Aromatic Dinitro Compounds Research Articles

Investigating the synergistic effect of RuO2 nanoparticle-decorated V2O5 nanoflakes for sensitive detection of 2,4-dinitrophenol and 2,4-dinitrotoluene

The dinitroaromatic compounds 2,4-Dinitrophenol (2,4-DNP) and 2,4-Dinitrotoluene (2,4-DNT) are prevalent contaminants in various water sources due to their extensive use in explosive synthesis and other industrial applications. The highly toxic and carcinogenic nature of these compounds poses significant risks to human health and environment, making the development of facile, rapid, cost-effective, and selective detection methods crucial. This research presents the one-step hydrothermal synthesis of RuO2 nanoparticle-decorated V2O5 nanoflakes to fabricate an electrochemical sensor for the detection of 2,4-DNP and 2,4-DNT. The synthesized materials were characterized using XRD, Raman spectroscopy, FESEM, HRTEM, and XPS techniques. The electrochemical behavior of 2,4-DNP and 2,4-DNT was investigated using cyclic voltammetry, square wave voltammetry and chronoamperometry. Under optimized conditions, 2,4-DNP and 2,4-DNT exhibited two reduction peaks corresponding to the nitro-functional groups on the aromatic ring. Notably, the 7 wt% RuO2 in V2O5 nanocomposite-modified glassy carbon electrode (RV7/GCE) demonstrated the lowest detection limits of 1.07 nM and 1.01 nM within the linear dynamic range (LDR) of 5.0 nM–35.0 µM for 2,4-DNP, and 2,4-DNT, respectively. Furthermore, the sensor exhibited excellent reusability and reproducibility, delivering consistent results for both laboratory-controlled and real-world samples. This advancement offers efficient detection and monitoring of these hazardous compounds in environmental and industrial settings.

Membraneless Ionic Liquid Droplet Nanoprobe for Vapor Sensing and Gas Phase Scanning Electrochemical Microscopy

Gas phase sensing of volatile chemicals is a critical area of research relevant to biomedical diagnosis and environmental hazard assessment. Among various types of sensors, electrochemical sensors garnered attention as cost-effective and portable methods. Most electrochemical sensors needed the membrane to prevent solvent evaporation for detecting the gaseous species. However, the presence of the membrane induced slow response time due to the penetration of gas molecules through the membrane. To improve the systems, a membraneless ionic liquid droplet nanoprobe was developed. Gaseous species can permeate the thin ionic liquid layer, which was also used as the electrolytes, and react on the electrode in extremely fast response. Furthermore, nano-sized electrode makes available to detect sensitively with low charging capacitance. Using the probe type form factor, application to gas phase scanning electrochemical microscopy (SECM) was attempted with high spatial resolution. Oxygen detection, the most commonly studied, was implemented for the first application of the ionic liquid nanoprobe. The limit of detection of this probe was 13 ppm, which is extremely good for electrochemical oxygen sensors. Also, the fast response (< 0.1 s) made the mapping of oxygen concentration using SECM. The nanoprobe showed more than a hundred times better spatial resolution (several micrometer scale) than the previous gas phase SECM study mapping the oxygen. As the application of this oxygen probe, Li-air battery analysis can be conducted. Oxygen was used in the reaction at the cathode of the Li-air battery. As mapping the oxygen concentration above the cathode, It is expected that structural causes for the irreversibility at the cathode can also be found. As oxygen sensing, other electrochemical active gaseous species can be detected with the electrochemical sensor. Trinitrotoluene is a well-known explosive compound, and it can be detected in electrochemistry. Due to its low vapor pressure, di-nitroaromatic compounds, like dinitrotoluene (DNT), dinitrobenzene (DNB), and dinitrophenol (DNP), were used as explosive footprints, which have higher vapor pressure and have often been identified as marker molecules. Using our ionic liquid nanoprobe, we developed the nitroaromatic compounds (NACs) sensor for real-time detection of trace vapors, without any sample pre-treatment and at room temperature. Furthermore, in a simulated airport carousel, real-time and preemptive NACs detection was demonstrated with fast response time. As oxygen detection, gas phase SECM was conducted and 3D mapping capability of the differential vapor pressure was demonstrated, exercising the potential of the NACs nanoprobe in locating the source of an explosive risk. With the sensitive sensing performance of nanoprobe, it can be used as breath analysis. There are several biomarkers to indicate certain diseases. For example, acetone is a representative biomarker of diabetes. Using this sensing platform, acetone sensing was implemented, and it may be used for the initial detection of diabetes.

