1 is revisited, and structure‐function relation is compared with new compound 2. Single crystal X‐ray analysis revealed that compound 1 crystallizes in the tetragonal non‐centrosymmetric P41 space group while 2 crystallizes in a centrosymmetric monoclinic space group P21/c. The asymmetric unit consists of a crystallographically independent [Zn(L1)]2+cation in 1 while [Zn(L2)]2+cation in 2 and two unique perchlorate anions in both. IR spectra of 1 and 2 confirmed the vibrations due to organic ligands and tetrahedral perchlorates. PXRD confirmed the phase purity of powdered samples compared with theoretical PXRD patterns obtained from single‐crystal X‐ray diffraction data. NMR and ESI‐MS data suggested the phase purity and stability of compounds 1 and 2 in solution. Photoluminescence properties of compounds 1 and 2 have been investigated, considering their application in sensing explosive nitroaromatic compounds. Our results suggest that compound 1 is very selective in the chemical sensing of trinitrophenol (TNP) and dinitrophenol (DNP) in an aqueous medium compared to the reactivity of compound 2. The existence of spectral overlap in the absorption spectra of 2,4‐dinitrophenol (DNP) and 2,4,6‐trinitrophenol (TNP) with the emission spectrum of 1 or 2 indicates the operation of the resonance electron transfer (RET) mechanism. [ABSTRACT FROM AUTHOR]

A combination of N,N',N"-tris(3-pyridyl)-1,3,5-benzenetricarboxamide (L1) and p-chlorobenzoic acid (HL2) with Zn(NO3)2·6H2O resulted in the formation of a dinuclear metallacycle [ZnL1(L2)2(DMF)2]2 (1(DMF)4). In 1(DMF)4, the Zn(II) centre adopts a square pyramidal geometry, while one of the pyridyl N out of the three pyridyl groups in L1 remained uncoordinated. Solvated DMF molecules are present in 1(DMF)4. The structural and chemical nature of 1(DMF)4 is effective for it to act as a potential fluorescent probe for the detection of nitroaromatic compounds. It is observed that the probe, 1(DMF)4, could selectively detect picric acid (PA) among various aromatic compounds in solution (DMSO), while the solid state (contact mode) detection showed a positive sensing response for the nitrophenols (PA: 87% quenching efficiency, 2,4-dinitrophenol (2,4-DNP): 57% quenching efficiency and 4-nitrophenol (4-NP): 40% quenching efficiency). The limit of detection (LOD) of PA by the probe in DMSO was found to be 6.8 × 10-11 M while the LOD in contact mode detection was estimated to be 0.49 ng cm-2. The mechanism of selective detection of PA by 1(DMF)4 in DMSO was analyzed through photophysical studies, 1H-NMR experiments and also by density functional theory (DFT) calculations. The effective overlap of the absorption spectrum of 1(DMF)4 and emission spectrum of PA in DMSO suggests that the Förster resonance energy transfer (FRET) is responsible for quenching phenomena in DMSO. The DFT calculations and molecular docking studies showed the adduct formation due to the favorable interactions between 1(DMF)4 and PA in DMSO, while negligible interactions were observed between 1(DMF)4 with other aromatic compounds. The experimental and DFT studies showed that the efficient sensing ability of PA by 1(DMF)4 in the solid-state was due to photoelectron transfer (PET) and FRET phenomena described herein. [ABSTRACT FROM AUTHOR]

N,S‐Doped highly ordered mesoporous carbon (N,S‐doped OMC) material was constructed by the nanocasting methodology using egg yolk with a high content of amino acids as a carbon precursor and SBA‐15 as a hard template, followed by carbonization at 500 °C under an N2 atmosphere, and then aqueous alkaline‐induced removal of the silica moiety of the SBA‐15 template. Prepared N,S‐doped OMC material efficiently catalyzed the formylation of various substituted anilines using DMF as a formylating agent in water, to afford N‐formylaniline derivatives in high to excellent yields. Also, as‐prepared N,S‐doped OMC was used to immobilize and stabilize the Pd nanoparticles in order to synthesize Pd@OMC material, which was used as an efficient catalyst for the hydrogenation of nitroaromatic compounds to the corresponding aniline derivatives. Nitroaromatic compounds are considered to be highly toxic water contaminant compounds, and their removal from wastewater by the hydrogenation is an interesting method. Furthermore, Pd@OMC catalyzed one‐pot tandem hydrogenation of nitrobenzene/formylation reactions was investigated, which gave corresponding N‐formyl aniline in high yield. Synthesized OMC and Pd@OMC were characterized using X‐ray diffraction (XRD), Brunauer‐Emmett‐Teller (BET), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), and transmission electron microscopy (TEM) analysis. [ABSTRACT FROM AUTHOR]

Nitrophenols (e. g., para nitrophenol), although they have beneficial properties, their residuals are injurious to the environment owing to their high lethal potential for many categories of nature (e. g. animals, humans, plants, etc.), which require their monitoring. In this paper, a new Clay/green reduced graphene oxide composite (Clay/rGO) was efficaciously synthesized and utilized as an excellent modifier for carbon paste electrode (CPE) for the electro‐analytical determination of paranitrophenol (PNØ). The electrochemical futures and reduction of PNØ at the surface of the as‐prepared Clay/rGO˧CPE have been executed using DPV differential pulse voltammetry (DPV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The use of the EIS provided that the Clay/rGO˧CPE facilitate the electron exchange process. By using the DPV technique in phosphate buffer (PB) under biological pH (7) (PB_7) the prepared monitor exhibited an excellent linearity relationship in the concentration ranges from 1.0 to 1000.0 μM with a detection limit (DL=3×σ/P) of 0.16 μM and a quantification limit of (QL=10×σ/P) of 0.54 μM. The Clay/rGO˧CPE offered high selectivity and a satisfactory concert in the electroanalytical sensing of PNØ in wastewater sample. [ABSTRACT FROM AUTHOR]

