Reaction Of Hydrazine Research Articles

Redox Reaction Triggered Nanomotors Based on Soft-Oxometalates With High and Sustained Motility.

The recent interest in self-propulsion raises an immediate challenge in facile and single-step synthesis of active particles. Here, we address this challenge and synthesize soft oxometalate nanomotors that translate ballistically in water using the energy released in a redox reaction of hydrazine fuel with the soft-oxometalates. Our motors reach a maximum speed of 370 body lengths per second and remain motile over a period of approximately 3 days. We report measurements of the speed of a single motor as a function of the concentration of hydrazine. It is also possible to induce a transition from single-particle translation to collective motility with biomimetic bands simply by tuning the loading of the fuel. We rationalize the results from a physicochemical hydrodynamic theory. Our nanomotors may also be used for transport of catalytic materials in harsh chemical environments that would otherwise passivate the active catalyst.

Lewis Acid Catalyzed Annulation of Cyclopropane Carbaldehydes and Aryl Hydrazines: Construction of Tetrahydropyridazines and Application Toward a One-Pot Synthesis of Hexahydropyrrolo[1,2- b]pyridazines.

In this report, a facile synthesis of tetrahydropyridazines via a Lewis acid catalyzed annulation reaction of cyclopropane carbaldehydes and aryl hydrazines has been demonstrated. Moreover, the generated tetrahydropyridazine further participated in a cycloaddition reaction with donor-acceptor cyclopropanes to furnish hexahydropyrrolo[1,2- b]pyridazines. We also performed these two steps in one pot in a consecutive manner. In addition, a monodecarboxylation reaction of hexahydropyrrolo[1,2- b]pyridazine was achieved with a good yield.

Dye-sensitized hematite compososite photocatalyst and its photocatalytic performance of aerobic annulation

A visible light initiated catalyst (DP-pfa@Fe2O3) is synthesized and used as a photocatalyst for the synthesis of pyrazoles under mild reaction conditions. Holes (h+) and OH are the essential for the light-induced the pyrazole annulation reaction using water as oxygen source. Results demonstrate that photocatalyzed reaction of methyl hydrazine and 2-benzylidenemalononitrile produced 2-((2-methylhydrazinyl)(phenyl)methylene)malononitile, which can transfer into pyrazoles in the presence of ∙ OH. Our results provide a new catalyst and an economic synthetic method for the synthesis of pyrazoles through aerobic annulation.

Ce(III) immobilized on aminated poly(vinyl chloride): high-performance synergistic bifunctional acid–base catalyst for one-pot synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles

A bifunctional acid–base catalyst of CeIII immobilized on ethylenediamine (EDA)-grafted poly(vinyl chloride) (PVC) has been prepared by a simple approach. First, PVC was treated with EDA to afford aminated poly(vinyl chloride) (PVC–EDA). Thereafter, the PVC–EDA were used in the mobilization of CeCl3 to obtain a bifunctional catalyst (PVC–EDA–CeIII) in which a harmonious coexistence of Lewis acid (Ce3+) sites and Lewis base (amine) moieties on PVC was achieved. The obtained PVC–EDA–CeIII complex was characterized by EA, ICP–AES, FT-IR, SEM, EDS, TGA, and DTG techniques. The as-prepared catalyst can efficiently catalyze the one-pot four-component reactions of aromatic aldehydes, malononitrile, ethyl acetoacetate, and hydrazine in ethanol under mild conditions to afford polyfunctionalized 1,4-dihydropyrano[2,3-c]pyrazoles with excellent yields. The high catalytic performance of the PVC–EDA–CeIII bifunctional catalyst is attributed to a synergistic effect of Lewis acid sites (CeIII) and Lewis base sites (amino moieties). The significant features of the present protocol are environmentally benign, simple operation, short reaction time, high yields, and without chromatographic separation. Moreover, the catalyst can easily be separated by simple filtration and reused for five runs without obvious decline or losing its catalytic activity.

Synthesis of Polyaryl-Substituted Olefins via a Rh(III)-Catalyzed One-Pot Reaction Using N-Phenoxyacetamides, Ketones, and Hydrazines.