Micropacked‐bed Reactor for Continuous Hydrogenation of Aromatic Dinitro Compounds

AbstractDue to the intricacy aromatic dinitro compound hydrogenation processes, it is difficult to attain high conversion and selectivity using merely modified catalysts in batch reactors. The micropacked‐bed reactor (μPBR) offers efficient heat and mass transfer, a precise and controllable reaction process, and a high level of safety. In this work, the hydrogenation of 2,4‐dinitroanisole was selected as the model reaction, and a variety of catalysts were utilized in the continuous flow system based on μPBR for hydrogenation of 2,4‐dinitroanisole. During 960 minutes of operation, the synthesis of 2,4‐diaminoanisole was carried out using a Pd (OH)2/C catalyst and the optimal process condition, yielding 100 % conversion, 99.5 % selectivity, and the favorable durability. For the hydrogenation of relevant aromatic dinitro compounds, the continuous flow system demonstrates exceptional performance.

Formation and influence factors of halonitromethanes in chlorination of nitro-aromatic compounds

Halonitromethanes (HNMs), typical nitrogenous disinfection byproducts generated during disinfection of chlorination and chloramination, are widely detected in drinking water. This study investigated the formation of two dominant HNMs, trichloronitromethane (TCNM) and dichloronitromethane (DCNM) during chlorination/chloramination of ten nitro-aromatic compounds (NACs), including six aromatic mono-nitro compounds, three aromatic di-nitro compounds and one aromatic tri-nitro compound. The results showed that 2-nitrophenol and 3-nitrophenol could be the main precursors of TCNM and DCNM, and the yields of TCNM were one order of magnitude higher than that of DCNM. HNMs formation in chlorination was much higher than that in chloramination. However, HNMs were hardly produced during chlorination and chloramination of the other eight NACs. In chlorination of 2-nitrophenol, a pH range of 5.0–7.0 facilitated the TCNM formation. Besides, the concentration of ferric and manganese ions had different influences on TCNM formation. While the concentration ranges were 0–2 mg/L, ferric ion significantly decreased TCNM formation but manganese ion had not any influence on TCNM formation. Contrary to a previous finding, nitrite significantly reduced TCNM formation, which implied that nitrite has different effects on TCNM formation from various precursors. Moreover, dissolved organic matter (DOM, 0–5 mg/L as C) significantly influenced the formation of TCNM in chlorination of 2-nitrophenol despite the low TCNM formation in chlorination of DOM. Several chlorinated intermediates were detected and identified as mono/di/tri-chloro-2-nitrophenol during chlorination of 2-nitrophenol. It is effectively to reduce the production of TCNM and DCNM formation from chlorination of 2-nitrophenol by controlling disinfection conditions in drinking water.

Biogenic, urban, and wildfire influences on the molecular composition of dissolved organic compounds in cloud water

Abstract. Organic aerosol formation and transformation occurs within aqueous aerosol and cloud droplets, yet little is known about the composition of high molecular weight organic compounds in cloud water. Cloud water samples collected at Whiteface Mountain, New York, during August–September 2014 were analyzed by ultra-high-resolution mass spectrometry to investigate the molecular composition of dissolved organic carbon, with a focus on sulfur- and nitrogen-containing compounds. Organic molecular composition was evaluated in the context of cloud water inorganic ion concentrations, pH, and total organic carbon concentrations to gain insights into the sources and aqueous-phase processes of the observed high molecular weight organic compounds. Cloud water acidity was positively correlated with the average oxygen : carbon ratio of the organic constituents, suggesting the possibility for aqueous acid-catalyzed (prior to cloud droplet activation or during/after cloud droplet evaporation) and/or radical (within cloud droplets) oxidation processes. Many tracer compounds recently identified in laboratory studies of bulk aqueous-phase reactions were identified in the cloud water. Organosulfate compounds, with both biogenic and anthropogenic volatile organic compound precursors, were detected for cloud water samples influenced by air masses that had traveled over forested and populated areas. Oxidation products of long-chain (C10−12) alkane precursors were detected during urban influence. Influence of Canadian wildfires resulted in increased numbers of identified sulfur-containing compounds and oligomeric species, including those formed through aqueous-phase reactions involving methylglyoxal. Light-absorbing aqueous-phase products of syringol and guaiacol oxidation were observed in the wildfire-influenced samples, and dinitroaromatic compounds were observed in all cloud water samples (wildfire, biogenic, and urban-influenced). Overall, the cloud water molecular composition depended on air mass source influence and reflected aqueous-phase reactions involving biogenic, urban, and biomass burning precursors.

