The reduction of nitrobenzene to aniline is very important for both pollution control and chemical synthesis. Nevertheless, difficulties still remain in developing a catalytic system having high efficiency and selectivity for the production of aniline. Herein, it was found that PdO nanoparticles highly dispersed on TiO2 support (PdO/TiO2) functioned as a highly efficient catalyst for the reduction of nitrobenzene in the presence of NaBH4. Under favorable conditions, 95% of the added nitrobenzene (1 mmol/L) was reduced within 1 min with an ultra-low apparent activation energy of 10.8 kJ/mol by using 0.5%PdO/TiO2 as catalysts and 2 mmol/L of NaBH4 as reductants, and the selectivity to aniline even reached up to 98%. The active hydrogen species were perceived as dominant species during the hydrogenation of nitrobenzene by the results of isotope labeling experiments and ESR spectroscopic. A mechanism was proposed as follows: PdO activates the nitro groups and leads to in-situ generation of Pd, and the generated Pd acts as the reduction sites to produce active hydrogen species. In this catalytic system, nitrobenzene prefers to be adsorbed on the PdO nanoparticles of the PdO/TiO2 composite. Subsequently, the addition of NaBH4 results in in-situ generation of a Pd/PdO/TiO2 composite from the PdO/TiO2 composite, and the Pd nanoclusters would activate NaBH4 to generate active hydrogen species to attack the adsorbed nitro groups. This work will open up a new approach for the catalytic transfer hydrogenation of nitrobenzene to aniline in green chemistry.

A catalyst- and additive-free synthesis of 2-benzyl N-substituted anilines from (E)-2-arylidene-3-cyclohexenones and primary amines has been reported. The reaction proceeds smoothly through a sequential imine condensation-isoaromatization pathway, affording a series of synthetically useful aniline derivatives in acceptable to high yields. Mild reaction conditions, no requirement of metal catalysts, operational simplicity and the potential for scale-up production are some of the highlighted advantages of this transformation.

BACKGROUND: Nitroaromatic compounds are inherently hazardous and explosive, so convenient and rapid detection strategies are needed for the sake of human health and the environment. There is an urgent demand for chemical sensing materials that offer high sensitivity, operational simplicity, and recognizability to effectively monitor nitroaromatic residues in industrial wastewater. Despite its importance, the mechanisms underlying fluorescence quenching or enhancement in fluorescent sensing materials have not been extensively researched. The design and synthesis of multiresponsive fluorescent sensing materials have been a great challenge until now.
RESULTS: In this study, a one-dimensional Cd-based fluorescent porous coordination polymer (Cd-CIP-1) was synthesized using 5-(4-cyanobenzyl)isophthalic acid (5-H2CIP) and 4,4\'-bis(1-imidazolyl)biphenyl (4,4\'-bimp) and used for the selective detection of nitrobenzene in aqueous solution by fluorescence quenching, with a limit of detection of 1.38 × 10-8 mol L-1. The presence of aniline in the Cd-CIP-1 solution leads to the enhancement of fluorescence property. Density functional theory and time-dependent density functional theory calculations were carried out to elucidate the mechanisms of the fluorescence changes. This study revealed that the specific pore size of Cd-CIP-1 facilitates analyte screening and enhances host-guest electron coupling. Furthermore, π-π interactions and hydrogen bond between Cd-CIP-1 and the analytes result in intermolecular orbital overlap and thereby boosting electron transfer efficiency. The different electron flow directions in NB@Cd-CIP-1 and ANI@Cd-CIP-1 lead to fluorescence quenching and enhancement.
UNASSIGNED: The multiresponsive coordination polymer (Cd-CIP-1) can selectively detect nitrobenzene and recognize aniline in aqueous solutions. The mechanism of fluorescence quenching and enhancement has been thoroughly elucidated through a combination of density functional theory and experimental approaches. This study presents a promising strategy for the practical implementation of a multiresponsive fluorescent chemical sensor.

