A novel impedance immunosensor based on O-phenylenediamine modified gold electrode to analyze abscisic acid

An impedance immunosensor based on O-phenylenediamine modified gold electrode for the determination of phytohormone abscisic acid(ABA) was proposed.The operating pH,absorption time,absorption temperature and concentration of anti-ABA antibody were investigated to optimize the analytical performance.The calibration curve for the determination of ABA was obtained from this impedance immunosensor under optimal conditions.The results showed that the detection limit at about 1 ng/mL in the range of 10-5000 ng/mL...

Polymerization of o-Phenylenediamine Catalyzed byHemeproteins Encapsulated in Reversed Micelle

Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate(AOT) was found to catalyze the polymerization of o-phenylenediamine(o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed by hemeproteins dissolved in water could only form its trimers. As the nanostructural environment in reversed micelle acts as a certain orientation surrounding medium, it offers a strong electrostatic field that alters the reductive potential of Fe 3+/Fe 2+(E m7) in the heme of hemeproteins and thus increases the catalytic activity of peroxidase accordingly. According to the results of UV-Vis, 1H NMR and FTIR, the polymer catalyzed by hemoglobin(Hb) in reversed micelle was presumed to be constructed of lines and trapeziforms alternatively.

Studies on the Reaction Between α－Acetylthioformanilide and o-Phenylenediamine

,3-Disubstituted quinoxalines were synthesized from α-acetylthioformanilide and ophenylenediamine. Further studies sliowed that there existed competitive re- actions. One was a condensation reaction which produced substituted quinoxaline and the other was a substitution reaction which produced substituted quinoxaline-2- thione.

THE REACTION OF ETHYL AROYLACETATES AND o-PHENYLENEDIAMINE

Instead of 2-(aroylmethylene)benzimidazolines 3 or 2-(aroyl-methyl)benzimidazoles 4, 4-aryl-2, 3-dihydro-1H-1, 5-benzodiazepin-2-ones 5 were obtained exclusively from the reaction of o-phenylenediamine (1) and ethyl aroylacetates 2 in the presence of a catalytic amount of potassium hydroxide.

Robust magnetic laccase-mimicking nanozyme for oxidizing o-phenylenediamine and removing phenolic pollutants

In this study, we report a novel magnetic biomimetic nanozyme(Fe3O4@Cu/GMP(guanosine5′-monophosphate)) with high laccase-like activity, which could oxidize toxic ophenylenediamine(OPD) and remove phenolic compounds.The magnetic laccase-like nanozyme was readily obtained via complexed Cu2+and GMP that grew on the surface of magnetic Fe3O4 nanoparticles.The prepared Fe3O4@Cu/GMP catalyst could be magnetically recycled for at least five cycles while still retaining above 70% activity.As a laccase mimic,Fe3O4@Cu/GMP had more activity and robust stability than natural laccase for the oxidization of OPD.Fe3O4@Cu/GMP retained about 90% residual activity at 90℃ and showed little change at pH 3–9, and the nanozyme kept its excellent activity after long-term storage.Meanwhile, Fe3O4@Cu/GMP had better activity for removing phenolic compounds, and the removal of naphthol was more than 95%.Consequently, the proposed Fe3O4@Cu/GMP nanozyme shows potential for use as a robust catalyst for applications in environmental remediation.

VO(acac)_2 catalyzed condensation of o-phenylenediamine with aromatic carboxylic acids/aldehydes under microwave radiation affording benzimidazoles

Vanadyl acetylacetonate,VO（acac）_2,has been found to be very effective catalyst for synthesis of a variety of benzimidazoles under solvent-free condition.The methodology involves the exposure of a mixture of o-phenylenediamine and a selected aromatic carboxylic acid/aldehyde to microwave radiation without the use of any solvent or supporting agents.The benzimidazoles were obtained in quick time with high yields.

Imine-Rich Poly(o-phenylenediamine) as High-Capacity Trifunctional Organic Electrode for Alkali-Ion Batteries

Alkali-ion batteries,including potassium-ion batter-ies,lithium-ion batteries,and sodium-ion batteries are important energy storage devices;however,with the cation size increased,there exists a great challenge for an inorganic electrode material to accommodate the different properties of the alkali-ion.Herein,as a proof-of-concept experiment,an imine-rich poly(o-phenylenediamine)(PoPD)is syn-thesized through a rational controllable oxidization.Due to the abundance of active sites and ladder-conjugated structure,PoPD in the optimized oxida-tion state endows alkali-ion batteries with a stable cyclability at high capacity.The highly reversible redox performance of PoPD with alkali-ions is verified by theoretical calculations and demonstrat-ed as a trifunctional electrode material(537 and 307 mAh·g^(−1) for Li and Na storage capacity after 300 cycles,respectively),especially for successful application in potassium storage(450 mAh·g^(−1) after 205 cycles),and provides compelling evidence for the wide application of organic electrode materials.