A Rh(III)-catalyzed one-pot reaction of N-phenoxyacetamides, ketones, and hydrazines for a facile access to disubstituted and trisubstituted ethylenes is reported. In this method, various ketones are transformed into donor-donor diazo compounds, which engage in insertion with N-phenoxyacetamides, following β-H elimination under Rh(III) catalysis to generate (E)-polyaryl-substituted olefins. This chemistry features simple starting materials, mild reaction conditions, and good functional group tolerance.

Use of Hydrazine for Pitting Corrosion Inhibition of Copper Sprinkler Tubes: Reaction of Hydrazine with Corrosion By-Products

Use of Hydrazine for Pitting Corrosion Inhibition of Copper Sprinkler Tubes: Reaction of Hydrazine with Corrosion By-Products

Magnetic Co-Doped MoS2 Nanosheets for Efficient Catalysis of Nitroarene Reduction.

Co-doped MoS2 nanosheets have been synthesized through the hydrothermal reaction of ammonium tetrathiomolybdate and hydrazine in the presence of cobalt acetate. These nanosheets exhibit a dominant metallic 1T phase with cobalt ion-activated defective basal planes and S-edges. In addition, the nanosheets are dispersible in polar solvents like water and methanol. With increased active sites, Co-doped MoS2 nanosheets exhibit exceptional catalytic activity in the reduction of nitroarenes by NaBH4 with impressive turnover frequencies of 8.4, 3.2, and 20.2 min–1 for 4-nitrophenol, 4-nitroaniline, and nitrobenzene, respectively. The catalyst is magnetic, enabling its easy separation from the reaction mixture, thus making its recycling and reusability simple and efficient. The enhanced catalytic activity of the Co-doped 1T MoS2 nanosheets in comparison to that of undoped 1T MoS2 nanosheets suggests that incorporation of cobalt ions in the MoS2 lattice is the major reason for the efficiency of the catalyst. The dopant, Co, plays a dual role. In addition to providing active sites where electron transfer is assisted through redox cycling, it renders the nanosheets magnetic, enabling their easy removal from the reaction mixture.

Gold Nanoparticle-Catalyzed Clock Reaction of Methylene Blue and Hydrazine for Visual Chronometric Detection of Glutathione and Cysteine

A visual chronometric assay for glutathione (GSH) and cysteine (Cy) is reported based on a gold nanoparticle (AuNP)-catalyzed clock reaction of methylene blue and hydrazine. The blue MB is reduced ...

Biosynthesis of Ag nanoparticles using isolated bacteria from contaminated sites and its application as an efficient catalyst for hydrazine electrooxidation

In the present study, a bacterium resistance to heavy metals was isolated from contaminated areas. An eco-friendly and simple method was found to biosynthesis of silver nanoparticles (AgNPs) by reducing of aqueous Ag+ using the heavy metals resistance MKH1 bacterium. The biosynthesized AgNPs were characterized by UV–vis spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. A peak at about 420nm is related to absorption band of AgNPs which confirms by UV-vis spectroscopy. The SEM images showed that the biosynthesized AgNPs have mainly spherical shape with average diameters of 30–60nm. The electro-catalytic properties of AgNPs with different Ag content were investigated by different electrochemical tests. Biosynthesized AgNPs using isolated MKH1 show high catalytic activity and stability towards the oxidation reaction of hydrazine.

A sensitive and selective amperometric hydrazine sensor based on palladium nanoparticles loaded on cobalt-wrapped nitrogen-doped carbon nanotubes

In this work, a sensitive and selective hydrazine amperometric sensor was developed for the first time using palladium nanoparticles (Pd NPs) loaded on cobalt nanoparticles (Co NPs) wrapped in nitrogen-doped carbon nanotubes (Pd/Co-NCNTs). The Co-NCNTs synthesized by facile one-step pyrolysis combine with Pd NPs to exhibit high catalytic response and low overpotential for hydrazine oxidation. The morphology and composition of prepared nanomaterial were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Raman spectroscopy. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize Pd/Co-NCNTs for electrochemical oxidation performance of hydrazine and define the mechanism of hydrazine reaction at the electrode. Under the optimized conditions, an amperometric sensor for hydrazine detection was established, and exhibited a wide linear range of 0.05–406.45μM with low detection limit (S/N=3) of 0.007μM and the response of the sensor for hydrazine detection lies within 2s. The prepared sensor demonstrates a long-term stability along with a very good sensitivity.

