Aniline Research Articles

Coenzyme Q10 and N-acetyl cysteine modulates the haematological parameters, markers of oxidative stress and membrane bound phosphatase in spleen toxicity induced by aniline hydrochloride

Aniline is widely used chemical for industrial purpose. Exposure to aniline can lead to various health issues in human being. The most common toxic effect of aniline is splenotoxicity which is produced via the generation of oxidative stress. The present study examines the protective effect of coenzyme Q10 and N-acetyl cysteine on spleen weight, body weight, endogenous antioxidants and membrane bound ATPases in aniline hydrochloride (AH) induced spleen toxicity in rats. Adult male albino rats were divided into five groups, each group consists of six rats. Toxicity was induced by administration of AH (100 ppm, p. o) in drinking water for 30 days. Body weight, markers of oxidative stress and haematological parameters were assessed at the end of treatment period. Treatment rats received Coenzyme Q10 (CoQ10, 10 mg/kg/day/p.o) and N- acetyl cysteine (NAC, 300mg/kg/ day p.o) alone and in combination for 30. AH toxic rats showed a significant elevation of spleen weight, WBC count, iron content, LPO level, NO level and Ca ATPase whereas a significant decrease in body weight, haemoglobin, RBCs level, Protein content, GSH and Na/ K and Mg ATPase were observed. Administration of Coenzyme Q10 (CoQ10, 10 mg/kg/day/p.o) and N- acetyl cysteine (NAC, 300mg/kg/ day p.o) together for 30 consecutive days shows a significant decrease in spleen weight, WBC level, iron content, LPO level, NO level whereas significant increase in body weight, hemoglobin level, RBCs level Protein content, GSH level, Na/ K ATPase, Ca and Mg ATPase when compared with aniline treated group and CoQ10 or NAC alone treated groups. These findings indicate the synergistic & protective effect of CoQ10 and NAC in aniline induced spleen toxicity in rats compared to alone antioxidants.

Amphiphilic Grafted Polymers Based on Citric Acid and Aniline Used to Enhance the Antifouling and Permeability Properties of PES Membranes

Water treatment technology based on ultrafiltration (UF) faces the problem of severe membrane fouling due to its inherent hydrophobicity. The use of amphiphilic polymers that possess both hydrophobic and hydrophilic chain segments can be advantageous for the hydrophilic modification of UF membranes due to their excellent combination in the membrane matrix. In the present study, we examined a novel amphiphilic CA-g-AN material, constructed by grafting citric acid (CA) to aniline (AN), as a modified material to improve the hydrophilicity of a PES membrane. This material was more compatible with the polymer membrane matrix than a pure hydrophilic modified material. The polyethersulfone (PES) membranes modified by amphiphilic CA-g-AN demonstrated a higher water flux (290.13 L·m-2·h-1), which was more than eight times higher than that of the pure PES membrane. Furthermore, the flux recovery ratio (FRR) of the modified membrane could reach 83.24% and the value of the water contact angle (WCA) was 76.43°, demonstrating the enhanced hydrophilicity and antifouling ability of the modified membranes. With this study, we aimed to develop a new amphiphilic polymer to improve the antifouling property and permeability of polymer-based UF membranes to remove organic pollutants from water.

Bio-inspired hierarchical structure of polyaniline in the pore surface of polymer film through interfacial polymerization as a smart material sensitive to pH

The bio-inspired hierarchical structure of polyaniline (PANI) was fabricated in the pore surface of polymer film through interfacial polymerization. The porous polystyrene (PS) honey-comb patterned (HCP) film containing benzoyl peroxide (BPO) was first fabricated by the breath figure (BF) method under humid conditions, further, the film was immersed into aniline hydrochloride aqueous solution for the interfacial polymerization of PANI. The interfacial polymerization of the HCP porous film led to the biomimetic growth of PANI in fractal configuration for a bio-inspired snowflake or leaf-like pattern in the pore surface. The bio-inspired structure of PANI in the HCP porous film through interfacial polymerization is explained by the diffusion-leading aggregation (DLA) by the reaction of aniline monomer into an aqueous solution and self-assembled BPO in the pore surface. The morphology of the bio-inspired PANI structure in the HCP film was highly sensitive to pH, and revealed the conductivity variation over several orders of magnitude (10-3 to 10-1 S/cm) similar to a smart material. Due to the high pH sensitivity, the film can be applied in various biomedical sensing applications.

