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Solvent extraction behaviors of Se (VI) from nitric acid solutions were investigated with multiple extractants used for uranium, plutonium, minor actinides, and rare earth elements separation processes from high-level liquid waste. During the processes, Se remained in the residual aqueous solutions, as all extractants showed distribution ratios < 1. In contrast, Se showed distribution ratios > 1 with o-phenylenediamine in dilute nitric acid (< 2 M HNO3), octanol as the organic phase, and concentrated nitric acid (8 M HNO3) for back extraction, suggesting a potential new single separation process and recovery of Se. [ABSTRACT FROM AUTHOR]

A porous structure of copolymer poly (aniline-co–o-phenylenediamine) has been fabricated by chemical oxidation process with nonionic surfactant Triton X-100. Different ratios of monomers (1:9, 5:5 and 9:1) have been utilized; structure and surface morphology has been analyzed by FTIR and SEM–EDX techniques. The UV, XRD and BET surface area measurement were also done. The electrochemical techniques such as cyclic voltammetry and electrochemical impedance were used to evaluate electrochemical capacitance performances. The copolymer comprising equimolar mixture of monomers displayed high surface area that helps to amplify the diffusion of electrolyte ions. Hence, the specific capacitance of developed copolymer has been determined as 989 F g−1 at 5 mA cm−2 current density from galvanostatic charge–discharge studies with retainability of 84.94% capacitance after 100 cycles. [ABSTRACT FROM AUTHOR]

π‐Conjugated polyfluorenes (PPs) comprising 2,3‐diaminobenzene‐1,4‐diyl (unit A) and 9,9‐dihexylfluorene‐2,7‐diyl (polymer‐1) or 9,9‐bis(6‐N,N,N,‐trimethylammoniumhexyl)fluorene‐2,7‐diyl (unit B) (polymer‐2) units were synthesized using Suzuki‐Miyaura coupling polycondensation. To compare the chemical properties and functionality of polymer‐2, a water‐soluble PP comprising benzene‐1,4‐diyl and unit B (polymer‐3) was synthesized. Polymer‐1 exhibited solvatochromism: the photoluminescence (PL) peak of the polymer in solutions shifted to a longer wavelength with an increase in the dielectric constants of solvents. Polymer‐1 formed charge transfer (CT) complexes with organic electron acceptors. The CT complexation behavior was systematically elucidated by the PL measurements using Stern–Volmer and Benesi–Hildebrand methods. Water‐soluble polymer‐2 could be used as a sensor for the chain length of telomere DNA by monitoring the changes in its PL intensity upon the addition of the analyte. The DNA sensing performance of polymer‐2 surpassed that of polymer‐3, attributed to the presence of unit A in polymer‐2. This unit brought polymer‐2 closer to DNA through hydrogen bonding between the amino group of polymer‐2 and nucleic acids in DNA. This interaction facilitated the occurrence of CT from the polymer backbone to DNA. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An effective, green and eco-friendly method was developed to synthesize 1H-benzimidazole under microwave irradiation. The reactions of substituted o-phenylenediamine with DMF were efficiently promoted by butanoic acid, and the desired product 1H-benzimidazole derivatives were obtained in good to excellent yields. Compared with the conventional heating method, microwave irradiation significantly reduced the reaction time and improved the yields of the target products. [ABSTRACT FROM AUTHOR]

In heterocyclic chemistry, benzimidazole is recognized as a "privileged structure" due to its association with a wide range of biological activities. In this present research work, we included the synthesis, characterization and biological evaluation of substituted derivatives. The designated derivatives were synthesized by the condensation method. ortho-Phenylenediamine was used as the starting material. The designated benzimidazole derivatives were synthesized using different acids and aldehydes. Further, the in-vitro antifungal-activity-synthesized compounds were evaluated against Candida albicans using the agar well diffusion method and the culture tube method. It was concluded that all the designated derivatives of benzimidazole exhibited prominent antifungal activity and can be considered as potent leads in future antifungal research. [ABSTRACT FROM AUTHOR]

With the expansion of human activities, the consequent influx of mercury (Hg) into the food chain and the environment is seriously threatening human life. Herein, nitrogen and sulfur co-doped fluorescent carbon quantum dots (yCQDs) were prepared via a hydrothermal method using o-phenylenediamine (OPD) and taurine as precursors. The morphological characteristics as well as spectral features of yCQDs indicated that the photoluminescence mechanism should be the molecular state fluorophores of 2, 3-diaminophenothiazine (oxOPD), which is the oxide of OPD. The as-synthesized yCQDs exhibited sensitive recognition of Hg2+. According to the investigation in combination of UV-Vis absorption spectra, time-resolved fluorescence spectra and quantum chemical calculations, the abundant functional groups on the surface of yCQDs allowed Hg2+ to bind with yCQDs through various interactions, and the formed complexes significantly inhibited the absorption of excitation light, resulting in the static fluorescence quenching of yCQDs. The proposed yCQDs was utilized for Hg2+ sensing with the limit of detection calculated to be 4.50 × 10− 8 M. Furthermore, the recognition ability of yCQDs for Hg2+ was estimated in tap water, lake water and bottled water, and the results indicated that yCQDs have potential applications in monitoring Hg2+. [ABSTRACT FROM AUTHOR]

A novel o-phenylenediamine (opda)-based cadmium complex, bis(benzene-1,2-diamine-κ2N,N′)bis(benzene-1,2-diamine-κN)cadmium(II) naphthalene-1,5-disulfonate, [Cd(C6H8N2)4](C10H6O6S2), was synthesized. The complex salt crystallizes in the monoclinic space group C2/c. The Cd atom occupies a special position and coordinates six nitrogen atoms from four o-phenylenediamine molecules, two as chelating ligands and two as monodentate ligands. The amino H atoms of opda interact with two O atoms of the naphthalene-1,5-disulfonate anions. The anions act as bridges between [Cd(opda)4]2+ cations, forming a two-dimensional network in the [010] and [001] directions. The Hirshfeld surface analysis shows that the primary factors contributing to the supramolecular interactions are short contacts, particularly van der Waals forces of the type H...H, O...H and C...H.

