Indirect simultaneous kinetic determination of semicarbazide and hydrazine in micellar media by H-point standard addition method

H-point standard addition method (HPSAM) is suggested as a simple and selective method for the determination of semicarbazide and hydrazine. The reduction of Cu²⁺ to Cu⁺ by semicarbazide and hydrazine in the presence of neocuproine (Nc) and the subsequent complex formation between Cu⁺ and Nc produced a sensitive spectrophotometric method for indirect determination of semicarbazide and hydrazine. The difference in the rate of reduction of Cu²⁺ with semicarbazide and hydrazine in cationic micellar media is the basis of this method. Semicarbazide can be determined in the range of 0.5-3.75 μg ml⁻¹ with satisfactory accuracy and precision in the presence of excess hydrazine. The proposed method was successfully applied to the simultaneous determination of semicarbazide (0.5-3.75 μg ml⁻¹) and hydrazine (0.5-5 μg ml⁻¹) and also to the selective determination of semicarbazide in the presence of hydrazine in several synthetic mixtures containing different concentration ratios of semicarbazide and hydrazine.     

The determination of cobalt in cobalt-platinum alloys

The separation and analysis of cobalt-platinum alloys by ion exchange or hydrazine reduction are superior to the usual techniques of hydrogen sulfide precipitation or base metal reduction. Cobalt is determined by controlled potential electrodeposition.     

Heteroadamantanes and their derivatives

1-p-nitrophenyl-3,6-diazahomoadamantane and 1-p-nitrophenyl-3,6-diazahomoadamantan-9-one were obtained by nitration of 1-phenyl-3,6-diazahomoadamantane and 1-phenyl-3,6-diazahomoadamantan-9-one with a mixture of potassium nitrate and sulfuric acid; 1-p-nitrophenyl-3,6-diazahomoadamantan-9-one was reduced with sodium borohydride to 1-p-nitrophenyl-3,6-diazahomoadamantan-9-ol. It was found that the nitro groups of these nitrophenyldiazahomoadamantanes were reduced to amino groups by heating with hydrazine hydrate without a catalyst. 1-p-Aminophenyl-3,6-diazahomoadamantan-9-one was obtained by reduction of nitrophenyl-azahomoadamantanone with tin in sulfuric acid, and 9-amino-1-p-aminophenyl-3,6-diazahomo-adamantane was obtained by reduction of its oxime with a nickel—aluminum alloy in water—base medium.See [1] for 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1257–1261, September, 1992.     

One-step double reduction of aryl nitro and carbonyl groups using hydrazine

Single-step reduction of aryl nitro and carbonyl groups to the corresponding synthetically useful alkyl-anilines occurs with excellent yields by treatment with hydrazine and a base in a solvent-free reaction. The method has been applied to a broad range of compounds with different properties. Investigations into the mechanism of the reduction reveal that each group is reduced independently. A mechanism is proposed for this novel reduction of aromatic nitro groups.     

Heteroadamantanes and their derivatives. 23. Reduction of nitroaryl derivatives of 3,6-diazahomoadamantane

It has been found that nitroaryl derivatives of diazahomoadamantane can be reduced selectively by hydrazine. New data are presented on the noncatalytic reduction of p-nitrophenyldiazahomoadamantane by hydrazine hydrate.For Communication 22 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1405–1408, October, 1993.     

Reduction of iodate by hydrazine: Application of the iodide ion selective electrode to the uncatalyzed reaction

Summary The reduction of iodate by hydrazine was examined by use of the iodide ion selective electrode. The rate of reduction of iodate at iodide concentrations below 5 × 10^–5 M is controlled by the direct reduction by hydrazine. At higher iodide concentrations, the rate of reduction of iodate is controlled by the reduction of iodate by iodide with the subsequent reduction of iodine by hydrazine. Application of the reaction to the determination of g quantities of iodine is discussed.