Highly Selective Room Temperature Monoreduction of Dinitro‐arenes by Hydrogen Sulfide under Liquid–Liquid Biphasic Catalysis

ABSTRACTSelective reduction of one of the nitro group present in dinitro aromatic compounds by a novel Zinin reagent, H2S‐laden N‐methyldiethanolamine (MDEA) solution, has been explored in the presence of tetra‐n‐butyl phosphonium bromide as a phase transfer catalyst under the liquid–liquid mode of reaction. Under the room temperature reaction condition, reduction of 2,4‐dinitrotoluene (2,4‐DNT) with H2S‐laden MDEA leads to the selective reduction of one nitro group present either at the fourth position to obtain 4‐amino‐2‐nitrotoluene (4A2NT) or at the second position to get 2‐amino‐4‐nitrotoluene (2A4NT). The reaction was very fast to achieve 100% conversion, and the selectivity of 4A2NT is much higher than the 2A4NT. A detailed parametric study was performed to analyze the effect of parameters on 2,4‐DNT conversion and selectivity of both the isomers. The apparent activation energy was found to be as high as 46.25 kJ/mol, and the reaction was found to be kinetically controlled. An empirical kinetic model has been developed to correlate with the conversion version time data obtained experimentally. The present system dealt with an industrial problem in dealing with H2S, present in by‐product gaseous streams of many petroleum and natural gas industries. Novelties in the selective monoreduction lie in that fact that the reaction was done at room temperature (303 K), with a novel reagent, H2S‐laden MDEA solution. Therefore waste‐minimization was effected to yield value‐added fine chemicals, that is, amines.

Inclusion complexes of β-cyclodextrin-dinitrocompounds as UV absorber for ballpoint pen ink

2,4-Dinitrophenol (2,4-DNP), 2,4-dinitroaniline (2,4-DNA), 2,6-dinitroaniline (2,6-DNA) and 2,6-dinitrobenzoic acid (2,6-DNB) has appeared for the UV absorption bands in different wavelength region below 400nm, a combination of these dinitro aromatic compounds gave the broad absorption spectra within the UV region. The absorption intensities have been increased by preparation of the inclusion complex of dinitro compounds with β-cyclodextrin (β-CD). Prepared inclusion complexes are used to improve the UV protection properties of the ball point pen ink against photo degradation. The formation of solid inclusion complexes was characterized by FT-IR, and 1H NMR spectroscopy. The UV protecting properties of these inclusion complexes were calculated their sun protection factor (SPF) is also discussed. The stability of the ballpoint pen ink has been confirmed by UV–Visible spectroscopic method.

Studies on inclusion complexes of 2,4-dinitrophenol, 2,4-dinitroaniline, 2,6-dinitroaniline and 2,4-dinitrobenzoic acid incorporated with β-cyclodextrin used for a novel UV absorber for ballpoint pen ink

The inclusion complexes of β-cyclodextrin with different dinitrocompounds like 2,4-dinitrophenol, 2,4-dinitroaniline, 2,6-dinitroaniline and 2,4-dinitrobenzoic acid appears the UV absorption bands in different wavelength region below 400 nm, a combination of these dinitro aromatic compounds of inclusion complexes can improve the UV protection properties of ball point pen ink against photo degradation. The formation of inclusion complexes were characterized by FT-IR, 1H NMR and 2D ROESY NMR spectroscopy. The UV protecting properties of these inclusion complexes were calculated their sun protection factor was discussed. The stability of the ballpoint pen ink has been confirmed by UV–visible spectroscopic method.

Highly Chemo‐ and Regioselective Reduction of Aromatic Nitro Compounds Catalyzed by Recyclable Copper(II) as well as Cobalt(II) Phthalocyanines

AbstractCopper/cobalt phthalocyanines were established for the first time as catalysts for the very efficient chemo‐ and regioselective reduction of aromatic nitro compounds to generate the corresponding amines. The selective reduction of nitro compounds was observed in the presence of a large range of functional groups such as aldehyde, keto, acid, amide, ester, halogen, lactone, nitrile and heterocyclic functional groups. Furthermore, the present method was found to be highly regioselective towards the reduction of aromatic dinitro compounds in a short time with high yields. In most of the cases the conversion and selectivity were &gt;99% as monitored by GC‐MS. The reduction mechanism was elucidated by UV‐vis and electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry.