Normalizing inflamed soils including reactive oxygen species (ROS), nitric oxide (NO), cell-free DNA, and regulating inflammation-related seeds such as macrophages, neutrophils, fibroblasts, represent a promising strategy to maintain synovial tissue homeostasis for rheumatoid arthritis (RA) treatment. Herein, ROS scavenging amphiphilic block copolymer PEGylated bilirubin and NO-scavenging PEGylated o-phenylenediamine were fabricated to self-assemble into a dually responsive nanoparticle loaded with JAK inhibitor notopterol (Not@BR/oPDA-PEG, NBOP NPs). The simultaneous ROS and NO depletion combined with JAK-STAT pathway inhibition could not only promote M2 polarization to reduce further ROS and NO generation, but also decrease cytokines and chemokines to prevent immune cell recruitment. Specifically, NBOP NPs responded to high level ROS and NO, and disintegrated to release notopterol in inflamed joints as the hydrophobic heads BR and oPDA were transformed into hydrophilic ones. The released notopterol could inhibit the JAK-STAT pathway of inflammatory cells to reduce the secretion of pro-inflammatory cytokines and chemokines. This strategy represented an effective way to regulate RA soils and seeds through breaking the positive feedback loop of inflammation aggravation, achieving an excellent anti-RA efficacy in a collagen-induced arthritis rat model. Taken together, our work offered a reference to adjust RA soils and seeds for enhanced RA treatment.

Conjugated polymers (CPs) having a backbone of alternating single and multiple bonds are well known for their technological applications. Herein, we report the successful synthesis of CPs; poly(o-chloroaniline) (POCA), poly(o-phenylenediamine) (POPD), and for the first time their copolymer poly(OPD-co-OCA) along with the evaluation of corrosion inhibition efficiency. The obtained materials were characterized by UV–Visible spectroscopy, FTIR, SEM, XRD, TGA, and cyclic voltammetry measurements. The comparative analysis confirmed the satisfactory formation of homopolymers POCA, POPD and its copolymer poly(OPD-co-OCA). The homopolymer POPD and copolymer poly(OPD-co-OCA) are soluble in common organic solvents (acetone, methanol, N-methyl-2-pyrrolidone (NMP), Dimethyl sulfoxide (DMSO), and chloroform) while homopolymer POCA is insoluble. The novel copolymer poly(OPD-co-OCA) reveals good thermal stability than homopolymers POPD and POCA. The cyclic voltammetry studies show that copolymer poly(OPD-co-OCA) acquired redox behavior having an anodic peak at about 0.4 V, nevertheless corresponding homopolymer POPD act as an insulator with no obvious redox peak. The corrosion inhibition efficiency on a mild steel for copolymer poly(OPD-co-OCA) is found 70 to 80% which is reasonably higher than homopolymer POPD (68%), probably is due to donor–acceptor substituents involved in copolymer. [ABSTRACT FROM AUTHOR]

A one-pot, two-step, four-component synthesis of novel benzo[a]phenazin-5-ol derivatives was carried out by the condensation-Michael addition reactions of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, aromatic aldehydes, and 4-hydroxycoumarine in glacial acetic acid under reflux conditions. The notable features of this domino protocol are simple experimental procedure, readily available starting materials, metal-free reaction condition, clean reaction profile, good to high yields of the products, absence of any tedious workup and easy isolation of pure products without chromatography. [ABSTRACT FROM AUTHOR]

Background. The use of new drugs with high bioactivity in agriculture is relevant. One of them is the combination of o-phenylenediamine with a ligand that has potential biological activity. Purpose: Preparation of a mixed-ligand complex compound of o-phenylenediamine and 2,4- dihydroxybenzoic acid with Ni(II), study of synthesis conditions, determination of the crystal structure and physicochemical properties. Methodology. X-ray diffraction analysis (XRD) and IR spectroscopy (Xcalibur R Oxford Diffraction and IRAffinity-1S IR spectrometer) were used. Originality. For the first time, a mixed-ligand complex of o-phenylenediamine with Ni(II) was synthesized and the crystal structure was studied, Hirschfeld surface analysis and physicochemical properties of the synthesized complex were performed. Findings. A compound consisting of o-phenylenediamine, 2,4-dihydroxybenzoic acid and [(Ni(C6H8N2)2(C7H6O4)2)] was synthesized and its properties were studied. [ABSTRACT FROM AUTHOR]