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Zusammenfassung Die Reduktion von Jodat mit Hydrazin wurde mit Hilfe einer jodid-spezifischen Elektrode untersucht. Das Ausmaß der Jodatreduktion bei Jodid-konzentrationen unter 5·10^–5 Mol/l wurde durch direkte Reduktion mit Hydrazin kontrolliert. Bei höheren Jodidkonzentrationen wurde das Reduk-tionsausmaß des Jodats mit Hilfe der Jodat-Jodid-Reaktion und erst dann durch Reduktion des Jodids mit Hydrazin kontrolliert. Die Anwendung auf die Bestimmung von g-Mengen Jodid wurde diskutiert.

     

Assay of mixtures of hydrazine and other nitrogen bases by thermometric titrimetry

Summary Binary mixtures of hydrazine and one of the following N-containing bases: ammonia, aniline, hydroxylamine, thiocyanate and unsymmetrical dimethyl hydrazine have been assayed thermometrically. The titrations are based both on the basic and the reducing properties of the compounds. For example, whilst for mixtures of hydrazine and ammonia, the total base content is determined by an acid/base titration, and the hydrazine component is determined by oxidation with bromate ion; for mixtures containing aniline or hydroxylamine, serial titration with bromate ensures that all the hydrazine is oxidised before the onset of oxidation of the other component. Mixtures of hydrazine and UDMH have been assayed in both aqueous and non-aqueous media and a comparison of results has been reported. The main advantage of the proposed methods is that they can be applied to industrial samples, which would render other methods impossible.

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Analyse von Mischungen des Hydrazins mit anderen Stickstoff-haltigen Basen durch thermometrische Titration

Zusammenfassung Binäre Mischungen von Hydrazin mit Ammoniak, Anilin, Hydroxylamin, Thiocyanat und asymmetrischem Dimethylhydrazin wurden thermometrisch analysiert. Sowohl die basischen als auch die reduzierenden Eigenschaften des Hydrazins bilden die Grundlage der Titrationen. Zum Beispiel wird im Gemisch Hydrazin/Ammoniak der Gesamtbasengehalt acidimetrisch ermittelt und die Hydrazinkomponente durch Oxydation mit Bromat bestimmt. Im Gemisch Anilin/Hydrazin oder Hydroxylamin/Hydrazin wird mit Bromat zunächst alles Hydrazin oxydiert, bevor die Oxydation der zweiten Komponente einsetzt. Mischungen von Hydrazin mit asym. Dimethylhydrazin werden in wäßrigem und auch in nichtwäßrigem Medium ausgeführt und die Ergebnisse verglichen. Der Hauptvorteil der beschriebenen Verfahren besteht darin, daß auch industrielle Proben untersucht werden können, bei denen andere Verfahren versagen würden.

     

Functionalization of graphene with electrodeposited Prussian blue towards amperometric sensing application

Prussian blue (PB) was grown compactly on graphene matrix by electrochemical deposition. The as-prepared PB-graphene modified glassy carbon electrode (PB-graphene/GCE) showed excellent electrocatalytic activity towards both the reduction of hydrogen peroxide and the oxidation of hydrazine, which could be attributed to the remarkable synergistic effect of graphene and PB. The PB-graphene/GCE showed sensitive response to H₂O₂ with a wide linear range of 10-1440 μM at 0.0 V, and to hydrazine with a wide linear range of 10-3000 μM at 0.35 V. The detection limit was 3 μM and 7 μM, respectively, and both of them had rapid response within 5 s to reach 95% steady state response. The wide linear range, good selectivity and long-time stability of the PB-graphene/GCE make it possible for the practical amperometric detection of hydrogen peroxide and hydrazine.     