Mass spectrometry insight into the electro-copolymerization mechanism of aniline with o-phenylenediamine

It has been a challenge to accurately characterize the chain growth mechanism during copolymerization. Herein, an electrochemistry-microtube-mass spectrometry (EC-mTube-MS) was developed for on-line monitoring of aniline (ANI) electro-copolymerized with o-phenylenediamine (oPD). Short-lived intermediates and co-oligomers belonging to polyANI-oPD were structural identified with tandem MS method for the first time. The free binding between ANI and oPD monomers determined the presence of more species for a given co-n-mer. Chain growth was found to compete with 2H+, 2e− intramolecular oxidation of co-oligomers, resulting in the units with quinone or phenazine structures. MS signals for polyANI and polyoPD were observed as well, indicating that the homopolymerization occurred simultaneously with the copolymerization, which may affect the formation efficiency even performance of the final copolymer. Investigations on the monomer feed ratio and solution pH provided data support for improving the copolymerization efficiency, and the recommended parameters are cANI: coPD ≥ 10:1 and pH = 7.

Engineering Cytochrome P450BM3 Enzymes for Direct Nitration of Unsaturated Hydrocarbons

AbstractApplications of the peroxidase activity of cytochrome P450 enzymes in synthetic chemistry remain largely unexplored. We present herein a protein engineering strategy to increase cytochrome P450BM3 peroxidase activity for the direct nitration of aromatic compounds and terminal aryl‐substituted olefins in the presence of a dual‐functional small molecule (DFSM). Site‐directed mutations of key active‐site residues allowed the efficient regulation of steric effects to limit substrate access and, thus, a significant decrease in monooxygenation activity and increase in peroxidase activity. Nitration of several phenol and aniline compounds also yielded ortho‐ and para‐nitration products with moderate‐to‐high total turnover numbers. Besides direct aromatic nitration by P450 variants using nitrite as a nitrating agent, we also demonstrated the use of the DFSM‐facilitated P450 peroxidase system for the nitration of the vinyl group of styrene and its derivatives.

Engineering Cytochrome P450BM3 Enzymes for Direct Nitration of Unsaturated Hydrocarbons.

Applications of the peroxidase activity of cytochrome P450 enzymes in synthetic chemistry remain largely unexplored. We present herein a protein engineering strategy to increase cytochrome P450BM3 peroxidase activity for the direct nitration of aromatic compounds and terminal aryl-substituted olefins in the presence of a dual-functional small molecule (DFSM). Site-directed mutations of key active-site residues allowed the efficient regulation of steric effects to limit substrate access and, thus, a significant decrease in monooxygenation activity and increase in peroxidase activity. Nitration of several phenol and aniline compounds also yielded ortho- and para-nitration products with moderate-to-high total turnover numbers. Besides direct aromatic nitration by P450 variants using nitrite as a nitrating agent, we also demonstrated the use of the DFSM-facilitated P450 peroxidase system for the nitration of the vinyl group of styrene and its derivatives.

Coumarinacyl Anilinium Salt: A Versatile Visible and NIR Photoinitiator for Cationic and Step-Growth Polymerizations

A coumarinacyl anilinium (CAA) salt, facilely synthesized via a one-pot reaction, is shown to be a versatile visible and NIR photoinitiator for cationic and step-growth polymerizations. CAA salt exhibits superior photoinitiation performance as compared to commercial iodonium salt in cationic polymerization. Upon visible-light irradiation, this salt undergoes hemolytic and heterolytic cleavage and subsequent electron transfer and hydrogen abstraction reactions, forming reactive species capable of initiating cationic polymerization of epoxides and vinyl monomers. After a short irradiation period, polymerization also proceeds in the dark due to the non-nucleophilic nature of the counteranion. NIR-induced polymerizations were successfully conducted based on upconversion photochemistry. CAA salt can also initiate step-growth polymerization of N-ethyl carbazole (NEC) by oxidation of the monomer by the photochemically formed anilium radical cations. Subsequent proton release and radical coupling reactions essentially yield polycarbazole. CAA salt, featuring straightforward synthesis and long-wavelength sensitivity as well as versatile photoinitiating performance, has great potential in various applications.