A novel o-phenyl­enedi­amine (opda)-based cadmium complex, bis­(benzene-1,2-di­amine-κ²N,N′)bis­(benzene-1,2-di­amine-κN)cadmium(II) naphthalene-1,5-di­sulfonate, [Cd(C6H8N2)4](C10H6O6S2), was synthesized. The complex salt crystallizes in the monoclinic space group C2/c. The Cd atom occupies a special position and coordinates six nitro­gen atoms from four o-phenyl­enedi­amine mol­ecules, two as chelating ligands and two as monodentate ligands. The amino H atoms of opda inter­act with two O atoms of the naphthalene-1,5-di­sulfonate anions. The anions act as bridges between [Cd(opda)4]2+ cations, forming a two-dimensional network in the [010] and [001] directions. The Hirshfeld surface analysis shows that the primary factors contributing to the supramolecular inter­actions are short contacts, particularly van der Waals forces of the type HH, OH and CH. [ABSTRACT FROM AUTHOR]

Normalizing inflamed soils including reactive oxygen species (ROS), nitric oxide (NO), cell-free DNA, and regulating inflammation-related seeds such as macrophages, neutrophils, fibroblasts, represent a promising strategy to maintain synovial tissue homeostasis for rheumatoid arthritis (RA) treatment. Herein, ROS scavenging amphiphilic block copolymer PEGylated bilirubin and NO-scavenging PEGylated o -phenylenediamine were fabricated to self-assemble into a dually responsive nanoparticle loaded with JAK inhibitor notopterol (Not@BR/oPDA-PEG, NBOP NPs). The simultaneous ROS and NO depletion combined with JAK-STAT pathway inhibition could not only promote M2 polarization to reduce further ROS and NO generation, but also decrease cytokines and chemokines to prevent immune cell recruitment. Specifically, NBOP NPs responded to high level ROS and NO, and disintegrated to release notopterol in inflamed joints as the hydrophobic heads BR and oPDA were transformed into hydrophilic ones. The released notopterol could inhibit the JAK-STAT pathway of inflammatory cells to reduce the secretion of pro-inflammatory cytokines and chemokines. This strategy represented an effective way to regulate RA soils and seeds through breaking the positive feedback loop of inflammation aggravation, achieving an excellent anti-RA efficacy in a collagen-induced arthritis rat model. Taken together, our work offered a reference to adjust RA soils and seeds for enhanced RA treatment. A dually responsive nanoparticle loaded with JAK inhibitor notopterol (Not@BR/ o PDA-PEG, NBOP NPs) exhibited anti-arthritis efficacy based on reactive oxygen species (ROS) and nitric oxide (NO) scavenging as well as JAK-STAT inhibition. [Display omitted] [ABSTRACT FROM AUTHOR]

This work was aimed at the development of a sensitive electrochemical detection method for oxycodone in water. Molecularly imprinted electrodes were formed by electro-polymerization process using o-phenylenediamine as a monomer. The electro-polymerization was performed on glassy carbon electrodes in the presence of oxycodone before the extraction of entrapped oxycodone molecules. Various electrochemical techniques were employed to monitor the polymerization and response of the fabricated electrodes toward oxycodone. These techniques included cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The oxycodone concentration was determined using SWV by measuring the change in the oxidation peak current of [Fe(CN)6]3−/4− in a 0.1 mM acetate buffer solution. At the optimal electro-polymerization conditions, a calibration curve of the current versus the concentration of oxycodone indicated a linear response at a region from 0.4 nM to 5.0 nM with a detection limit of 1.8 ± 0.239 nM. The MIP-modified electrode's binding isotherm was fitted using a Langmuir model and showed an association constant, KA, of 1.12 × 106, indicating a high affinity of oxycodone molecules to binding sites. This sensor has the potential to act as an alternative method suitable for the on-site analysis of oxycodone. [ABSTRACT FROM AUTHOR]

The reaction of o-phenylenediamine (OPD), sodium naphthalene1,5-disulfonate (Na2NDS) and nickel sulfate in an ethanol–water mixture yielded the title compound, [Ni(OPD)2(H2O)2]·NDS or [Ni(C6H8N2)2(H2O)2](C10H6O6S2). This salt consists of a complex [Ni(OPD)2(H2O)2]2+ cation with two bidentate OPD ligands and trans aqua ligands, and a non-coordinating NDS2– anion, which is the double-deprotonated form of H2NDS. The NiII atom is situated at a center of inversion and exhibits a slightly tetragonally distorted {O2N4} octahedral coordination environment, with four shorter equatorial Ni—N bonds [2.0775 (17) and 2.0924 (18) Å] and a longer axial Ni—O bond [2.1381 (17) Å]. The OPD ligand is located about an inversion center and is nearly coplanar with the NiN4 plane [dihedral angle 0.95 (9)°]. In the crystal, the cations and anions are connected by charge-assisted intermolecular N—H...O and O—H...O hydrogen-bonding interactions into the tri-periodic network structure. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (44.1%), O...H/H...O (34.3%), C...H/H...C (14.8%) C...C (6.5%) (involving the cations) and O...H/H...O (50%), H...H (25%), C...H/H...C (15.3%), C...C (8.2%) (involving the anions) interactions.