A novel 3D luminescent metal–organic framework (MOF) denoted as [Eu(BTA)0.5(H2BTA)0.5(H2O)]n (Cj-2) has been constructed from a π-conjugated ligand with a tetracarboxylate group, 1,2,4,5-benzenetetracarboxylic acid (BTA), via solvothermal synthesis. Structural analysis reveals that the Cj-2 framework is composed of tetranuclear secondary building units (SBUs) containing uncoordinated carbonyl groups which provide feasible recognition sites to interact with analytes. Cj-2 shows a trinodal (4,6,10)-connected 3D topological network consisting of tetranuclear SBUs. Cj-2 displays outstanding potential as a luminescent sensor for detecting o-NP and Cd2+ in DMF suspension, with remarkable sensitivity and selectivity through the luminescence quenching effect. Cj-2 displays excellent luminescence quenching behaviour in the presence of other competing interfering analytes and can be recycled at least four times for sensing o-NP and Cd2+. For Cd2+ ions, it is the host–guest interactions and for the nitroaromatic compounds, it is the competitive absorption of excitation energy and the electron transfer mechanism that are the probable mechanisms for such sensing processes. Moreover, visual fluorescent test papers based on Cj-2 were assembled and employed to selectively detect nitroaromatic compounds and metal ions. Based on the aforementioned results, Cj-2 can be considered as a potential luminescence sensor for detecting Cd2+ and o-NP. [ABSTRACT FROM AUTHOR]

Picric acid is known as one of the most dangerous explosive materials and it has become one of the main pollutants in soil and, inter alia, groundwater. To date, many organic or inorganic probes have been reported to detect picric acid, especially in organic solvent systems. Nonetheless, the detection and adsorption of trace (sub-ppm or ppb level) picric acid in aqueous media remain challenging. Herein, we describe the facile synthesis of a tetraphenylethylene-based superphane cage via [6 + 2] condensation of dialdehyde and hexakis-amine, followed by a NaBH4–mediated reduction. This purely covalent organic cage was found able to show aggregation enhanced emission in a mixture of tetrahydrofuran and water (1:9, v/v), which can be utilised as a probe for detection of picric acid with ultrahigh sensitivity (as low as 0.9 ppb) and selectivity (against other tested nitroaromatic compounds). More importantly, this new superphane cage can serve as a new nonporous amorphous superadsorbent (NAS) material for adsorption of picric acid with an exceptional maximum uptake capability of 454 mg g−1. It also proved able to eliminate trace picric acid from aqueous media with up to 99% removal efficiency, meeting the discharge standard (<1.0 ppb). As such, we believe that this study offers new insight into the design and synthesis of NAS-based advanced materials for sensitive and selective detection and adsorption of trace pollutants from complex aqueous wastes. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds (NACs) stand out as pervasive organic pollutants, prompting an imperative need to investigate their hazardous effects. Computational chemistry methods play a crucial role in this exploration, offering a safer and more time-efficient approach, mandated by various legislations. In this study, our focus lay on the development of transparent, interpretable, reproducible, and publicly available methodologies aimed at deriving quantitative structure–activity relationship models and testing them by modelling the mutagenicity of NACs against the Salmonella typhimurium TA100 strain. Descriptors were selected from Mordred and RDKit molecular descriptors, along with several quantum chemistry descriptors. For that purpose, the genetic algorithm (GA), as the most widely used method in the literature, and three alternative algorithms (Boruta, Featurewiz, and ForwardSelector) combined with the forward stepwise selection technique were used. The construction of models utilized the multiple linear regression method, with subsequent scrutiny of fitting and predictive performance, reliability, and robustness through various statistical validation criteria. The models were ranked by the Multi-Criteria Decision Making procedure. Findings have revealed that the proposed methodology for descriptor selection outperforms GA, with Featurewiz showing a slight advantage over Boruta and ForwardSelector. These constructed models can serve as valuable tools for the quick and reliable prediction of NACs mutagenicity. [ABSTRACT FROM AUTHOR]

A novel microwave‐assisted intercalation (MAI) strategy is proposed for fast and efficient intercalation of layered MXene to prepare large‐size single‐layer MXene. After LiF‐HCl etching of Ti3AlC2, the as‐prepared multi‐layer Ti3C2Tx (M‐T) are intercalated with Li3AlF6 as an intercalator and ethylene glycol (EG) as a solvent under microwave irradiation for 5 min. Furthermore, the dispersed high‐quality large‐sized single‐layer Ti3C2Tx (S‐T) nanosheets with a thickness of 1.66 nm and a large lateral size over 20 µm are achieved with a yield of over 60% after a further ultrasonic delamination followed by electrostatic precipitation, acid washing, and calcination. In addition, Pd/S‐T composite catalyst, which is constructed with Pd nanoparticles supported on the as‐prepared S‐T nanosheets, exhibits an excellent performance for rapid and efficient selective hydrogenation of nitroarenes with H2 under a mild condition. At room temperature, full conversion of nitrobenzene and 100% aniline selectivity are achieved over Pd/S‐T catalyst in 20 min with 0.5 MPa of H2 pressure. This work provides a novel method for facile, fast, and large‐scale preparation of single‐layer MXene and develops a new approach for constructing efficient nanocatalytic systems. [ABSTRACT FROM AUTHOR]