In（OTf）3-Catalyzed Synthesis of Functionalized 1,5-Benzodiazepines from o-Phenylenediamine and Alkyl Propiolates under Solvent-Free Reaction Conditions

A simple, environmental-friendly, and practical method for the synthesis of benzodiazepine derivatives through a reaction of substituted o-phenylenediamines with alkyl propiolates has been developed. The reactions generated the 1,5-benzodiazepines in good to excellent yields in the presence of catalytic amount of In（OTf）3 under sol- vent-free reaction conditions.

A Theoretical Study of Tris-(o-benzoquinonediimine)-First-Row Divalent Transition Metal Complexes

The ligand o-phenylenediamine (opda) and its oxidized form, o-benzoquinonediimine (bqdi), act as a fascinating candidate coordinating toward transition metal ions leading to the photochemical hydrogen production in absence of photosensitizers. Herein, we report the systematic study of the interaction between the oxidized form bqdi ligand, tris-(o-benzoquinonediimine) with divalent first-row transition metal series using DFT calculations. The lowest energy structures, bond length, binding energies, frontier molecular orbital analysis, natural bond orbitals, and global reactivity descriptor were calculated using B3LYP/6-311G(d,P) level of theory. The time dependent-DFT at the CAM-B3LYP/6-311+G(d,p) level of theory was applied to determine the electronic structures and the optical spectra. The theoretical binding trend of the divalent first-row transition metal series is decreasing as follows: Cu >Ti > V > Co > Ni > Fe > Cr > Zn >Mn. Among them, the binding potency of iron (II) by the bqdi ligand was not predominantly sturdy as compared to other first-row divalent transition metal ions. The origin of strong coordination with Fe(II) is attributed to its extra capability to induce covalent coordination of bqdi ligands. The complex exhibited two strong peaks at 370 nm and 452 nm, due to the HOMO-3 to LUMO+1 and HOMO-1 to LUMO transitions, respectively. Natural bond orbital analysis showed that the major interaction happens between the N lone pair electrons of the ligand with an anti-bonding orbital of metal ions, in which Ti showed the highest interaction energy than other metal ions. The present systemic DFT study of bqdi ligands with the first-row transition metals strongly encourages the future establishment of photochemical hydrogen production in absence of photosensitizers.

Determination of hydroxyl radical in Fenton system

Under visible light illumination, 2,3-diaminophenazine （DAPN） was generated from the oxidation of o-phenylenediamine （OPDA） in Fe^3＋/H2O2 solution. Hydroxyl radical （＊OH） produced in this system was determined by directly measuring the concentration of DAPN. In comparison with the traditional methods, the determination is more accurate and simple.

An efficient synthesis of 1,5-benzodiazepine derivatives catalyzed by boric acid

1,5-Benzodiazepine derivatives have been synthesized by the condensation of o-phenylenediamines and ketones in the presence of boric acid as catalyst under mild conditions. This method is simple, environmentally benign and high yielding. ？2009 Chun Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Glyoxylic acid as catalyst:A simple selective synthesis of 1,2-disubstituted benzimidazoles in aqueous media

Glyoxylic acid （5 mol%） performs as a novel highly water-soluble catalyst for the synthesis of 2-aryl-l-arylmethyl-lH- benzimidazoles from a wide range of substituted o-phenylenediamines and various substituted aldehydes in good to excellent isolated yields （85-95%） using water as solvent at ambient temperature. The remarkable advantages offered by this method are easily and inexpensive available catalyst, simple procedure, mild conditions, much faster （20--40 rain） reactions and excellent yields of products.

非晶态介孔FeAlP催化剂用于合成1,5-苯二氮类化合物(英文)

A simple and versatile method for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones in the presence of solvents and under solvent-free conditions that used an amorphous mesoporous iron aluminophosphate as catalyst was developed.High yields with excellent selectivity were obtained with a wide variety of ketones under mild reaction conditions.The catalyst had the advantages of ease of preparation,ease of handling,simple recovery,reusability,non toxicity,and being inexpensive.

Novel,efficient,and green procedure for the synthesis of 1,5-benzodiazepines catalyzed by MgBr_2 in aqueous media

MgBr2 performs as a novel catalyst for the synthesis of various 1,5-benzodiazepine derivatives from wide range of substituted o- phenylenediamines and various ketones in good to excellent isolated yields （93-98%） using water as solvent at ambient temperature. Several solvents were examined for this reaction; however, in terms of reaction yield and time, water was found to be the optimum solvent. The remarkable advantages offered by this method are easily and inexpensive available catalyst, simple procedure, mild conditions, much faster （40-60 man） reactions and good to excellent yields of products.