Oxidative Addition of a Phosphinite P–O Bond at Nickel

Oxidative addition is an essential elementary reaction in organometallic chemistry and catalysis. While a diverse array of oxidative addition reactions has been reported to date, examples of P-O bond activation are surprisingly rare. Herein, we report the ligand-templated oxidative addition of a phosphinite P-O bond in the diphosphinito aniline compound HN(2-OPiPr2-3,5-tBu-C6H2)2 [H(P2ONO)] at Ni0 to form (PONO)Ni(HPiPr2) after proton rearrangement. Notably, the P-O cleavage occurs selectively over an amine N-H bond activation. Additionally, the ligand cannibalization is reversible, as addition of XPR2 (X = Cl, Br; R = iPr, Cy) to (PONO)Ni(HPiPr2) readily produces either symmetric or unsymmetric (P2ONO)NiX species and free HPiPr2. Finally, the mechanisms of both the initial P-O bond cleavage and its subsequent reconstruction are investigated to provide further insight into how to target P-O bond activation.

Selective Photocatalytic Reduction of Nitrobenzene to Aniline Using TiO2 Embedded in sPS Aerogel

In recent years, aromatic substances have become the focus of environmental pollution-related concern due to their high stability and mutagenicity. In this regard, researchers have focused their attention on the development of photocatalytic processes to convert nitroaromatic compounds into aniline. In this work, the photocatalytic conversion of nitrobenzene (NB) to aniline (AN) was studied. The photocatalytic reaction was performed using commercial TiO2 (P25) and a photocatalytic aerogel, based on P25 embedded in syndiotactic polystyrene (sPS) aerogel (sPS/P25 aerogel) as photocatalysts. Different alcohols were used as hydrogen sources during the photocatalytic experiments. At the optimized operating conditions (photocatalysts dosage: 0.5 mg/L and 50% (v/v) EtOH%), an AN yield of over 99% was achieved. According to the results, this work could open avenues toward effective production of AN from NB using mild reaction conditions with sPS/P25 aerogel-in view of a possible scale-up of the photocatalytic process.

Click reactions to prepare symmetrical and asymmetrical and broad-band near-infrared absorbing dyes

Aniline compounds, both symmetric and asymmetric, were prepared via click chemistry and Sonogashira coupling reactions, and the third-order nonlinear optical properties of these compounds were studied.

Fluorescent nano-sized aggregates of halogen bonded complexes formed using perfluoropropyl iodides: a systematic comparison between two isomeric halogen bond acceptors, aniline and 4-methyl pyridine.

The halogen bonds (XB) formed by the two isomers 4-methyl pyridine (MePy) and aniline (ANL) with heptafluoro-1-propyl iodide (n-C3F7I) and heptafluoro-2-propyl iodide (iso-C3F7I) were investigated using vibrational (FT-IR and Raman) spectroscopy and quantum mechanical calculations. While these two isomers indicated a distinctive impact on the ring related vibrations, molecular electrostatic potential, frontier molecular orbitals, intermolecular electron density delocalisation and consequential charge transfer upon halogen bonding with n-C3F7I and iso-C3F7I, the dramatic intermolecular charge transfer (CT) occurring on the MePy involved XB systems demonstrated an ion-pair like aggregation. Such aggregation, after 72 h and longer after mixing, leads to an emission of fluorescence for both [MePy·C3F7I] systems. The resulting nano-sized aggregates were characterised using UV-Vis absorption and fluorescence spectroscopy along with scanning and transmittance electron microscopy (SEM and TEM), wherein, the XB complex with iso-C3F7I showed a faster and more severe aggregation due to a stronger CT than that with n-C3F7I. The present work is the first case of aggregation induced emission (AIE) due to aggregation of XB complexes formed by small neutral molecules.