Leishmania infantum is the vector-borne trypanosomatid parasite causing visceral leishmaniasis in the Mediterranean basin. This neglected tropical disease is treated with a limited number of obsolete drugs that are not exempt from adverse effects and whose overuse has promoted the emergence of resistant pathogens. In the search for novel antitrypanosomatid molecules that help overcome these drawbacks, drug repurposing has emerged as a good strategy. Nitroaromatic compounds have been found in drug discovery campaigns as promising antileishmanial molecules. Fexinidazole (recently introduced for the treatment of stages 1 and 2 of African trypanosomiasis), and pretomanid, which share the nitroimidazole nitroaromatic structure, have provided antileishmanial activity in different studies. In this work, we have tested the in vitro efficacy of these two nitroimidazoles to validate our 384-well high-throughput screening (HTS) platform consisting of L. infantum parasites emitting the near-infrared fluorescent protein (iRFP) as a biomarker of cell viability. These molecules showed good efficacy in both axenic and intramacrophage amastigotes and were poorly cytotoxic in RAW 264.7 and HepG2 cultures. Fexinidazole and pretomanid induced the production of ROS in axenic amastigotes but were not able to inhibit trypanothione reductase (TryR), thus suggesting that these compounds may target thiol metabolism through a different mechanism of action. [ABSTRACT FROM AUTHOR]

.Reductive C−N bond generation strategies of nitroarenes to form N‐arylformamide and azole derivatives were developed under the influences of magnetically separable Pd@rGO‐CuFe2O4 nanoparticle‐catalyzed reaction conditions. These reactions proceed at a very low catalyst loading in H2O as the solvent, which leads to a higher percentage of yields (up to 96 %) of the products. The catalyst is recovered from the reaction medium by using an external magnet and recycled for four consecutive reaction cycles with a less amounts of leaching. [ABSTRACT FROM AUTHOR]

Nanomaterials have revolutionized various scientific and industrial domains due to their exceptional properties and diverse applications. Yet, challenges persist in achieving their controlled synthesis, stability, and recyclability, especially in catalysis. Organoselenium compounds are emerging as promising agents for the stabilization of nanomaterials, with high prospects for catalytic applications. This article covers the recent strides made in harnessing the potential of organoselenium compounds to stabilize diverse nanomaterials with applications in catalysis. Specifically, it delves into their effectiveness in Suzuki‐Miyaura cross‐coupling, C−O coupling, Sonogashira coupling, reduction of nitroarenes, synthesis of primary amides (in aqueous medium), and offers a comprehensive overview of this evolving field. [ABSTRACT FROM AUTHOR]

The production of nitroaromatic compounds has not only agravated from some decades but their accidental or intentional release into the nearby environment, causes serious health problems. Lab-scale horizontal-subsurface-down-flow-constructed-wetland (HSDF-CW) was developed and planted with reeds to treat 2,4,6-Tri-nitro-toluene (TNT) contaminated soil collected from the site of industrial complex and was subjected to bioremediation, where domestic wastewater and TNT degrading bacterial strains were added as co-substrates for effective removal of nitro-aromatic compounds. Results showed that 80.1%, 60.08%, 85.7% &67.9% removal of COD, Total-Nitrogen, nitrate and sulphate respectively was attained through bioremediation, bio-stimulation (91%, 85.9%, 94% &80.01%) and bio-augmentation (90.5%, 90.9%, 95% & 91%)respectively after thirty days of incubation.FTIR results indicated the biotransformation of nitro-aromatic compounds into different intermediates.Moreover, phytotoxicity results suggested that treated-water had no toxic effect on seed germinations and could be used for irrigation. Thus,assisted bioremediation through CW proved to be an excellent alternate for in-situ treatment of nitro-aromatic-compounds. [ABSTRACT FROM AUTHOR]

The reactivity of dimethylamine borane (DMAB) towards amines and nitroarenes was investigated in the presence of the CO2 and Pd/PVP (PVP=polyvinylpyrrolidone) nanocatalyst. The formation of borane formate, Me2NH.BH2(OCHO), by the insertion of CO2 into the B−H bond was evidenced by NMR. The reaction of DMAB with CO2 also produced a second product, DMF, formed via self‐formylation. In the presence of aromatic or aliphatic amines corresponding N‐formamides were formed efficiently. Under the same conditions nitroarenes were hydrogenated to anilines or to azoxyarenes in the absence of CO2. In both reactions very high TOF values, up to 30 min−1, were obtained. Applying a higher excess of DMAB enabled the transformation of nitroarenes to N‐formamides. The Pd/PVP catalyst was used in 7 consecutive cycles of N‐methylaniline formylation with excellent selectivity and a total TON equal to 4700. [ABSTRACT FROM AUTHOR]