Effects of Dimaine, Diacid and Dintitro Derivatives on the Inhibition of Adenosine Deaminase; Experimental, Molecular Docking and QSAR Studies

Effects of some diacid, diamine and dinitro aromatic compounds on the structure and activity of adenosine deaminase (ADA) were investigated by UV-Vis spectrophotometry in 50 mM phosphate buffer at pH = 7.5 and 27 <TEX>${^{\circ}C}$</TEX> and molecular docking studies. The results showed that all tested ligands are showing inhibition; five ligands are uncompetitive and other two ligands are mixed of competitive and noncompetetive inhibitors with majority of competitive behavior. For the later case analysis was done based on competitive inhibition. Diacids have larger size and higher inhibition constant (<TEX>$K_I$</TEX>) relative to others. A logical correlation between calculated free energy of binding and experimental values was obtained for un-competitive. Experimental and calculated data showed that competitive inhibitors are distributed near the active site of enzyme and form several cluster of ranks, whereas uncompetitive inhibitors bind to the enzyme-substrate complex and distributed far from the active site. Results of structure-activity relationship showed that, larger, more hydrophobe, less spherical and more aromatic ligands have higher inhibition constants.

Denitration of 2,4,6-Trinitrotoluene in Aqueous Solutions Using Small-Molecular-Weight Catalyst(s) Secreted by Pseudomonas aeruginosa ESA-5

The denitration of 2,4,6-trinitrotoluene (TNT) can produce mono- or dinitro aromatic compounds susceptible to microbial mineralization. In the present study, denitration of TNT and other nitro aromatic compounds was investigated with a solid-phase extract obtained from the culture supernatant of Pseudomonas aeruginosa ESA-5 grown on a chemically defined aerobic medium. When the C18 solid-phase extract containing extracellular catalysts (EC) was incubated with TNT and NAD(P)H, we observed a significant release of nitrite. The concentration of nitrite released in the reaction medium was strongly dependent on the concentration of NAD(P)H and EC. Denitration also occurred with two TNT-related molecules, 2,4,6-trinitrobenzaldehyde, and 2,4,6-trinitrobenzyl alcohol. The release of nitrite was coupled with the formation of two polar metabolites, and mass spectrometry analyses indicated that each of these compounds had lost two nitro groups from the trinitro aromatic parent molecule. During this process, the production of toxic reduced TNT metabolites was minimal. The incubation of EC with TNT, NAD(P)H, and specific scavengers of reactive oxygen species suggested the involvement of superoxide radicals (O2*-) and hydrogen peroxide in the denitration process. Results obtained in this study reveal for the first time that extracellular small-molecular-weight substance(s) of bacterial origin can serve as green catalyst(s) to initiate TNT denitration. In addition, this study gives clear evidence for the production of a TNT metabolite bearing a single nitro groupfollowing a denitration reaction with catalyst(s) of biotic origin.

Carbonylation of aromatic dinitro compounds with carbon monoxide to respective dicarbamates in the presence of the PdCl 2/Fe/I 2/Py catalytic system

The object of this study was the reductive carbonylation of 1,3-dinitrobenzene, 1,4-dinitrobenzene and 2,4-dinitrotoluene to respective dicarbamates in the presence of the PdCl 2/Fe/I 2/Py catalytic system. By increasing the catalyst amount and extending the carbonylation reaction time a 100% conversion of dinitrobenzene to the corresponding dicarbamates was achieved with a selectivity of 87, 68, and 55%, for 1,4-, 1,3-dinitrobenzene and 2,4-dinitrotoluene, respectively.

Oxygen uptake after electron transfer from donors to the triplet state of nitronaphthalenes and dinitroaromatic compounds

The effects of oxygen in the photolysis of nitroaromatic compounds, such as 1-nitronaphthalene (1NN), 1,4-dinitronaphthalene, 4,4′-dinitrobiphenyl and mono- or di-nitrofluorenone, were studied in air-saturated aqueous acetonitrile solution in the presence of donors, such as aliphatic amines, e.g. triethylamine (TEA), aromatic amino acids or ascorbic acid. The overall reaction is conversion of oxygen via the HO 2 /O 2 − radical into hydrogen peroxide. The quantum yield of oxygen uptake ( Φ - O 2 ) increases with the donor concentration. The maximum values are Φ - O 2 = 0.3 , e.g. for 1NN and 3–30 mM ascorbic acid or TEA. The photoinduced formation of H 2O 2 is initiated by triplet quenching and subsequent reaction of the donor and acceptor radicals with oxygen. The rate constant of scavenging of the nitroaromatic radical anion by oxygen is (0.6–1) × 10 7 M −1 s −1. Some specific properties of oxygen and nitroarene compounds, including the radicals involved and the pH and donor concentration dependences, were discussed.