Determination of Trace Hydrazine in Environmental Water Samples by in situ Solid Phase Extraction.

A simple and rapid in situ method for the determination of hydrazine based on the concentration of aldazine compound formed by the reaction of hydrazine with p-dimethylaminobenzaldehyde was developed. This method was based on solid-phase extraction using a Sep-Pak C18 cartridge, followed by the quantification of hydrazine using a spectrophotometric method. To a sample solution of environmental water, p-dimethylaminobenzaldehyde solution was added to form aldazine by the reaction with hydrazine. The solution was passed through a Sep-Pak C18 cartridge for the adsorption of aldazine. In the laboratory, the aldazine adsorbed on the Sep-Pak C18 cartridge was eluted by passing a hydrochloric acid-ethanol (1:10) solution through the cartridge, and the color intensity of the solution was measured at 457 nm. The limit of detection for the new method was 0.2 mgN L-1 of hydrazine. The determination of hydrazine in solution was not influenced even by hydrogen sulfide and organic matter. This method was then applied to the brackish water of Lake Nakaumi in the eastern area of Shimane Prefecture, Japan. This method was used to determine hydrazine in freshwater, seawater and wastwater.

A Continuous-Flow Fischer Indole Synthesis of 3-Methylindole in an Ionic Liquid

A continuous-flow reactor (Corning G1 reactor) was hereby introduced for Fischer indole synthesis of 3-methylindole by reaction of phenyl hydrazines and propylaldehyde. Stoichiometric Lewis acid, ZnCl2, was supplied as catalyst as well as remover of NH3 which generated during the indole ring formation. Ionic liquid ([EMIM][BF4]) was employed as solvent according to its high-temperature tolerance and good product distribution. After a straightforward extraction process, 3-methylindole could be obtained in a 95.3% yield (96.0% purity) under optimized conditions. Ionic liquid (IL) was then recovered by another extraction process, and the recovered IL acted nearly as efficiently as new IL for this Fischer indole reaction.

Water-acetic acid mediated chemoselective synthesis of pyrazolines via multimolecular domino reactions of enaminones and sulfonyl hydrazines

The domino reactions between enaminones and sulfonyl hydrazines enabling novel synthesis of pyrazoline have been achieved by employing water as reaction medium and acetic acid as cheap and green additive are reported. Two new CN and one new CN bonds have been constructed during the formation of these pyrazoline scaffolds. Unlike the conventional formation of pyrazoles in the organic solvent mediated reactions of enaminones and hydrazines, the present reactions providing pyrazolines disclose new transformation pattern of enaminones by employing water as medium.

Theoretical study on the mechanism of the N2H4 plus O2 reaction on the singlet and triplet potential energy surfaces

Kinetic and mechanism of atmospheric reaction of hydrazine (N2H4) and molecular oxygen (O2) on the singlet and triplet potential energy surfaces have been investigated in details using ab initio and DFT methods. All stationary points involved in the title reaction were optimized at the B3LYP, MP2 and G3B3 methods of computation in connection with the 6-311++G (3df, 3pd) basis set. For calculation of accurate energies, the CCSD(T) method is applied. Also, thermodynamic parameters and rate constant are calculated at M06-2x method with the mentioned basis set. The results show that direct hydrogen abstraction mechanism is the most important pathways of reaction. Three pre-reactive complexes, 1C1, 1C2, 3C1, on the singlet and triplet potential energy surfaces were formed between hydrazine and molecular oxygen. Seven different products are suggested which all of them have enough thermodynamic stability. The production of HNNH+H2O2 and H2N2(OH)2 are the main reaction channels in thermodynamic viewpoint with standard Gibbs free energy of ∆G0=−41.9 and −54.1kcal/mol at M06-2x level, respectively. In kinetic point of view, H2NN+H2O2 adduct (on singlet state) and 2N2H3+2HO2 adducts (on singlet and triplet states) after passing one corresponding low level transition state are the most favor pathways of reaction. In this reaction, N2H3+HO2 adducts in singlet and triplet states are the main kinetically products. So, the rate constants are calculated at the 300–2500K temperature range for the reliable pathway of the mentioned adducts in both states at M06-2X/6-311++(3df, 3pd) method.