Regioselective distal C−H functionalization of nitroarenes by overriding proximal C−H activation has remained an unsolved challenge. Herein, we present a palladium-catalyzed meta-C−H alkenylation of nitroarene substrate, achieved through leveraging the non-covalent hydrogen bonding interactions. Urea-based templates comprising an elongated biphenyl linker designed in such a way that it interacts with nitro group via strong hydrogen bonding interaction, while a cyano based directing group is attached along the template to coordinate with the palladium center, thereby facilitating the activation of the remote meta-C−H bond of nitrobenzene. Computational mechanistic investigation and the analysis of non-covalent interaction deciphers the crucial role of H-bonding in regulating the regioselectivity. Regioselective distal C-H functionalization of nitroarenes by overriding proximal C-H activation has remained an unsolved challenge. Herein, the authors present a palladium-catalyzed meta-C-H alkenylation of nitroarene substrate, achieved through leveraging the noncovalent hydrogen bonding interactions. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds (NACs) cause severe hazardous impacts on human health as well as on the environment. Therefore, there is dire need to develop a robust material to reduce the toxicity of these organic pollutants. In this regard, our group developed a series of porous MOF materials viz., Pdx@IRMOF‐9 (x=2 %, 5 % and 10 %) by loading different concentration of Pd(II) on IRMOF‐9 and explored them towards reduction of different nitroaromatic compounds. Pd10%@IRMOF‐9showed ~30 % greater efficiency for the reduction of 4‐NP as compared to Pd2%@IRMOF‐9. Pd10%@IRMOF‐9showed excellent reduction ability (>85 %) towards 4‐NP, 2‐NP, 2‐NA, 3‐NA and 2,4‐DNPH. The kinetic studies indicates that the reduction follows the pseudo‐first‐order kinetics. Moreover, the rate constant value for reduction of 3‐NA was ~9 times higher than that of 2‐NP. Based on the kinetic parameters, the t1/2 values for all the nitroaromatics have been calculated. The kinetic parameters, Km and Vmax have been calculated from double reciprocal Lineweaver‐Burk plot and found to be 65.984 μM and 116×10−6 Mmin−1 respectively. Pd10%@IRMOF‐9showed excellent recyclability towards the reduction of 4‐NP for few consecutive cycles without any remarkable loss in its activity. Thus, highly efficient, porous and robust material for the reduction of nitroaromatic compounds in aqueous media have been demonstrated. [ABSTRACT FROM AUTHOR]

This study presents an electrochemical sensor for sensitive detection of nitroaromatic compounds using a three‐dimensional (3D) porous graphene with polyoxypropylene supported reduced graphene oxide (PEA‐RGO) and embedded β‐cyclodextrins (β‐CD). First, PEA‐RGO was synthesized by the condensation reaction between graphene oxide (GO) and amino‐terminated polyoxypropylene (PEA), followed by hydrazine hydrate reduction. Then, β‐CD was embedded into the porous of the above 3D graphene to obtain PEA‐RGO/β‐CD nanohybrid. Various characterization techniques, such as microscopy imaging, infrared spectrometry, thermal analysis and electrochemical measurements, were employed to confirm the successful synthesis and unique 3D architecture structure of PEA‐RGO/β‐CD. Afterwards, the glassy carbon electrode (GCE) was modified by PEA‐RGO/β‐CD, and its electrochemical detection performances were investigated for detecting nitroaromatic compounds, including nitrobenzene (NB), 2‐nitroaniline (2‐NA), 2‐chloronitrobenzene (2‐NCB), and 2‐nitrophenol (2‐NP). The results of electrochemical measurements exhibited relative higher sensitivities (1.88 μA/μM/cm2 for NB, 2.13 μA/μM/cm2 for 2‐NA, 2.35 μA/μM/cm2 for 2‐NP, 0.83 μA/μM/cm2 for 2‐NCB, respectively) and lower limits of detection (LOD) (39.4 nM for NB, 44.6 nM for 2‐NA, 75.6 nM for 2‐NP, 69.6 nM for 2‐NCB, respectively). Additionally, the proposed sensor was also applied in detection in real samples with recovery range of 88.13%–109.52 %. The enhanced detecting performances can be attributed to the synergistic effect of the high conductivity from RGO, recognition capabilities from β‐CD, and excellent properties from 3D structure. The present work would provide a robust tool for environmental monitoring and the detection of nitroaromatic pollutants. [ABSTRACT FROM AUTHOR]

Development of efficient and stable non‐noble metal catalysts applied to the catalytic transfer hydrogenation of nitroarenes under mild conditions is still challenging. Herein, we report magnetically recyclable catalysts prepared via simple two‐stage pyrolysis of Co‐MOF‐74 and melamine composites. The optimized catalyst Co@C/CNTs‐10‐700 shows excellent conversion and selectivity towards transfer hydrogenation of nitroarenes with different hydrogen donors. Its excellent stability against formic acid corrosion makes it can be used in a wide range. The excellent catalytic performance can be ascribed to the synergistic effect between carbon nanotubes and Co nanoparticles. Furthermore, the catalyst was easily recycled owing to its magnetism and reused up to ten consecutive cycles without significant loss of activity, indicating that the excellent catalytic stability holds great promise in fields of industrial application. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of functionalized nitroarenes to anilines employed with heterogeneous catalysts is a significant process and widely applied in chemical industry. However, designing high‐performance catalysts for these processes remains challenging. Recently, notable advancements have been achieved in synthesis methodologies, characterization techniques, and theoretical calculations, offering opportunities to gain insights into mechanisms. This review summarizes the recent progress in understanding the mechanistic aspects of selective hydrogenation catalysis for functionalized nitroarenes. We initiate by delving into the structure‐performance relationship, with the aim of providing a comprehensive understanding of mechanistic and kinetic details in the selective hydrogenation of functionalized nitroarenes. Subsequently, we introduce various strategies for designing high‐performance catalysts, categorizing them into three key aspects: isolating active sites, synergizing active sites and regulating local environments of active sites. Finally, we conclude with a concise overview of the current state of this field and provide a forward‐looking perspective for future studies, emphasizing the high‐performance design and manipulation of catalysts to achieve precise control over selectivity towards target products. [ABSTRACT FROM AUTHOR]