Regio- and Chemoselective Reduction of Aromatic Nitro and Carbonyl Compounds Over Novel Bakers Yeast Immobilized Nanoporous Silicates

For the first time, Bakers yeast immobilized mesoporous MCM-41 (BY/MCM-41) is put forward as a promising heterogeneous catalyst for selective reduction of aromatic nitro and carbonyl containing compounds. The catalyst is highly efficient for the reduction of aromatic nitro and carbonyl groups to their respective amines and alcohols. It showed highly regio- and chemoselectivity for the reduction of substituted aromatic dinitro compounds and nitro compounds with carbonyl groups. The catalyst also showed promise for the chemoselective reduction of α,β-unsaturated carbonyls to allylic alcohols. In all the cases, good to excellent yield is obtained with minimal reaction time. It is also proved that the catalyst can be reused for these purposes. Keywords: Baker's yeast, mesoporous, heterogeneous catalysis, selective reduction, nitroarenes

A Convenient Method to Aniline Compounds Using Microwave-Assisted Transfer Hydrogenation

The reduction of mononitro and dinitro aromatic compounds to their aniline analogues using microwave-assisted transfer hydrogenation has been demonstrated. The optimised conditions used, with some examples, are described herein.

Quantitative structure–activity relationships of nitroaromatics toxicity to the algae ( Scenedesmus obliguus)

The DFT-B3LYP method, with the basis set 6-311G ∗∗, was employed to calculate the molecular geometries and electronic structures of 25 nitroaromatics. The acute toxicity (−lg EC 50) of these compounds to the algae ( Scenedesmus obliguus) along with hydrophobicity described by log K OW, and two quantum chemical parameters-energy of the lowest unoccupied molecular orbital, E LUMO, and the charge of the nitro group, Q NO 2 , were used to establish the quantitative structure–activity relationships (QSARs). For 18 mononitro derivatives, the hydrophobicity parameter log K OW could interpret the toxic mechanism successfully. Dinitro aromatic compounds were susceptible to be reduced to aniline for their electrophilic nature. Their toxicity was controlled mainly by electronic factors instead of hydrophobicity. The electronic parameters, E LUMO and Q NO 2 , were used to yield the following model: - lg EC 50 = 3.746 - 25.053 E LUMO + 6.481 Q NO 2 ( n = 22, R = 0.926, SE = 0.206, F = 56.854, P < 0.001). The predicted toxic values using the above equation are in good agreement with the experimental values.

A Convenient, Efficient, and Environmentally Benign Method for Preparing Nitroanilines.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Condensation Monomers and Polymers Based on 2,4,6‐Trinitrotoluene

AbstractFor Abstract see ChemInform Abstract in Full Text.

A Convenient, Efficient, and Environmentally Benign Method for Preparing Nitroanilines

Abstract An efficient method for the catalytic monoreduction of aromatic dinitro compounds to nitroanilines is reported. In the presence of selenium catalyst, the dinitroaromatic compounds are selectively reduced by CO/H2O to the corresponding nitroanilines under atmospheric pressure. The mono-reduction occurs in high selectivity regardless of the substitution groups on the aromatic ring without affecting other reducible functional groups.

High-pressure ion source combined with an in-axis ion trap mass spectrometer. 2. Application of selective low-pressure negative ion chemical ionization

Negative ion chemical ionization was carried out using a quadrupole ion trap mass spectrometer with selected reactant negative ions, primarily injected from a homemade dual EI/CI external ion source. Hence, selective ion/molecule reactions were provided according to the reaction time, which induce a greater control over bimolecular ionization mechanisms than in conventional a high-pressure ion source combined with beam instruments, where several competitive ionization processes take place mainly due to source conditions (e.g., temperature, pressure, and repeller). By selecting the reactant ions, ion/molecule reactions were specifically produced (i.e., charge exchange, proton transfer, nucleophilic substitution, and/or alpha-beta elimination) with several organic target compounds. Gas-phase reactivity of phosphorus- and nitrogen-containing compounds (such as phosphonates as representative for chemical warfare agents and phosphorothionates, phosphorodithionates, and triazines for pesticides) as well as dinitro aromatic compounds (for pesticides) has been explored, in the present work, to ensure further unambiguous detection.