CONDENSATION OF 1,2-DIAMINES AND CARBOXYLICACIDS UNDER MICROWAVE IRRADIATION

A facile method of preparation of benzimidazoles by microwave irradiation was described. The mixtures of o-phenylenediamine and carboxylic acids were heated by microwave irradiation, to give 2-substituted benzimidazoles with yields of 49%～93%. The reaction time was shortened to 3～6 min. However, the reaction of ethylenediamine with carboxylic acids did not give imidazoles but the N,N-diacyl ethylenediamines. The alphatic diamines lacked the activity to form imidazole ring. With adipic acid, intermolecular acylation took place to afford poly(ethylene adipamide).

Synthesis and Crystal Structure of a New 3-Amino-3-deoxy Derivative from 3-Keto-D-xylose

The title compound 2 was synthesized by the reaction of 3-keto-D-xylose with O-C6H4NH2NH2 and characterized by IR, NMR and HRMS, and its crystal structure was determined by X-ray diffraction analysis. The crystal is of orthorhombic system （C21H22N2O5, Mr = 382.41）, space group P2 1 2 1 2 1 with α = 10.140（2）, b = 10.802（2）, c = 17.840（4） A, β = 90°, V = 1954.1（7）A^3, Z = 4, Dc = 1.300 g/cm^3, F（000） = 808, μ = 0.094 mm^-1, the final R = 0.0354 and wR = 0.0514 for 1924 observed reflections （I 〉 2σ（I））. One intermolecular and one intramolecular hydrogen bonds were found. The absolute configuration of this molecule was confirmed by comparison with that of the original material.

Synthesis of Multifunctionalised 2-Substituted Benzimidazoles Using Copper (II) Hydroxide as Efficient Solid Catalyst

Here we demonstrate the synthesis of multifunctionalised benzimidazoles through the coupling of o-phenylenediamine with aldehydes by using Copper (II) hydroxide as an efficient solid catalyst in methanol at room temperature. The Copper (II) hydroxide solid catalyst gave better yields (80%-99%) in short reaction time (4-8 h). These commercially available cheap catalysts are more active than many reported expensive heterogeneous catalysts. Using the Copper hydroxide fresh catalyst, the yield of product 3a was 98%, while the recovered catalyst in the three subsequent cycles gave the yield of 94%, 90% and 88% respectively.

<i>In Situ</i>UV–Vis Spectroelectrochemical Studies on the Copolymerization of Diphenylamine and <i>o</i>-Phenylenediamine

The in situ ultraviolet-visible (UV-Vis) spectroelectrochemical study on the copolymerization of diphenylamine (DPA) and o-phenylenediamine (OPD) has been performed at a constant potential of 0.8 V using indium tin oxide (ITO)-coated glass electrodes as working electrode. And also, as a comparison, the electrochemical homopolymerizations of DPA and OPD have been investigated by using the in situ spectroelectrochemical technique. The intermediate species generated during the electrochemical homopoly-merization of DPA and OPD, and the copolymerization of DPA with OPD have been identified by using the in situ spectroelectrochemical procedure. The results reveal the formation of an intermediate in the initial stage of copolymerization through the cross-reaction of the cation radicals of DPA and OPD, and the absorption peak located at 538 nm in the UV–Vis spectra is assigned to this intermediate. To further investigate the copolymerization of DPA with OPD, cyclic voltammetry (CV) has been used to study the electrochemical homopolymerization of DPA and OPD and also the copolymerization of DPA and OPD with different concentration ratios in solution. The different voltammetric characteristics between the homopolymerization and copolymerization processes exhibit the occurrence of the copolymerization, and the difference between the copolymerization of DPA and OPD with different concentration ratios shows the dependence of the copoly-merization on the concentrations of DPA and OPD. The copolymer has also been characterized by Fourier transform infrared spectroscopy (FT-IR).

Reactive oxygen species and nitric oxide scavenging nanoparticles alleviating rheumatoid arthritis through adjusting the seeds and growing soils

Normalizing inflamed soils including reactive oxygen species(ROS),nitric oxide(NO),cellfree DNA,and regulating infammation-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 infammatory 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.

Polyethylene glycol(PEG-400):An efficient and recyclable reaction medium for the synthesis of novel 1,5-benzodiazepines and their antimicrobial activity

A new series of imidazole-containing 1, 5-benzodiazepines have been synthesized by the condensation of chalcones with o- phenylenediamine using piperidine in polyethylene glycol （PEG-400） as an efficient and green reaction solvent. The advantages of this protocol are environmental friendliness, easy work-up, high yields, mild reaction condition and avoidance of expensive catalyst. Furthermore, newly synthesized compounds were evaluated for their antimicrobial activity.