A Ti3C2Tx@PANI core-shell heterostructure assembled into a 3D porous hydrogel as a free-standing electrode for high-energy supercapacitors.

Although Ti3C2Tx MXenes have attracted attention in electrochemical energy storage devices due to their excellent electronic conductivity, controllable layer structure, and huge redox active surface area, the application of Ti3C2Tx as supercapacitor (SC) electrode materials is severely limited by the ineffective chemical ion transport kinetics caused by self-restacking. In order to increase the interlayer spacing of Ti3C2Tx, the intercalation method is hailed as an effective process. Herein, polyaniline (PANI) nanorods as intercalators were synthesized by the polymerization of an aniline (ANI) monomer chemisorbed onto Ti3C2Tx wrinkled nanosheets, and the formation of a Ti3C2Tx@PANI heterostructure is conducive to the large interlayer voids. Then, the heterostructure was integrated into a three-dimensional (3D) porous cross-linked framework via a simple graphene oxide (GO)-assisted self-convergence hydrothermal strategy with low temperatures. Due to the synergistic effect among each component and 3D porous interconnected structure, the hierarchical Ti3C2Tx@PANI-reduced graphene oxide (RGO) heterostructure hydrogel possesses the advantages of excellent electrical conductivity, high specific capacitance, repressive aggregation, and large electrochemical active area. Heterostructure hydrogel electrodes (without binders) display excellent electrochemical performance with a specific capacitance as high as 301.0 F g-1 at 1 A g-1, 90.74% capacitance retention over 10 000 cycles, and a maximum energy density of 44.6 W h kg-1 at a power density of 504.7 W kg-1. Our study provides a fresh strategy for constructing a 3D Ti3C2Tx-based framework applicable to other MXenes in the design of hybrid structures for maximizing their potential applications in energy storage.

Cationic tetranuclear macrocyclic CaCo3 complexes as highly active catalysts for alternating copolymerization of propylene oxide and carbon dioxide.

We found that a cationic hetero tetranuclear complex including a calcium and three cobalts exhibited high catalytic activity toward alternating copolymerization of propylene oxide (PO) and carbon dioxide (CO2). The tertiary anilinium salt [PhNMe2H][B(C6F5)4] was the best additive to generate the cationic species while maintaining polymer selectivity and carbonate linkage, even under 1.0 MPa CO2. Density functional theory calculations clarified that the reaction pathway mediated by the cationic complex is more favorable than that mediated by the neutral complex by 1.0 kcal mol-1. We further found that the flexible ligand exchange between Ca and Co ions is important for the alternating copolymerization to proceed smoothly.

Quantitation of polyetheramines as the active components of detergent additives in gasoline by the ninhydrin reaction

The detergent additives added into gasoline can effectively reduce the accumulation of coke deposits in engine and improve the exhaust emission pollution. The cleaning effect of detergent additives depends on the contents and compositions of the active components which usually contain a terminal amino group. In this work, a quantitative method was established to determine the polyetheramines of detergent additives in gasoline by the ninhydrin reaction. Unlike the small molecule compounds containing amino groups, such as amino acids and alkylamines, the formation of vesicles significantly increased the reactivity between polyetheramines and ninhydrin. The ninhydrin reaction was prohibited when the vesicles of polyetheramines were destroyed by adding ethanol, which was confirmed by the mass spectrometry and dynamic light scattering results. At the optimized condition, the reaction between the polyetheramines and ninhydrin generated a blue-purple dye (Ruhemann’s purple) with a strong absorption at 560 nm. This reaction was highly selective, sensitive, and rapid. This quantitative method could distinguish the active components (polyetheramines) from the carrier oils (polyethers) in detergent additives. Aniline compounds in gasoline also did not interfere with the measurement of polyetheramines. The quantitative range was between 50 and 1000 mg/kg. The whole procedure could be finished in about 30 min. The accuracy of this method was verified using four different commercial polyetheramines and the results showed that the method was applicable to different types of detergent additives with relative errors lower than 10 %.