Hydrosulfite reduction of N-nitroso-1,2,3,4-etrahydroisoquinolines and oxidation of N-amino-l,2,3,4 tetrahydroisoquinolines

The sodium hydrosulfite reduction of N-nitroso-1,2,3,4-tetrahydroisoquinoline ( 5 ) does not result in the loss of nitrogen and leads to the corresponding hydrazine 6 which upon oxidation with mercuric oxide in ethanol at 62° gives the hexahydrotetrazine 7 in 39% yield. Treatment of the N-tosyl derivative of 6 with base affords 7 in nearly quanitative yield. Oxidation of 6 in 1-butanol at 95° results in the formation of a complex product mixture from which only one component, 1,1′-azobis-3,4-dihydroisoquinoline ( 8 ) could be isolated. Surprisingly the sodium hydrosulfite reduction of 2-nitroso-3-phenyl-1,2,3,4-tetrahydroisoquinoline ( 15 ) also failed to proceed with loss of nitrogen and yields the corresponding hydrazine 16 . However, 16 was cleanly oxidized by mercuric oxide in ethanol at 62° with concurrent elimination of nitrogen to afford 2-phenylindane in 75% yield. Possible rationalizations for these results are presented.     

Heterocyclic nitro compounds

Depending on the conditions and nature of the hydrazine derivative, the reaction of 1-methyl-3,5-dinitro-1,2,4-triazole (I) with hydrazine leads either to the replacement of one of the nitro groups by a hydrazine residue or to its reduction to an amino (hydroxylamino) group. In both cases, the reaction takes place in position 5 of the triazole ring. The reaction of I with acetylhydrazine gives 5-azido-1-methyl-3-nitro-1,2,4-triazole.For Communication V, see [11].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 7, pp. 997–1000, July, 1970.     

Platinum catalyzed reduction of uranium(VI) with hydrazine in sulfuric acid media

The process of platinum-catalyzed uranium(VI) reduction with hydrazine in sulfuric acid media has been studied. The influence of sulfuric acid and hydrazine concentrations, and temperature on the reaction rate were investigated. A new reaction mechanism is proposed. The process allows to obtain pure U(IV) sulfate solutions with concentrations of up to 0.3 mol·l^–1. Further increase of initial U(VI) concentrations is limited by the reductant solubility in sulfuric acid media.     

Reduction of 2-amino-3- and -5-nitropyridine derivatives with hydrazine hydrate

The reactions of 2-amino-3-nitropyridine and 2-amino-5-nitropyridine with hydrazine hydrate resulted in elimination of the amino group and reduction of the nitro group with formation of 3-aminopyridine. A probable reaction mechanism involves addition of hydrazine hydrate at the N-C² bond, followed by elimination of ammonia and reduction of the nitro group to amino. 2-Amino-4-methyl-3-nitropyridine and 2-amino-5-methyl-3-nitropyridine reacted with hydrazine hydrate in a similar way.     

An amperometric sensor for hydrazine based on nano-copper oxide modified electrode

A sensitive hydrazine sensor has been fabricated using copper oxide nanoparticles modified glassy carbon electrode (GCE) to form nano-copper oxide/GCE. The nano-copper oxide was electrodeposited on the surface of GCE in CuCl₂ solution at −0.4 V and was characterized by Scanning electron microscopy and X-ray diffraction. The prepared modified electrode showed a good electrocatalytic activity toward oxidation of hydrazine. The electrochemical behavior of hydrazine on nano-copper oxide/GCE was explored. The oxidative current increased linearly with improving concentration of hydrazine on nano-copper oxide/GCE from 0.1 to 600 μM and detection limit for hydrazine was evaluated to be 0.03 μM at a signal-to-noise ratio of 3. The oxidation mechanism of hydrazine on the nano-copper oxide/GCE was also discussed. The fabricated sensor could be used to determine hydrazine in real water.     

Cross‐Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate‐Determining Deprotonation of Bound Hydrazine

Reported here is the Pd‐catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate‐limiting deprotonation of a hydrazine‐bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.     

The possibility of catalytic hydrogenation of nitrogen in solutions

Conclusions It was shown that hydrogen can be used for the reduction of nitrogen to hydrazine in aqueous alcohol medium.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 196–197, January, 1973.     