This work was aimed at the development of a sensitive electrochemical detection method for oxycodone in water. Molecularly imprinted electrodes were formed by electro-polymerization process using o-phenylenediamine as a monomer. The electro-polymerization was performed on glassy carbon electrodes in the presence of oxycodone before the extraction of entrapped oxycodone molecules. Various electrochemical techniques were employed to monitor the polymerization and response of the fabricated electrodes toward oxycodone. These techniques included cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The oxycodone concentration was determined using SWV by measuring the change in the oxidation peak current of [Fe(CN)6]3−/4− in a 0.1 mM acetate buffer solution. At the optimal electro-polymerization conditions, a calibration curve of the current versus the concentration of oxycodone indicated a linear response at a region from 0.4 nM to 5.0 nM with a detection limit of 1.8 ± 0.239 nM. The MIP-modified electrode’s binding isotherm was fitted using a Langmuir model and showed an association constant, KA, of 1.12 × 106, indicating a high affinity of oxycodone molecules to binding sites. This sensor has the potential to act as an alternative method suitable for the on-site analysis of oxycodone.

The structure of the title compound (4d), unexpectedly obtained in the reaction between o-phenylenediamine and 2-benzoylcyclohexanone instead of the target 3H-benzo[b][1,4]diazepine derivative 3d, was determined spectroscopically in solution and by a single-crystal X-ray diffraction (XRD) study. It involves two enantiomeric rotamers, called forms D and U, of which the structure was elucidated based on NMR spectra measured and predicted in DFT-GIAO calculations. An averaging of δCs for all tautomeric positions in the benzimidazole part of the 4d hydrate studied in wet (probably slightly acidic) CDCl3 unambiguously indicates tautomeric exchange in its imidazole unit. An XRD analysis of this material confirms the existence of only one tautomer in the solid phase. The non-covalent interactions forming between molecules of water and benzimidazole derivative are shorter than the sum of van der Waals radii and create an infinite-chain hydrogen bond motif along the b-axis. A possible mechanism for the observed cyclocondensation is also proposed.

Molecularly imprinted polymer (MIP)-based electrochemical sensors have always won the attention of researchers due to their predetermined selectivity and high mechanical and chemical stability. A MIP-based voltammetric sensor for the selective determination of the clinically significant molecule xanthine based on electropolymerisation of o-phenylenediamine (o–PD) in presence of xanthine on the glassy carbon electrode surface previously modified with a conducting layer of L-serine (MIP/p(L-ser)/GCE) is reported here. Numerous experimental parameters were optimized to avail maximum performance of the sensor and under these analytical constraints, the sensor was able to selectively quantify xanthine over the linear range 1.00 × 10−4 M–1.00 × 10−6 M with a detection limit of 5.47 × 10−7 M. The sensor showed excellent selectivity towards xanthine in presence of other probably coexisting species. Furthermore, studies to account for the repeatability, reproducibility, and stability of the sensor were carried out and its potential applicability was successfully verified in artificial physiological fluids and in real samples of commercially available tea and coffee powders. [ABSTRACT FROM AUTHOR]

The reaction of o-phenylenediamine (OPD), sodium naphthalene1,5-disulfonate (Na2NDS) and nickel sulfate in an ethanol--water mixture yielded the title compound, [Ni(OPD)2(H2O)2]⋅NDS or [Ni(C6H8N2)2(H2O)2](C10H6O6S2). This salt consists of a complex [Ni(OPD)2(H2O)2]2+ cation with two bidentate OPD ligands and trans aqua ligands, and a non-coordinating NDS2- anion, which is the double-deprotonated form of H2NDS. The NiII atom is situated at a center of inversion and exhibits a slightly tetragonally distorted {O2N4} octahedral coordination environment, with four shorter equatorial Ni--N bonds [2.0775 (17) and 2.0924 (18) Å] and a longer axial Ni--O bond [2.1381 (17) Å ]. The OPD ligand is located about an inversion center and is nearly coplanar with the NiN4 plane [dihedral angle 0.95 (9)°]. In the crystal, the cations and anions are connected by charge-assisted intermolecular N--H⋯O and O--H⋯O hydrogen-bonding interactions into the tri-periodic network structure. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (44.1%), O⋯H/H⋯O (34.3%), C⋯H/H⋯C (14.8%) C⋯C (6.5%) (involving the cations) and O⋯H/H⋯O (50%), H⋯H (25%), C⋯H/H⋯C (15.3%), C⋯C (8.2%) (involving the anions) interactions. [ABSTRACT FROM AUTHOR]

7-bis-indolo[2,3-b] quinoxaline derivatives have been synthesized through the condensation of o-phenylenediamine 4 with 1-long chain alkylindoline-2,3-diones 1-3 in refluxing xylene for 12 hours to lead to the corresponding 6-alkyl-6(H)-indolo[2,3-b]quinoxalines 5-7. Moreover, the condensation of 1,2-diaminocyclohexane with isatin derivatives 9-11 in refluxing methanol in the presence of acetic acid as catalyst affords 1,2,3,4- tetrahydro-indolo[2,3-b] quinoxalines 12-14. Finally, the condensation of o-phenylenediamine 4 with 1,4-(butane-1,4-diyl)- bis-indolin-2-one 16 in refluxing xylene for 24 hours leads to 1,4-bis-(6Hindolo[2,3-b]diyl-quinoxalin-6-yl) butane 17. The structures of all compounds obtained have been elucidated on the basis on ¹H NMR, 13C NMR spectroscopy and mass spectrometry. [ABSTRACT FROM AUTHOR]