Au@Pt nanoparticles modified classical CdS nanorods for synergistically utilizing photoexcited charges in coupled selective organic transformations

The photocatalyst construction determines the cost and photoexcited charge kinetics, whereas reaction system design ensures the synergic utilization of photoexcited charges. Herein, a novel Au13@Pt/CdS hybrid nanomaterial was prepared and used for the coupling selective redox system of aromatic alcohols and nitroarenes. The Au13@Pt nanoparticles evenly and tightly anchored on CdS provided abundant e– enrichment sites and wider charge transfer channels and largely improved photocatalytic performance. After 4 h visible-light illumination (λ > 420 nm), the optimal 0.00115 % Au13@Pt/CdS sample displays that the theoretical yields of aniline (AL) and p-methoxybenzaldehyde (p-MBA) are up to 71.5 % and 94.7 % with an impressive selectivity of over 95 %, therefore, parts of the generated AL and p-MBA further formed Schiff base with a 24.3 % yield. Therefore, this work is expected to offer a way to fabricate a dual-functional photocatalyst for selective organic transformations (P-SOTs). A coupling mechanism of simultaneous SO p-MBA and SR of NB in one system was proposed by a series of physical and chemical characterizations combined with in suit DRIFTS and theoretical calculations.

Mechanochemical Synthesis of Polyanilines and Their Nanocomposites: A Critical Review.

The mechanochemical synthesis of polyanilines (PANIs), made by oxidative polymerization of anilines, is reviewed. First, previous knowledge of the polymerization reaction in solution is discussed to understand the effect of different parameters: oxidant/monomer ratio, added acid, oxidant, temperature and water content on the properties of the conducting polymers (molecular weight, degradation, doping/oxidation level, conductivity, and nanostructure). The work on mechanochemical polymerization (MCP) of anilines is analyzed in view of previous data in solution, and published data are critically reconsidered to clarify the interpretation of experimental results. A key factor is the production of acids during polymerization, which is often overlooked. The production of gaseous HCl during MCP of aniline hydrochloride is experimentally observed. Since some experiments involves the addition of small amounts of water, the kinetics and heat balance of the reaction with concentrated solutions were simulated. A simple experiment shows fast (<2 min) heating of the reaction mixture to the boiling point of water and temperature increments are observed during MCP in a mortar. The form and sizes of PANI nanostructures made by MCP or solution are compared. The extensive work on the production of nanocomposites by MCP of anilines together with different nanomaterials (porous clays, graphene, carbon nanotubes, metal, and oxide nanoparticles) is also described.

An efficient visible-light-driven photoconversion of nitrobenzene to aniline over PtO-decorated WO3 nanocrystals prepared by a soft template-based method

BackgroundPhotocatalysis represent a green method for oxidation and reduction reactions. This method is initiated by exciting a semiconducting material by light resulting in electron-hole (e‒‒h+) pair formation that contributes to chemical reactions. Using metal oxide photocatalysts is a green approach for selective organic transformation. Aniline (AN) is a joint compound in several chemical industries. MethodsThis work presents a simple soft template-assisted synthesis of tungsten oxide (WO3) nanocrystals followed by adding trace amounts (0.1‒0.4 wt.%) of platinum oxide (PtO) nanodots through precipitation. Significant findingsPhysicochemical description of formed heterostructures unveiled the mesoporous surface texture construction and the significance of PtO inclusion on the optical and semiconducting properties of WO3. The PtO addition to WO3 at 0.3 wt.% confirms the considerable decrease of the bandgap energy from 2.74 to 2.36 eV, revealing the excellent visible light fascination. The PtO-decorated WO3 was performed to synthesize AN from NB by photoconversion. The optimal dose of 0.3% PtO/WO3 (2.0 gL–1) revealed a complete photoconversion of NB into the beneficial AN within 40 min with magnificent reusability. The PtO loading demonstrates the enhanced e‒‒h+ separation and mobilities. This study opens the door for plenty of research toward the realization of metal oxide-based heterostructures to produce industrial chemicals.