The selective electrocatalytic reduction of nitrobenzene (NB) to aniline demands a desirable cathodic catalyst to overcome the challenges of the competing hydrogen evolution reaction (HER), a higher overpotential, and a lower selectivity. Here, we deposit Co-doped 1T MoS2 on Ti mesh by the solvothermal method with different doping percentages of Co as x % Co-MoS2 (where x = 3, 5, 8, 10, and 12%). Because of the lowest overpotential, lower charge-transfer resistance, strong suppression of the competing HER, and higher electrochemical surface area, 8% Co-MoS2 achieves 94% selectivity of aniline with 54% faradaic efficiency. The reduction process follows first-order dynamics with a reaction coefficient of 0.5 h-1. Besides, 8% Co-MoS2 is highly stable and retains 81% selectivity even after 8 cycles. Mechanistic studies showed that the selective and exothermic adsorption of the nitro group at x % Co-MoS2 leads to a higher rate of NB reduction and higher selectivity of aniline. The aniline product is successfully removed from the solution by polymerization at FTO. This study signifies the impact of doping metal atoms in tuning the electronic arrangement of 1T-MoS2 for the facilitation of organic transformations.

The sulfate radical-based advanced oxidation processes (SR-AOPs) is a promising method for the degradation of pollutants, with the development of highly efficient catalysts for persulfate activation has been widely concerned. The novel BiCoFe-LDH (BCF-x) was synthesized successfully by coprecipitation method, which can activate peroxydisulfate (PDS) efficiently to degrade aniline. Comparative analysis with pure CoFe-LDH revealed a remarkable increase in reaction rate constant by approximately 14.66 times; the degradation rate of aniline (10 mg/L) was 100% in 60 min with the condition of 0.5 g/L BCF-1.5 and 0.5 g/L PDS, due to BCF-1.5 which was characterized as a complex of CoFe-LDH and Bi2O2CO3, promoting electron transport to improve the efficiency of activated PDS. In the reaction system, SO4•-, ·OH, and 1O2 were responsible for the aniline degradation and ·OH was the primary one. Furthermore, this work proposes a reaction electron transfer catalytic mechanism, which provided a new insight and good application prospect for efficient activation of PDS for pollutant degradation.

Chloramination was commonly used as disinfectant for killing pathogens in water. However, in this process, nitrogen-containing disinfection by-products (N-DBPs) would accidently form and subsequently rise toxicity. Here, we investigated acute toxicity variation and by-products formation during chloramination treatment on UV filter 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone (BP-4). Under alkaline conditions, the acute toxicity of this system had significant increase. A total of 17 transformation products were tentatively identified, and for them, plausible transformation pathways were proposed. Noticeably, numerous aniline and nitrosobenzene analogs were detected, and the dramatic increase of acute toxicity in this system might be primarily attributed to the formation of benzoquinone and aniline analogs. Besides, bromophenol, iodophenol and iodobenzoquinone analogs exhibiting high toxicity were generated in the presence of bromine and iodide ions. This study indicates that chloramination treatment may significantly increase potential health risk, further management on disinfection system is reasonable.

Aniline compounds, as a class of widely used but highly toxic chemical raw materials, are increasingly being released and accumulated in the environment, posing serious threats to environmental safety and human health. Therefore, developing detection methods for aniline compounds is of particular significance. Herein, we synthesized the fluorescent third monomer cyano-stilbene epoxide M and ternary copolymerized it with carbon dioxide (CO2) and propylene oxide (PO) to synthesize carbon dioxide-based polycarbonate (PPCM) with fluorescence recognition functions, as well as excellent performance, for the first time. The results revealed that the PPCM fluorescent probe exhibited typical aggregation-induced luminescence properties and could be quenched by aniline compounds. The probe presented anti-interference-specific selectivity for aniline compounds, and the detection limit was 1.69 × 10-4 M. Moreover, it was found to be a highly sensitive aniline detection probe. At the same time, the aniline biomarker p-aminophenol in urine could also be detected, which could expand the potential applications of polymers in the fluorescence-sensing field.