The aim of this study was to design and characterize a candidate molecule of biological significance by synergistically combining the unique chemical properties, biocompatibility, and low toxicity of carbon quantum dots (CNDs) by the precursor molecule o-phenylenediamine (o-PDA), which is used to produce most chemotherapeutic agents, as a CNDs/o-PDA conjugate. Using citric acid (CA), surface-functional CNDs were synthesized by simple and rapid thermal pyrolysis for 2 h at 180 °C without using chemicals. Conjugation was carried out for 16 h at 40 °C in N,N-dimethylformamide (DMF) presence of triethylamine (Et3N). Structural characterizations were performed by spectroscopic techniques such as attenuated total reflectance—Fourier transform infrared (ATR-FTIR), nuclear magnetic resonance (1H-NMR), UV–Vis, and fluorescence spectroscopy. The crystal structure of pure- and o-PDA-conjugated-CNDs was characterized using X-ray diffractometers (XRD-MF). Physical characterizations were performed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Q-TOF LC/MS (liquid chromatography–quadrupole-time-of-flight mass spectrometry) and size exclusion chromatography (SEC) were used to analyze molecular weight change and polydispersity index (PDI) as a result of o-PDA conjugation. The spherical nanoparticle size of the nanodots was confirmed by transmission electron microscopy (TEM). All results suggest that the targeted o-PDA derivatization of CNDs was successfully achieved by the ring-opening reaction. [ABSTRACT FROM AUTHOR]

Objective: Construction of a simple and rapid method for the analysis of ganoderic acid A （GAA）. Methods: The molecular imprinted polymer （MIP） that can specifically recognize ganoderic acid A （GAA） were prepared by cyclic voltammetric deposition using GAA as template molecule and o-phenylenediamine as functional monomer. The structure, morphology and electrochemical behavior of MIP were characterized by infrared spectroscopy, scanning electron microscopy and electrochemical methods. Using [Fe（CN）6]3-/4- as the active indicator, the analytical performance of the sensor for GAA was investigated. Porous MIP for GAA can be prepared on the electrode surface by one-step electropolymerization. Results: The results of quantitative analysis showed that the electrochemical signal of [Fe（CN）6]3-/4- had a good linear relationship with the logarithm of GAA concentration in the range of 1.0 pmol/L～1.0 μmol/L, and the detection limit was 0.21 pmol/L. The measured values of GAA in ethanol and water-soluble solution of Ganoderma lucidum powder were 1.15 nmol/L and 3.00 pmol/L, respectively. Conclusion: The MIP-based GAA electrochemical sensor can be used for the rapid determination of GAA in extract solution of Ganoderma lucidum powder.

Core–shell nanocomposite of copper hexacyanoferrate copolymer of anthranilic acid with o-phenylenediamine (CHCF-poly-AA-co-OPD)) was synthesized and used as ion exchanger for the removal of cesium ions from wastewater. The nanocomposite was prepared by implantation of CHCF nanoparticles into the copolymer of poly(AA-co-OPD) during the polymerization process. By transmission electron microscope, scanning electron microscope and Brunauer–Emmett–Teller, the surface morphology and the porous structure were investigated. The physicochemical characterization of the prepared core–shell nanocomposite was carried out by FT-IR spectroscopy, XRD and thermogravimetric analysis. As a function in pH, metal ion concentration, shaking time and temperature, the capacity of the CSNC toward cesium ions and the behaviors of the process were studied. The results illustrated that the maximum capacity was recorded 1.35 mmol g−1 at pH 11, 10 mmol L−1 Cs+ and 25 °C. Also, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) isotherms models were studied, in which the data were well fitted with Langmuir model, suggesting that the uptake of Cs+ was monolayer and homogeneous. Also, the adsorption kinetics data were fitted well to pseudo-second-order model. Thermodynamic parameters were calculated in the temperature from 25 to 60 °C, and the data revealed that Cs+ sorption was endothermic, spontaneous and more favorable at higher temperature. Up to 92% desorption of Cs+ was completed with 2 M KCl. [ABSTRACT FROM AUTHOR]

Esters of (het)aroylpyruvic acids can react with o-phenylenediamine, leading to the formation of (Z)-3-(2-(het)aryl-2-oxoethylidene)-3,4-dihydroquinoxalin-2(1H)-ones and 4-(het)aryl-3H-1,5-benzodiazepine-2-carboxylates. The obtained product ratio depends on the electronic effects due to substituents in the (het)aroyl moiety of (het)aroylpyruvate esters and the reaction conditions. The highest ratio of quinoxalinones relevant for medicinal chemistry was observed when using (het)aroylpyruvate esters without substituents that would cause a negative mesomeric effect in the (het)aroyl moiety, as well as when performing the reactions in acetic acid. [ABSTRACT FROM AUTHOR]

2-Aminobenzylaniline was ditosylated and gave an unexpected product N,N-ditosylamino-2-benzylaminobenzene in which the primary amine had ditosylated, and the benzylamine was unreacted. The benzylamine, although more electron rich, is sterically crowded and less nucleophilic than the primary amine in this ditosylated system. Sterically crowded tosylamides were prepared by reacting o-phenylenediamine, p-phenylenediamine and 1,8-diaminonaphthalene with tosyl chloride. [ABSTRACT FROM AUTHOR]