Two {Dy2} single-molecule magnets formed via an in situ reaction by capturing CO2 from atmosphere under ambient conditions.

Under ambient conditions, CO2 was captured from atmosphere and reduced for sequestering CO2 into two {Dy2} single-molecule magnets through an in situ organic ligand reaction of hydrazine. A reasonable reaction mechanism is proposed, which provides a promising route towards the capturing and transforming CO2 into single-molecule magnets.

Transition-metal-free oxidative reaction of hydrazines and potassium metabisulfite for preparation of sulfonohydrazides

A coupling reaction for the synthesis of sulfonohydrazides from two types of hydrazines and K2S2O5 under air was developed.

Half-sandwich ruthenium, rhodium and iridium complexes of triazolopyridine ligand: Synthesis and structural studies

Triazolopyridine ligand, {3-(2-pyridyl)-[1,2,3]triazolo[1,5-a]-pyridine}, L was synthesized by reaction of p-toulenesulphonyl hydrazine and dipyridyl ketone in the presence of acetic acid. Half-sandwich ruthenium, rhodium and iridium complexes [1–4] have been synthesized by reaction of [{(arene)MCl 2} 2] (arene = p-cymene/benzene/Cp* and M = Ru/Rh/Ir) with ligand L in methanol. The reaction in 1:2 (M:L) ratio has yielded all mononuclear cationic complexes such as [(arene)ML\(\kappa ^{2}_{\mathrm {N\cap N}}\)Cl]PF 6, where {(arene)M} = (p-cym)Ru (1), (benz)Ru (2), Cp*Rh (3) and Cp*Ir (4). All the complexes were characterized by spectral studies and the solid state structures of complexes, 1 and 3 were unambiguously determined by crystallographic studies. Triazolopyridine ligand, {3-(2-pyridyl)-[1,2,3]triazolo[1,5-a]-pyridine} L was synthesized by reaction of p-toulenesulphonyl hydrazine and dipyridyl ketone in the presence of acetic acid. Half-sandwich ruthenium, rhodium and iridium complexes [1-4] were synthesized by reaction of [{(arene)MCl2}2] (arene = p-cymene/benzene/Cp* and M = Ru/Rh/Ir) with ligand L in methanol. All the complexes were characterized by spectral studies and the solid state structures of two complexes were unambiguously determined by crystallographic studies.

Copper‐Catalyzed Selective Aerobic Oxidative Cascade Reaction of Hydrazines, DABSO, and Amines for the Direct Synthesis of Sulfonamides

AbstractA Cu‐catalyzed highly selective aerobic oxidative coupling reaction of hydrazines and amines has been achieved with the use of 1,4‐diazabicyclo[2.2.2]octane bis(sulfur dioxide) (DABSO) as a sulfonyl group source. The hydrazines were explored as aryl precursors for the coupling reaction with DABSO, which directly reacted with amines without use of any additional additives. The cascade reaction was performed under mild conditions and tolerated a wide range of substrates affording the corresponding sulfonamides with good chemical yields. This conceptually new method proceeds with the release of nitrogen, providing an easy and practical strategy for the preparation of sulfonamides.

Lewis acid-promoted direct synthesis of N-unsubstituted hydrazones via the reaction of hydrazine with acetophenone and isatin derivatives

Hydrazones 2–22 were synthesized via the reaction of acetophenone with isatin derivatives and anhydrous hydrazine promoted by BF3 as a Lewis acid at 0°C. Structures of the synthesized hydrazones were determined on the basis of NMR and X-ray crystallographic analyses.

A novel fluorescent probe for sensitive detection and imaging of hydrazine in living cells

A turn-on fluorescent probe (Naphsulf-O) for hydrazine was developed by protecting the hydroxy group of the fluorophore 6-acetyl-2-hydroxynaphthalene via O-4-nitrobenzenesulfonylation, where 4-nitrobenzene was used as a fluorescence quenching moiety as well as an electrophile. Upon nucleophilic aromatic substitution (NAS) reaction of hydrazine toward the probe, the protecting group was removed and fluorophore was released. The probe exhibits a large Stokes shift, excellent selectivity and high sensitivity for hydrazine detection in aqueous solution with a detection limit of 0.716 ppb (22nM), which is of great importance in both environmental and biological system. Furthermore, it was successfully applied to imaging of hydrazine in living cells.