Dual functions of activated carbon air‐cathode: Nitrobenzene removal and electricity production in microbial fuel cells

AbstractThe removal of nitrobenzene (NB) in microbial electrochemical systems generally requires electrical power to operate systems in the mode of microbial electrolysis cells (MECs). The present study demonstrates that single‐chamber microbial fuel cells (S‐MFCs) assembled with a bioanode and an activated carbon (AC) air cathode could simultaneously remove NB and generate electricity. S‐MFCs with 1 mM NB exhibit long term NB tolerance and stable electricity production, with NB removal up to 98% in an operation cycle and a maximum power of 16.2 ± 1.3 W m−3. High NB loadings significantly inhibited the activity of anodic biofilms, but the inhibition was reversible. Investigating the removal of NB and its reduction product aniline (AN) in different operations supported the fact that the adsorption at the AC air cathode is the main pathway for the removal of NB and AN from solution, except for the partial conversion of NB to AN by anaerobic reduction in solution. In S‐MFCs, the activated carbon in the cathode plays both functions: catalyzing the oxygen reduction reaction and adsorbing NB and AN, so that the S‐MFC assembled with the AC air cathode, unlike most NB removing MECs, functions as a system with both NB removal and electricity production.

Spectral, Thermal Behavior, Molecular Modeling, and Antimicrobial Studies of Fuchsin Basic Hydrochloride

AbstractThe current study reported important characteristic features of the 4‐[(4‐aminophenyl)‐(4‐imino‐3‐methylcyclohexa‐2,5‐dien‐1‐ylidene)methyl]aniline hydrochloride known as fuchsin basic dye (FB). The thermal decomposition behavior of the dye was scrutinized through thermogravimetric analysis (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). Besides, the acid dissociation constants of FB were evaluated by analyzing its electronic spectra at different pH values. In addition, a docking study was also carried out to investigate the binding affinity between the FB dye and two selected proteins (3t88 and 1bqb) of Escherichia coli and Staphylococcus aureus, respectively. The docked complex of the dye with the target proteins exhibits moderate scoring energy values (−5.2025 and −5.5762 kcal/mol where the receptors are bonded to the dye through H‐bonds of lengths that are less than 3.5 Å. The dye was also tested for its antimicrobial activity against two Gram‐positive and two Gram‐negative bacterial species. The results revealed moderate to good activity against Klebsiella pneumonia, Escherichia coli, and Streptococcus pyogenes species compared to amoxicillin 0.1 % as a reference control.

Effective removal of 2,4-dichlorophenoxyacetic acid from aqueous solutions using polyaniline recovered from non-recyclable pigment effluent via electro polymerization

Electro conducting polymer - polyaniline is used as a pigment in the epoxy based coating system. These pigment developing industries releases unreactive monomers and dimers of aniline compound (byproducts of chemical polymerization) in the effluent which creates environmental issues. The present study focuses on the recovery of polyaniline from the pigment effluent by electrochemical polymerization method. The aniline monomers were polymerized on the graphite plate as emeraldine base form at an anode potential of 0.6 to 0.68 V with simultaneous decrease in its monomer concentration. The recovered polyaniline (PANI) exhibited smooth rod shape morphology and displayed (011), (020) and (200) crystal planes for the emeraldine base form in X-ray diffraction studies. The recovered PANI was subjected to carbonization and activation (PANI-AC) for its application in adsorptive removal of 2,4-dichlorophenoxyacetic acid (2,4-D) removal. The PANI-AC outperformed commercial activated carbon in removing 50 ppm of 2,4-D from water matrix. The 25 ppm of PANI-AC adsorbent was able to remove 100 %, 85 %, 57 % and 29 % of 100 μg L−1, 250 μg L−1, 500 μg L−1 and 1000 μg L−1 of 2,4-D respectively. The 2,4-D adsorptive removal followed a pseudo second order kinetic model and obeyed Langmuir and Freundlich isotherms. The maximum adsorption capacity of the PANI-AC is of 34.48 mg g−1 (Langmuir isotherm). These findings direct the possible recovery of polyaniline form pigment effluent of paint industries and its application as adsorbent in efficient removal of 2,4-D from aqueous matrix.