The random lamellae of the synthetic CP were synthesized with a hydrothermal approach using o-Phenylenediamine (OPD) as a modifier. The decreases in the order degree of the CP synthesized in the presence of the OPD resulted from the loss of long-range order in a certain direction. Subsequently, the ultrasonic treatment and washing were conducive to further facilitate the disordered arrangements of its lamellae. The possible promotion mechanism regarding the nucleation and growth behaviors of the sol-gel particles was proposed. The fractal evolutions of the aluminosilicate species with crystallization time implied that the aluminosilicate species became gradually smooth to rough during the crystallization procedures since the amorphous structures transformed into flower-like morphologies. Their gas adsorption and separation performances indicated that the adsorption capacity of CO2 at 273 K reached up to 2.14 mmol·g−1 at 1 bar, and the selective factor (CO2/CH4) up to 3.4, much higher than that of the CPs synthesized without additive OPD. The breakthrough experiments displayed a longer breakthrough time and enhancement of CO2 uptake, showing better performance for CO2/CH4 separation. The cycling test further highlighted their efficiency for CO2/CH4 separation. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tyrosinase is an enzyme in the process of melanin formation and relates to the occurrence of freckles, brown spots, or excessive deposition of melanin in human body and other diseases. In this work, a turn-on fluorescence detection toward tyrosinase was developed. Manganese dioxide nanosheets were conveniently synthesized as an oxidizing agent. These nanosheets converted non-fluorescent o-phenylenediamine (OPD) into a fluorescent product. This reaction and the related fluorescence could be inhibited by reductive dopamine. When tyrosinase was introduced, it catalyzed the oxidation of dopamine and thus led to a recovery of the fluorescence. This signaling provided enhanced fluorescence responses toward tyrosinase in the range 0.006–0.08 U/mL, with a detection limit at 0.003 U/mL. The scheme was successfully applied onto practical samples. [ABSTRACT FROM AUTHOR]

The low temperature atmospheric plasma are kinds of advanced oxidation processes (AOPs) reactors and have potential applications on gas cleaning and water treatment; however, the underlying reaction mechanisms of organic compounds degradation are not well understood. In this study, the gas phase multistep OH‐initiated dehydrogenations of p‐, m‐, and o‐phenylenediamine with C2h, C2, and C2 point groups were investigated using density functional theory. Intrinsic reaction calculations were performed for transition states at the M062X/Def2TZVPP level of theory. The distinct directed graphs of the predominant pathways are presented to elucidate the dehydrogenation processes of three isomers of phenylenediamines. The information reported in this paper reveals the AOPs of phenylenediamines. [ABSTRACT FROM AUTHOR]

1H-indol-2,3-dione (isatin) class of biologically active compounds have analgesic, anti-microbial, anti-inflammatory, anti-tubercular, anti-proliferative properties, and is also useful for the treatment of SARS-CoV. Schiff bases containing isatin moiety are known to have broad spectrum of biological activities like anti-viral, anti-tubercular, anti-fungal, and anti-bacterial. In this work, several Schiff base derivatives have been synthesized using two methods (synthetic and microwave) by reacting isatin with o-phenylenediamine. The synthesized compounds were structurally characterized and their in-vivo antimicrobial activity was tested against Gram-negative and Gram-positive bacteria using the inhibition zone method. Several newly synthesized isatin derivatives were found effective as antimicrobial agents and showed good potency (compounds 3c, 3d, 6a, 6b, 6d). Compound 3c displayed higher antimicrobial activity than standard drug (Amoxicillin) against Staphylococcus aureus at higher concentration (16 μg/mL) and against Escherichia coli at lower concentration (1 μg/mL). [ABSTRACT FROM AUTHOR]

Copyright of Istanbul Gelisim University Journal of Health Sciences / İstanbul Gelişim Üniversitesi Sağlık Bilimleri Dergisi is the property of Istanbul Gelisim Universitesi Saglik Bilimleri Yuksekokulu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fluorescent nitrogen and sulfur co-doped carbon dots (NSCDs) were synthesized using a simple one-step hydrothermal method starting from o-phenylenediamine (OPD) and ammonium sulfide. The prepared NSCDs presented a selective dual optical response to Cu(II) in water through the arising of an absorption band at 660 nm and simultaneous fluorescence enhancement at 564 nm. The first effect was attributed to formation of cuprammonium complexes through coordination with amino functional groups of NSCDs. Alternatively, fluorescence enhancement can be explained by the oxidation of residual OPD bound to NSCDs. Both absorbance and fluorescence showed a linear increase with an increase of Cu(II) concentration in the range 1–100 µM, with the lowest detection limit of 100 nM and 1 µM, respectively. NSCDs were successfully incorporated in a hydrogel agarose matrix for easier handling and application to sensing. The formation of cuprammonium complexes was strongly hampered in an agarose matrix while oxidation of OPD was still effective. As a result, color variations could be perceived both under white light and UV light for concentrations as low as 10 µM. Since these color changes were similarly perceived in tap and lake water samples, the present method could be a promising candidate for simple, cost-effective visual monitoring of copper onsite. [ABSTRACT FROM AUTHOR]