Eugenol, the major constituent of clove oil, has been explored as an essential natural ingredient for ages owing to its versatile pharmacological properties. However, to date, the coordination chemistry of eugenol derivatives has not been much explored. In the present work, an eugenol-based Schiff base ligand (HL) was synthesized and structurally confirmed through ESI-MS, NMR, and FT-IR spectroscopy studies. Consequently, the N,O-donor chelating ligand HL was coordinated with Cd2+, in the presence of bridging pseudohalides (thiocyanate, SCN−, and dicyanamide, N(CN)2−) to synthesize two luminescent coordination polymers (CPs 1 and 2): [Cd2(L)2(X)2]n (where HL = 4-allyl-2-(((2-(benzylamino)ethyl) imino)methyl)-6-methoxyphenol and Xs are bridging pseudohalides, i.e., SCN− and N(CN)2−) on a Cd-eugenol scaffold. The CPs depicted structural diversity, bulk-phase purity, thermal stability, and the presence of interlayer supramolecular C–H⋯π interactions together with C–H⋯S (for CP 1) and C–H⋯N (for CP 2) interactions. The CPs further exemplified themselves as selective and sensitive 'turn-off' probes towards trinitrophenol (TNP) (quenching efficiency: 82.02% and 83.86% for 1 and 2) among a pool of hazardous nitroaromatic compounds (NACs). Accordingly, 1 and 2 exhibited an ultralow limit of detection (LOD) of 0.29 and 0.15 μM, with high quenching constants (KSV) of 5.91 × 104 and 17.60 × 104 M−1, respectively. In addition, TNP sensing events were evidenced to be recyclable and exhibited fast response (∼31 s, 1, and ∼40 s, 2), which increased its real-world viability. Vapor phase TNP sensing was also accomplished upon drop-casted CP films. Experimental investigations and theoretical DFT study confirmed the cooperative occurrence of RET-IFE-PET-collisional quenching and non-covalent π⋯π stacking as key factors involved in the TNP sensing performance. The competency of 1 and 2 in the detection of TNP from several complex environmental matrices (CEMs), viz. matchstick powder, river and sewage water, and soil specimens, was also established with good recovery (∼66–86% and ∼68–93% for 1 and 2, respectively) and high KSV values (3.90–11.39 × 104 and 6.17–18.79 × 104 M−1 for 1 and 2, respectively). [ABSTRACT FROM AUTHOR]

The nanoconfinement approach for constructing ultra‐small nanoparticles has been effectively utilized in the development of non‐precious metal catalysts. Herein, the catalyst precursor was prepared by host‐guest assembly method, using PCN‐222 as the host and 1,1′‐bis(diphenylphosphino) ferrocene (DPPF) as the guest. After calcination, the sub‐2 nm iron oxide nanoparticles within a phosphorus‐nitrogen co‐doped carbon matrix (Fe3O4@P/N‐CDCM) was obtained. Benefiting from the nanoconfinement effect, the sub‐2 nm Fe3O4 nanoparticles were uniformly dispersed on the P/N‐CDCM matrix. As a representative application, Fe3O4@P/N‐CDCM‐600 showed remarkable catalytic activity in the reduction of various nitroaromatic compounds. Under ambient conditions, the efficient reduction of nitro compounds in aqueous solution led to excellent conversion rates (96–99 %) and selectivity (99 %) within 45 minutes. Additionally, the catalyst maintained high efficiency over 5 cycles without experiencing a noticeable decrease in activity. This work provides an innovative and cost‐effective strategy for fabricating highly dispersed non‐precious metal nanoparticles. [ABSTRACT FROM AUTHOR]

2,4-Dinitrotoluene (2,4-DNT) is a broadly applied nitroaromatic compound with multiple applications, and its simple production has resulted in its extensive utilization in producing explosives, dyes, and rubber. This substance is hazardous and induces genetic mutations in humans, fish, and microorganisms. Thus, this research was done to assess the effectiveness of the three-dimensional electro-Fenton (3D/EF) process employing magnetic activated carbon particle electrodes (GAC/Fe3O4) in eliminating 2,4-dinitrotoluene from water-based solutions. In this experimental investigation, Fe3O4 nanoparticles were created using the chemical co-precipitation technique. The G/β-PbO2 anode was fabricated by electrochemically depositing PbO2 layers on graphite sheets. G/β-PbO2 and stainless steel were utilized as the anode and cathode, respectively. The structure, particle size, and properties of the GAC/Fe3O4 nanocomposite were analyzed using FESEM, XRD, and EDX. The morphology of the G/β-PbO2 electrode was also examined using SEM. The Taguchi experimental design method was employed to identify the optimal conditions. The outcomes demonstrated that higher reaction time and current density, as well as lower pH and pollutant concentration, resulted in improved 3D/EF efficiency. Accordingly, the optimum values of parmeters were identified to be a concentration of 2,4-DNT = 50 mg/L, pH = 3, electrolysis time = 100 min, and current density = 8 mA/cm2. With these parameters, the degradation efficiency of 2,4-DNT through the examined system was 98.42 %, alongside removal efficiencies of 84.69 % for COD and 79.67 % for TOC. Additionally, the results indicated an increase in the average oxidation state (AOS) (from 1.27 to 1.95) and carbon oxidation state (COS) (from 1.27 to 2.75) in the 3D/EF process, along with a decrease in the COD/TOC ratio (from 1.81 to 1.36), indicating the effectiveness of the 3D/EF system in enhancing the biodegradability of 2,4-DNT. Overall, the combined 3D/EF process with a G/β-PbO2 anode has relatively high efficiency in degrading solutions containing DNT and can be considered a viable treatment option for wastewater containing substances such as 2,4-DNT. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Herein, we present a method for the homogeneous hydrogenation of nitroarenes to produce anilines using low catalyst loading (1 mo%) of copper N‐heterocyclic carbene complexes as the catalyst and ammonia borane as the source of hydrogen. A wide range of nitroarenes, featuring diverse functional groups, were selectively transformed into their corresponding primary aromatic amines with high yields. This process can be readily scaled up and exhibits compatibility with various sensitive functional groups, including halogen, trifluoromethyl, aminomethyl, alkenyl, cyano, ester, amide, and hydroxyl. Notably, this catalytic methodology finds application in the synthesis of essential drug compounds. Mechanistic investigations suggest that the in‐situ‐generated Cu‐H species may serve as active intermediates, with reduction pathways involving species such as azobenzene, 1,2‐diphenylhydrazine, nitrosobenzene, and N‐phenylhydroxylamine. [ABSTRACT FROM AUTHOR]