Solvent effect on the size of platinum nanoparticle synthesized in microemulsion systems

In this research work, the effect of solvent on the size of paltinum nanoparticles synthesized by microemulsion method was investigated. Platinum nanoparticles have been prepared by the reduction of H₂PtCl₆ with hydrazine in water-in-oil (w/o) microemulsions consisting of sodium bis(2-ethylhexyl) sulfo-succinate (AOT) and solvents n-hexane, cyclohexane and n-nonane. The size of the platinum nanoparticles was measured using transmission electron microscopy (TEM). It was verified that, for reduction of H₂PtCl₆ by hydrazine in microemulsion with different organic solvents, the solvents are arranged by their influence on nanoparticle sizes as follows: n-nonane > cyclohexane > n-hexane.     

Heteroadamantanes and their derivatives. 17. Wolff—Kishner reduction of 3,6-diazahomoadamantan-9-ones

Wolff—Kishner reduction of the keto group of 3,6-diazahomoadamantan-9-ones to a methylene group was investigated. It was shown that diazahomoadamantanones yield hydrazones in the reaction with hydrazine hydrate, and they are converted into 3,6-diazahomoadamantane derivatives with one or two substituents in nodal positions when heated with a base. Unsubstituted 3,6-diazahomoadamantane is not formed in these conditions, since 3,6-diazahomoadamantan-9-one hydrazone is convened into azine when heated above 70C. Other hydrazones are also converted into azines when heated, but at a higher temperature —above 150C.See [1] for Communication 16.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 653–657, May, 1992.     

Nickel(II) chelates of Schiff bases derived from isatin and chromone with amino acids and substituted hydrazines

Summary Nickel(II) complexes of the Schiff base derivatives of isatin with glycine, -alanine, anthranilic acid, S-methyl hydrazine carbodithioate, the ammonium salt of hydrazine carbodithioate, thiosemicarbazide, and benzoyl hydrazine, and nickel(II) complexes of 6-formyl-7-hydroxy-5-methoxy-2-methyl chromonelideneS-methyl hydrazine carbodithioate and benzoyl hydrazone, were prepared and characterized by elemental analysis, i.r., u.v.-vis spectra and magnetic measurements. All the complexes are octahedral.     

Multiple detection for hydrazine based on reduction of the 1,6,7,12-tetrachloroperylene diimide derivative

In this contribution, the 1,6,7,12-tetrachloroperylene diimide derivative (TClPDIs) with first reduction potential of ? 0.0117 V was chosen for detection of hydrazine based on colorimetric probe, fluorescence quenching and chemical sensor. Interaction of TClPDIs with hydrazine in N,N-dimethylformamide lead to a red shift in the maximum absorption and fluorescence quenching as a result of reduction. Consequently, the yellow TClPDIs solution transform to green, the linear range of the determination of hydrazine was 0.317–2.895 nmol (R² = 0.989) for colorimetric detection. Furthermore, the linear range of determination for hydrazine based on fluorescent quenching of TClPDIs was 0.645–3.57 nmol with a correlation coefficient R² = 0.986. Thin film devices of TClPDIs with different thickness (20, 40 and 60 nm) deposited on interdigital electrodes were chosen to study the sensitive detection and quantification of organic amine vapors by monitoring the changes of its current intensity under ambient conditions. This chemical sensor showed different sensitivity towards different organic bases. These results indicated that the TClPDIs is a favorable candidate for the detection of hydrazine using reduction mechanism.     

Reaction of N-amino-4,6-dimethylpyrimidinium mesitylene sulfonate with nucleophiles . A 15n-study

Reaction of N-amino-4, 6-dimethylpyrimidinium mesitylene sulfonate with liquid ammonia, with an aqueous solution of sodium hydroxide or with hydrazine leads to 3, 5-dimethylpyrazole. Reaction of this salt with ¹⁵N-labelled hydrazine gave incorporation of nitrogen-15 in 3,5-dimethylpyrazole and in recovered starting material. Evidence has been presented that the initial step in the ring contraction with hydrazine is the addition of the nucleophile to C-2 and C-6. It is suggested that in the presence of a base the reactive species is probably 4,6-dimethylpyrimidinio amide.