The benzene ring is fused to the 4 and 5 positions of the imidazole ring in the bicyclic heterocyclic aromatic compound known as benzimidazole. Benzimidazole is an important heterocyclic scaffold exhibiting a wide range of biological and pharmacological properties and plays a crucial role in drug design. It is synthesized by a straightforward nucleophilic substitution reaction and condensation method between o‐phenylenediamine and a carbonyl compound under various conditions. In recent years benzimidazole have gained more attention in chemistry due to their biomedical importance. This study focuses on synthesis of benzimidazole derivatives by numerous homogeneous catalysts related from s‐ block, p‐ block, transition metal, inner transition metal and environmentally benign synthetic approaches, via heterogeneous catalyst in metal‐free conditions. Benzimidazole has several applications in pharmaceuticals, agrochemicals and fine chemicals. Its scaffolds are omnipresent in several bioactive natural products and pharmaceutically important compounds. This review highlights synthetic approaches and studies of benzimidazole reported from the year 2020 onwards. [ABSTRACT FROM AUTHOR]

This review article discusses the recent progress in synthesizing seven-membered ring 1,3,5-triazepine and benzo[f][1,3,5]triazepine derivatives. These derivatives can be either unsaturated, saturated, fused, or separated. This review covers strategies and procedures developed over the past two decades, including cyclo-condensation, cyclization, methylation, chlorination, alkylation, addition, cross-coupling, ring expansions, and ring-closing metathesis. This review discusses the synthesis of 1,3,5-triazepine derivatives using nucleophilic or electrophilic substitution reactions with various reagents such as o-phenylenediamine, 2-aminobenzamide, isothiocyanates, pyrazoles, thiazoles, oxadiazoles, oxadiazepines, and hydrazonoyl chloride. This article systematically presents new approaches and techniques for preparing these compounds. It also highlights the biological importance of benzo[f][1,3,5]triazepine derivatives, which have been used as drugs for treating nervous system diseases. This review aims to provide researchers with the necessary information to create and develop new derivatives of these compounds as quickly as possible.

Zirconium phosphate (α‐ZrP) was modified by o‐phenylenediamine (OPD) grafting to its surface, named ZPD, and used to improve thermal‐oxidative stability of nitrile butadiene rubber (NBR) by direct blending method. The results of Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), X‐ray diffraction, and contact angle test, demonstrated that OPD was grafted to the surface of α‐ZrP successfully. Scanning electron microscopy results showed that OPD could effectively improve the interaction between α‐ZrP and NBR and a better the dispersion of α‐ZrP in the rubber matrix. The fracture strength of the NBR composites was increased by 3.3 Mpa with the addition of 3 phr ZPD fillers, respectively, compared with unmodified NBR/α‐ZrP composites. In addition, TGA, DMA, and FWO analysis showed ZPD fillers, combined lamellar barrier of α‐ZrP with radical trapping ability of OPD, could retard oxidative cross‐linking and fracture reaction of rubber chains, and improve the thermal‐oxidative aging resistance of the NBR composites. This work provides a practical and effective methodology for surface modification of α‐ZrP and preparation of high‐performance NBR composites. [ABSTRACT FROM AUTHOR]

A new fluorescence strategy was described for ratiometric sensing of formaldehyde (FA) with bifunctional MOF, which acted as a fluorescence reporter as well as biomimetic peroxidase. With the assistance of H2O2, NH2-MIL-101 (Fe) catalyzes the oxidation of non-luminescent substrate o-phenylenediamine (OPD) to produce fluorescent product (oxOPD) with the maximum emission at 570 nm. Besides, intrinsic fluorescence of MOF (λem = 445 nm) was quenched by oxOPD through inner filter effect (IFE). However, FA and OPD reacted to generate Schiff bases, which competitively consumed OPD inhibiting the generation of oxOPD. Under the excitation wavelength of 375 nm, a ratiometric strategy was designed to detect FA with the fluorescence intensity ratio at 445 nm and 570 nm (F445/F570) as readout signal. This strategy exhibited a wide linear range (0.1–50 μM) and low detection limit of 0.03 μM. This method was confirmed for FA detection in food samples. In addition to establishing a new method to detect FA, this work will open new applications of MOF in food safety. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A photo-induced metal–organic framework-enzyme hybrid nanosystem was developed via a controllable physical embedding method that displays dual enzymatic and photo-non-enzymatic strategy which cause high stability and cascade catalytic performance to oxidation of o-phenylenediamine and generate a UV–Vis signal at 450 nm for the tracing and sensitive detection of putrescine (Put). Under optimal conditions, the present bioassay provides a wide detection range from 0.02 to 10 µM and 20–80 µM with a detection limit of 5.5 nM, which is more desirable than numerous previous reports. In addition, the established colorimetric photo-bioassay can selectively and accurately identify Put in the presence of other distributing species. The present work provides an elegant strategy to merged photo-nanozymes' and enzyme capabilities and also broadened the sensing strategies of photo-nanozymes with promising potential in the realm of cancer diagnosis and food quality monitoring as well as its potential in various bioassays and heterogeneous catalysis fields. [ABSTRACT FROM AUTHOR]