This review delves into recent advancements in the field of nitro(het)aromatic bioreductive agents tailored for hypoxic environments. These compounds are designed to exploit the low-oxygen conditions typically found in solid tumors, making them promising candidates for targeted cancer therapies. Initially, this review focused on their role as gene-directed enzyme prodrugs, which are inert until activated by specific enzymes within tumor cells. Upon activation, these prodrugs undergo chemical transformations that convert them into potent cytotoxic agents, selectively targeting cancerous tissue while sparing healthy cells. Additionally, this review discusses recent developments in prodrug conjugates containing nitro(het)aromatic moieties, designed to activate under low-oxygen conditions within tumors. This approach enhances their efficacy and specificity in cancer treatment. Furthermore, this review covers innovative research on using nitro(het)aromatic compounds as fluorescent probes for imaging hypoxic tumors. These probes enable non-invasive visualization of low-oxygen regions within tumors, providing valuable insights for the diagnosis, treatment planning, and monitoring of therapeutic responses. We hope this review will inspire researchers to design and synthesize improved compounds for selective cancer treatment and early diagnostics. [ABSTRACT FROM AUTHOR]

Since catalytic chemoselective reduction of corresponding nitroarenes is a significant route to produce functionalized anilines, developing inexpensive and highly active catalyst is imperia. Herein, the Co‐Ce‐H2salen‐hmta composite was first prepared by grinded completely the mixture of Co‐H2Salen and hexamethylenetetramine (hmta) in 1:1 mol ratio in a mortar. The 3d–4f hetero‐metal Co‐Ce‐H2salen coordination polymer acted as a support precursor and hmta provided the nitrogen source. Then, a target catalyst of Co/NC‐CeO2‐hmta were afforded by pyrolysis of Co‐Ce‐H2salen‐hmta composite at 800°C in the presence of argon atmosphere. When the target catalyst of Co/NC‐CeO2‐hmta and reference catalysts were applied for the hydrogenation of nitroarenes under N2H4, the target catalyst of Co/NC‐CeO2‐hmta exhibited better performance than reference catalysts in terms of conversion, yield, selectivity, and recyclability. Spectral analysis suggested that the high catalytic performance of a target catalyst of Co/NC‐CeO2‐hmta were attributed to highly dispersed metallic Co0, rich oxygen vacancies, and nitrogen‐doped carbon matrix. [ABSTRACT FROM AUTHOR]

This paper outlines a novel strategy for the preparation of seven-membered-ring lactams from simple nitroarenes. The approach is based on a photochemical dearomative ring expansion starting with the conversion of the nitro group into a singlet nitrene. This process is mediated by blue light, occurs at room temperature and overall enables the insertion of the nitro N -atom into the benzenoid framework. This step transforms the aromatic starting material into a seven-membered ring azepine that, following hydrogenation and hydrolysis, is converted into the desired caprolactams in just three steps. [ABSTRACT FROM AUTHOR]

Since catalytic chemoselective reduction of corresponding nitroarenes is a significant route to produce functionalized anilines, developing inexpensive and highly active catalyst is imperia. Herein, the Co‐Ce‐H2salen‐hmta composite was first prepared by grinded completely the mixture of Co‐H2Salen and hexamethylenetetramine (hmta) in 1:1 mol ratio in a mortar. The 3d–4f hetero‐metal Co‐Ce‐H2salen coordination polymer acted as a support precursor and hmta provided the nitrogen source. Then, a target catalyst of Co/NC‐CeO2‐hmta were afforded by pyrolysis of Co‐Ce‐H2salen‐hmta composite at 800°C in the presence of argon atmosphere. When the target catalyst of Co/NC‐CeO2‐hmta and reference catalysts were applied for the hydrogenation of nitroarenes under N2H4, the target catalyst of Co/NC‐CeO2‐hmta exhibited better performance than reference catalysts in terms of conversion, yield, selectivity, and recyclability. Spectral analysis suggested that the high catalytic performance of a target catalyst of Co/NC‐CeO2‐hmta were attributed to highly dispersed metallic Co0, rich oxygen vacancies, and nitrogen‐doped carbon matrix. [ABSTRACT FROM AUTHOR]

The environmental contaminant 1,3-Dinitrobenzene (1,3-DNB), which contains two nitro groups (-NO2), has a +III nitrogen atom oxidation state, and is susceptible to electron acceptance, and subsequent reductive degradation. In this study, carpet grass was investigated as a potential source of polyphenols for the reductive degradation of 1,3-DNB. A characterization of carpet grass revealed a rapid release of polyphenols from the grass in aqueous solution, and an increase in reduction capacity. The effects of the amount of grass in solution, and effects of the pH of the aqueous phase were examined. It was found that higher grass doses (e.g., 50 g L-1) in solution resulted in complete removal of 1,3-DNB in the aqueous phase after 7 d reaction, regardless of the pH level. Kinetic analysis of 1,3-DNB degradation and its reaction intermediates, 3-nitroaniline (3-NA) and 1,3-phenylenediamine, indicated that the overall observed degradation rates (2.51-3.17 × 10-2 h-1) were similar across different doses of carpet grass, but found that the dose did impact the formation and degradation of 3-NA. Based on the results, a potential soil mixing treatment for 1,3-DNB contaminated soils, consisting of the blending of carpet grasses with soils was proposed. Soil slurry experiments simulating field remediation application suggested that enhanced degradation of 1,3-DNB contaminated soils can be achieved under reaction conditions with an appropriate solution volume and sufficiently high grass doses. This research offers valuable insights into the utilization of carpet grass for potential soil remediation through its incorporation into soils contaminated with 1,3-DNB. [ABSTRACT FROM AUTHOR]