This study selected a contamination site associated with pesticide production to investigate the impact of soil settlement induced by pumping on the migration and transformation of the principal pollutant, aniline. The TMVOC model was enhanced by incorporating the settlement effect and validated through a soil-column experiment, which examined aniline distribution, phase transformation, and remediation efficiency under soil settlement. The results indicate that the optimized TMVOC model can accurately simulate the impact of pumping-induced soil settlement on aniline removal. The longitudinal migration of aniline was reduced, with the area of high concentrations drawing nearer to the surface. Furthermore, soil settlement negatively affected the removal of aniline in the Non-Aqueous Phase Liquid (NAPL) phase, resulting in a 10.59 % decline in the removal rate. In contrast, soil settlement positively influenced aniline removal in the gas and aqueous phases, increasing the removal rate by 12.55 % and 5.04 %, respectively, with the gas phase showing the most significant increase. Soil porosity decreased due to soil settlement, leading to a change in the proportion of each phase, with NAPL increasing after remediation. Additionally, soil settlement exhibited hysteresis, as evidenced by a noticeable decrease in the removal rate in the 10th month of the remediation process, and the final mass removal rate was reduced by 5.93 %.

Aniline is a widely used chemical. Chronic or high-dose exposure to aniline can lead to hepatocellular damage. Although the hepatic pathogenicity of aniline has been established in previous studies, studies involving pathogenic genes during aniline-induced liver injury are limited. Our study first discovered and identified the role and mechanism underlying a new circRNA mmu_circ_26984 in aniline-induced chemical liver injury. Further, we discuss the protective effect of N-acetylcysteine (NAC) in this pathway. After constructing in vitro and in vivo models of aniline treatment, we screened the circRNA with significant differences in expression in AML12 cells from control and aniline-treated groups by circRNA microarray analysis. Next, using RNA pulldown, liquid chromatography-mass spectrometry (LC-MS), and RNA immunoprecipitation, we analyzed the relationship between mmu_circ_26984 and myosin heavy chain 9 (Myh9). Subsequently, we determined the specific mechanism of action of mmu_circ_26984 and Myh9 in aniline-induced liver injury and the protective effect of NAC against aniline-induced liver injury process using Cell Counting Kit-8, Western blot, RNA extraction, a reverse transcription quantitative polymerase chain reaction (RT-qPCR), fluorescence in situ hybridization, immunohistochemistry, and immunofluorescence. The expression of mmu_circ_26984 was significantly increased in liver tissues and AML12 cells of aniline-treated mice compared with the control group. This high expression of mmu_circ_26984 increased the expression of injury-related inflammatory factors, such as NLRP3, Caspase-1, IL-18, and IL-1β in vivo and ex vivo, which exacerbated the level of liver injury. The interaction of mmu_circ_26984 with Myh9 also affected the course of liver injury. Mmu_circ_26984 overexpression and reduced treatment affected the levels of Myh9 expression in AML12 cells, as well as downstream inflammatory factors associated with injury, such as NLRP3. In addition, NAC reduced the process of liver injury mediated by the mmu_circ_26984/Myh9/NLRP3 axis. In conclusion, mmu_circ_26984 is a potential molecular marker and therapeutic target in the process of aniline-induced liver injury that can mediate aniline-exposure-induced liver injury via modulation of the mmu_circ_26984/Myh9/NLRP3 axis, and NAC can effectively attenuate the effect of this liver injury.

Despite that extensive efforts have been dedicated to the search for advanced catalysts to boost the electrocatalytic nitrobenzene reduction reaction (eNBRR), its progress is severely hampered by the limited understanding of the relationship between catalyst structure and its catalytic performance. Herein, this review aims to bridge such a gap by first analyzing the eNBRR pathway to present the main influential factors, such as electrolyte feature, applied potential, and catalyst structure. Then, the recent advancements in catalyst design for eNBRR are comprehensively summarized, particularly about the impacts of chemical composition, morphology, and crystal facets on regulating the local microenvironment, electron and mass transport for boosting catalytic performance. Finally, the future research of eNBRR is also proposed from the perspectives of performance enhancement, expansion of product scope, in-depth understanding of the reaction mechanism, and acceleration of the industrialization process through the integration of upstream and downstream technologies.