• A novel method for synthesis of benzimidazolone using ionic liquid as a catalyst without solvent. • Employed carbon dioxide as an environmentally friendly carbonyl source, reducing reliance on hazardous chemicals. • Identified an ionic liquid that significantly enhances reaction yield and selectivity. • Provided detailed mechanistic studies elucidating the role of the ionic liquid in the reaction. • Demonstrated a sustainable and reusable catalytic system up to six run that aligns with green chemistry principles. In this study, we report synthesis of benzimidazolones from o-phenylene diamine by utilizing carbon dioxide as a carbonyl source under mild reaction conditions in the presence of ionic liquid as a catalyst. Six bifunctional protonic ionic liquids (PILs) were synthesised by reacting superbases 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) and 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU) with proton donors such as Trifluoroethanol (TFE), Cyclopropane carboxylic acid (CPCA) and 2,2,2-Trifluoroacetic acid (TFA). Among them, [TBDH+][TFE−] was the most effective, achieving high conversion rates of o-phenylene diamine to 2-benzimidazolone at 1 bar CO 2 pressure and 60° C. This PIL could be reused for up to six cycles. Our method offers a green and efficient approach for producing 2-benzimidazolone derivatives, with potential applications in pharmaceuticals and materials science. [ABSTRACT FROM AUTHOR]

[Display omitted] • A plasmonic ELISA for NGAL was fabricated by Ag+-catalyzed OPD oxidation. • The plasmonic ELISA integrated cascade amplification and dual-readout. • The plasmonic ELISA rapidly and specifically senses NGAL with the LOD of 0.5 ng/mL. • AA inhibited AgNPs' autocatalytic activity by aggregating AgNPs. The conventional ELISA lacked sufficient sensitivity and accuracy for analyzing neutrophil gelatinase associated lipocalin (NGAL), a potential biomarker of ulcerative colitis. Here, we developed a dual-readout plasmonic ELISA with cascade amplification of alkaline phosphatase hydrolysis and O-phenylenediamine oxidation. In this novel plasmonic ELISA, alkaline phosphatase-conjugated antibodies capture NGAL from samples, alkaline phosphatase hydrolyzes 2-phospho-L-ascorbic acid into ascorbic acid, and then ascorbic acid blocks silver-catalyzed O-phenylenediamine oxidation by turning silver ions into silver microwires. Therefore, NGAL concentration is proportional to the decrease in chromogenic and fluorescent response. This novel plasmonic ELISA exhibited a linear range of 0.5–80 ng/mL, and the LOD was as low as 0.5 ng/mL. The sensitivity was superior to that of conventional ELISA and previous studies. The plasmonic ELISA exhibited favorable selectivity because of the specific antibody-antigen interaction and the robust cascade amplification. Besides, the dual-readout feature endowed the plasmonic ELISA with advantages in terms of convenience and compatibility. In summary, our study provided a novel and sensitive plasmonic ELISA for the diagnosis of ulcerative colitis. [ABSTRACT FROM AUTHOR]

In this work, iron nanoparticles (FeNPs) were synthesized by a green method using Eucalyptus grandis leaf extract as a reducing and stabilizing agent. The FeNPs were employed as nanoenzymes for oxidizing o -phenylenediamine, enabling the development of a spectrophotometric method to detect and quantify hydrogen peroxide in milk. The method was validated according to the validation protocols. The analytical curve (8.97–112.16 µmol L−1) for UHT (Ultra High Temperature) whole milk showed a good linear fit. The limits of detection and quantification were 2.96 µmol L−1 and 9.89 µmol L−1, respectively. The method demonstrated an accuracy ranging from 85.1 % to 102.8 %, with a repeatability of ≤ 3.9 % and an intermediate precision of ≤ 7.5 %. The method proved its effectiveness on various types of milk and was compared with other conventional methods traditionally applied to milk analysis. The novelty of the method lies in the use of FeNPs synthesized through a bioinspired process using plant extract, employed for the first time in the detection of H 2 O 2 in milk, a highly complex matrix. The advantages of the analytical method include the use of a small sample and reagent volumes. The ecological aspects of the developed procedure were evaluated using the Analytical Eco-scale protocols, resulting in a score of 77, classified as an excellent green analysis, confirming it as an environmentally friendly method. [Display omitted] • Iron nanoparticles (FeNPs) synthesized by green method exhibited excellent stability. • For the first time, FeNPs were used as catalase mimetics for detecting H 2 O 2 in milk. • Simple sample preparation involves the addition of HNO 3 followed by centrifugation. • The method showed sensitive LoD and LoQ, with a small sample volume needed. • The method was effective in detecting peroxide in various types of milk. [ABSTRACT FROM AUTHOR]

In this study, a nanozyme (ZIF-Co-Cys) with high oxidase-like catalytic activity was prepared, and a ratiometric fluorescent/photothermal dual-mode probe was constructed for organophosphorus pesticides (OPs) detection based on the competitive effect of ZIF-Co-Cys and the enzymatic reaction product of acid phosphatase (ACP) on o -phenylenediamine and the inhibition effect of OPs on ACP activity. Using dimethyl dichloroviny phosphate (DDVP) as the model, both the fluorescence intensity ratio and the temperature change of the probe solution exhibited an excellent correlation with OPs concentration. The detection limits were 1.64 ng/mL and 0.084 ng/mL, respectively. Additionally, the detection of DDVP residues in real samples verified the outstanding anti-interference and accuracy of the probe. This work not only provided a complementary dual-mode method for the accurate and rapid detection of OPs residues in complex samples, but also supplied a new insight into the design of a multi-mode sensing platform based on the cascade reaction of nanozyme. [Display omitted] • A dual-mode probe was constructed based on cascade reactions regulated by nanozyme. • It realized ratiometric fluorescent and photothermal detection for OPs. • It exhibited high sensitivity, low detection limit, and excellent selectivity. • The reliability was improved by mutual verification of the results of two modes. [ABSTRACT FROM AUTHOR]