This articles describes the preparations of a series of Schiff base ligands [L1], [L2], and [L3] and their corresponding copper(II) complexes; [C1], [C2] and [C3]. The synthesized ligands and their copper(II) complexes were characterized using Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR) and Ultraviolet-visible (UV-Vis) spectroscopy. The ability of the compounds to inhibit bacteria species were tested against E. Coli, Staphyllococcus and Streptococcus bacterial. The results revealed that all the compounds were active against bacteria species. The inhibition rate is in order L3>L2>L1 for ligands and C3>C2>C1 for complexes. The catalytic activities of the synthesized copper(II) complexes were evaluated in the reduction of aromatic compounds in the presence of sodium borohydride which acts as reducing agent. The progress of reaction was monitored using UV-visible spectroscopy and the percentage conversion was determined from the spectroscopy data. The results showed that [C3] has the highest catalytic activities with 97.5% conversion, followed by [C2] complex with 95.2% conversion, then [C1] complex with 90.8% conversion. The optimization of the catalyst dose shows that 1.0 mg of the catalyst dose was the most optimized amount with the highest conversion of 94.6% than other dose of 0.5 mg (92.4%) and 1.5 mg (91.4%). Recyclability and reproducibility tests of copper(II) complexes confirmed that all the three complexes were active, efficient and possess excellent reproducibility with consistent catalytic performances and could be re-used again without significant decrease in the catalytic activities. [ABSTRACT FROM AUTHOR]

2,4-Dinitrotoluene (2,4-DNT) is a broadly applied nitroaromatic compound with multiple applications, and its simple production has resulted in its extensive utilization in producing explosives, dyes, and rubber. This substance is hazardous and induces genetic mutations in humans, fish, and microorganisms. Thus, this research was done to assess the effectiveness of the three-dimensional electro-Fenton (3D/EF) process employing magnetic activated carbon particle electrodes (GAC/Fe3O4) in eliminating 2,4-dinitrotoluene from water-based solutions. In this experimental investigation, Fe3O4 nanoparticles were created using the chemical co-precipitation technique. The G/β-PbO2 anode was fabricated by electrochemically depositing PbO2 layers on graphite sheets. G/β-PbO2 and stainless steel were utilized as the anode and cathode, respectively. The structure, particle size, and properties of the GAC/Fe3O4 nanocomposite were analyzed using FESEM, XRD, and EDX. The morphology of the G/β-PbO2 electrode was also examined using SEM. The Taguchi experimental design method was employed to identify the optimal conditions. The outcomes demonstrated that higher reaction time and current density, as well as lower pH and pollutant concentration, resulted in improved 3D/EF efficiency. Accordingly, the optimum values of parmeters were identified to be a concentration of 2,4-DNT = 50 mg/L, pH = 3, electrolysis time = 100 min, and current density = 8 mA/cm2. With these parameters, the degradation efficiency of 2,4-DNT through the examined system was 98.42 %, alongside removal efficiencies of 84.69 % for COD and 79.67 % for TOC. Additionally, the results indicated an increase in the average oxidation state (AOS) (from 1.27 to 1.95) and carbon oxidation state (COS) (from 1.27 to 2.75) in the 3D/EF process, along with a decrease in the COD/TOC ratio (from 1.81 to 1.36), indicating the effectiveness of the 3D/EF system in enhancing the biodegradability of 2,4-DNT. Overall, the combined 3D/EF process with a G/β-PbO2 anode has relatively high efficiency in degrading solutions containing DNT and can be considered a viable treatment option for wastewater containing substances such as 2,4-DNT. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds (NACs) with electron-withdrawing nitro (-NO2) groups are typical refractory pollutants. Despite advanced oxidation processes (AOPs) being appealing degradation technologies, inefficient ring-opening oxidation of NACs and practical large-scale applications remain challenges. Here we tackle these challenges by designing a reduction-oxidation coupling (ROC) degradation process in LaFe0.95Cu0.05O3@carbon fiber cloth (LFCO@CFC)/PMS/Vis continuous flow system. Cu doping enhances the photoelectron transfer, thus triggering the -NO2 photoreduction and breaking the barriers in the ring opening. Also, it modulates surface electronic configuration to generate radicals and non-radicals for subsequent oxidation of reduction products. Based on this, the ROC process can effectively remove and mineralize NACs under the environmental background. More importantly, the LFCO catalyst outperformed most of the recently reported catalysts with lower cost (13.72 CNY/ton) and higher processing capacity (3600 t/month). Furthermore, the high scalability, material durability, and catalytic activity of LFCO@CFC under various realistic environmental conditions prove the potential ability for large-scale applications. Nitroaromatic compounds (NACs) with electron-withdrawing -NO2 groups are typical refractory pollutants. Here the authors designed the LaFe0.95Cu0.05O3@carbon fiber cloth (LFCO@CFC) to realize efficient reduction-oxidation coupling degradation of NACs with lower cost and higher durability. [ABSTRACT FROM AUTHOR]

In catalytic reactions, the diverse binding sites of nanometals located in nanomaterials considerably influence the activity of nanocatalysts. In this study, the special nanostructure and charge distribution of halloysite nanotubes (HNTs) incorporating a weak reducing agent closo-dodecaborate (closo-[B12H12]2-) were leveraged to immobilize Au nanoparticles (NPs) on the inner and outer surfaces of HNTs. The introduction of closo-[B12H12]2- into HNTs was achieved via vacuum extraction and acid immersion. Subsequently, nanocatalysts loaded with Au NPs on the diverse surfaces of the HNTs were obtained from a direct reaction with a KAuCl4 solution. The Au NPs loaded on the inner surface of the HNTs were found to have highly dispersed and exhibited excellent catalytic activity in the reduction of nitroaromatics. At room temperature, the Au NPs loaded on the inner surface of the HNTs with a mass fraction of 0.02% showed a high turnover frequency value of 47.28 min-1 in a model reaction of the catalytic reduction of 4-nitrophenol to 4-aminophenol and exhibited excellent stability in cycling tests. Therefore, this study provides a new approach for synthesizing nanocomposites for various practical applications. [ABSTRACT FROM AUTHOR]

Nitroreductases are the enzymes that can convert nitroaromatic substances including explosives like TNT to their corresponding nitrite, hydroxylamine or amino derivatives with reduced NADH or NADPH as an electron donor. A wide range of nitroreductases are known to present in bacterial genomes that are explored for their potential in the reduction of nitroaromatic compounds and they are used in converting prodrugs to toxic hydroxylamine derivatives causing tumor cell killing. Likewise, in cancer cells, the low oxygen condition called hypoxia is a characteristic of solid tumors and during hypoxia nitroreductase gene expression occurs. Moreover, due to the ability of nitroreductases to reduce nitroaromatic compounds, phytoremediation potential of plants was inspected by expressing bacterial nitroreductase genes in plants through genetic engineering. Due to its diversity and widespread applications in different biosystems, its detection has gained momentum among the scientific community. Designing fluorescent probes for detecting nitroreductases has emerged as a beneficial tool compared to conventional monitoring approaches due to their high sensitivity, selectivity, and real‐time monitoring ability. This review aims to provide an understanding of the activity and the status of nitroreductases in bacteria, plants and animal cells as well as the significance of fluorescent imaging‐related studies by employing recently designed probes. [ABSTRACT FROM AUTHOR]

The effective transition metal‐free photoredox/bismuth dual catalytic reductive dialkylation of nitroarenes with benzaldehydes has been reported. The nitroarene reduction through visible light‐driven photoredox catalysis was integrated with subsequent reductive dialkylation of anilines under bismuth catalysis to enable the cascade reductive alkylation of nitroarenes with carbonyls. Salient features of this relay catalysis system include mild reaction conditions, no requirement for transition metal catalysts, easy handling, step‐economy, and high selectivity. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of nitroarenes allows direct access to manifold nitrogen containing heterocycles. This work reports the simple and direct electro-organic synthesis of 18 different examples of 2H,4H-4-hydroxy-1,4-benzoxazin-3-ones in up to 81% yield. The scalability of the method was demonstrated on a gram-scale. [ABSTRACT FROM AUTHOR]

Ruthenium nanoparticles stabilised by an amine‐modified Ordered Mesoporous Silica Immobilized Ionic Liquid (OMSIIL) are efficient catalysts for the partial reduction of nitrobenzene to hydrazobenzene with 100 % selectivity as well as the complete reduction to aniline. High selectivity for the partial reduction of nitrobenzene to hydrazobenzene was obtained when the reaction was conducted in ethanol with 0.5 mol% catalyst and NaBH4 as the hydrogen donor whereas aniline was obtained as the sole product in water when dimethylamine borane (DMAB) was used as the hydrogen donor. Interestingly, while a range of electron poor nitroarenes were reduced to the corresponding hydrazoarene with high selectivities and good conversions, nitroarenes substituted with electron donating groups resulted in complete reduction to the aniline. Composition‐time profiles suggest that reductions conducted in ethanol with sodium borohydride occur via the condensation pathway while those conducted in water using dimethylamine borane as the hydrogen source may well go via the direct pathway. This is the first example of the selective reduction of nitrobenzene to hydrazobenzene using a ruthenium nanoparticle‐based catalyst and the initial TOF of 320 mol nitrobenzene converted mol Ru−1 h−1 for the partial reduction of nitrobenzene to hydrazobenzene is markedly higher than previous literature reports. A study of the catalyst performance as a function of the surface modification revealed that each component has a direct and dramatic effect on the efficacy as RuNPs stabilised by COK‐12 modified with imidazolium‐based ionic liquid and a primary amine gave the highest conversion while selective removal of either component or replacement of the primary amine with a tertiary amine resulted in a marked reduction in efficiency. [ABSTRACT FROM AUTHOR]

Schiff bases with pyrene, anthracene or naphthalene groups can act as simple, sensitive, and selective sensors for the detection of trace explosives. We have prepared three new types of Schiff bases with fluorescent properties as fluorescent probes for use in the fluorescence detection of explosives. The detection properties of the synthesized compounds of photophysical and fluorescent explosives were investigated. Spectroscopic methods were used for the structural characterization of the compounds. Within the scope of the study, compounds (A, B and C) were used as fluorescent probes in the detection of some explosives and the data obtained were recorded. Instead of the quenching effect expected by the explosives on the emissions of the compounds, it was observed in some experiments that the emission intensity due to aggregation increased. In addition, the color measurements (CIE standards) and Color temperature (CCT) of the compounds were calculated. [ABSTRACT FROM AUTHOR]