Showing papers on "Hydrazine published in 1995"
TL;DR: In this paper, the catalytic activity in the reduction of NO by ammonia in the presence of oxygen (SCR process) is reported for CuO-TiO2 and for different catalysts belonging to the MgO-Fe2O3 system.
385 citations
TL;DR: In this article, the rate of the reaction between hydrazine and Mo(VI in the presence of hydrochloric acid was measured spectrophotometrically at 710 nm.
93 citations
TL;DR: These inhibitor biosensors hold great promise for field-based monitoring of various hydrazines and their inhibitory effect on the activity of immobilized tyrosinase is modeled as a reversible competitive inhibition.
Abstract: An amperometric biosensor for the determination of hydrazine compounds, based on their inhibitory effect on the activity of immobilized tyrosinase, has been developed. The hydrazine-tyrosinase interaction can be modeled as a reversible competitive inhibition. Kinetic parameters (K{sub i} and I{sub 0.5}) have been determined for various hydrazine compounds. The tyrosinase-based carbon paste electrode offers sensitive measurements to the low-micromolar level and good precision. The trend in sensitivity, methylhydrazine > hydrazine >dimethylhydrazine, reflects the degree of inhibition. The applicability to assays of unaltered river and drinking water samples is illustrated. Analogous measurements at disposable thick-film sensors are also reported. These inhibitor biosensors hold great promise for field-based monitoring of various hydrazines. 13 refs., 5 figs.
80 citations
Journal Article•
TL;DR: Estimation of derivatives of 2,4-dinitrophenyl hydrazones in tissues may serve as a pattern of protein oxidative modification during oxidative stress in the body.
Abstract: A rate of protein oxidative destruction may be estimated from the reaction of the resultant carbonyl derivatives of amino acids reaction with 2,4-dinitrophenyl hydrazine. The procedure for estimation of 2,4-dinitrophenyl hydrazones was modified for clinical application. The initiating effect of nonenzymatic components (Fe(3+)-ascorbic acid, Fe(2+)-O2, Fe(2+)-H2O2) was in the metal-catalyzing oxidation of proteins. Estimation of derivatives of 2,4-dinitrophenyl hydrazones in tissues may serve as a pattern of protein oxidative modification during oxidative stress in the body.
67 citations
64 citations
57 citations
TL;DR: Starting from readily available methyl 5-methyloxazole-4-carboxylate (1) and 4-methyl-5-oxazolylcarboxylic acid hydrazide (2) the title compounds were prepared as discussed by the authors.
48 citations
TL;DR: In this article, a Nafion/ruthenium oxide pyrochlore (Pb 2 Ru 2-x Pb x O 7-y )-modified glassy carbon electrode exhibits excellent electrocatalytic activity in the oxidation of hydrazine in neutral media.
Abstract: A Nafion/ruthenium oxide pyrochlore (Pb 2 Ru 2-x Pb x O 7-y )-modified glassy carbon electrode exhibits excellent electrocatalytic activity in the oxidation of hydrazine in neutral media. The catalyst is synthesized directly inside the Nafion thin film matrix, which is spin coated onto a glassy carbon electrode. Hydrazine is detected by flow injection analysis at the modified electrode with excellent sensitivity. Linear calibration curves are obtained over the 5×10 -5 -6×10 -7 M range with pH 8.0 ammonia-ammonium chloride buffer solution as the carrier. The detection limit is 0.048 ng. The practical analytical utility is illustrated by selective flow injection measurements of hydrazine in the presence of oxalic acid and surface-active materials
44 citations
35 citations
TL;DR: The Vilsmeier-Haack reaction of 3β-acetoxyandost-5-en-17-one (1) with phosporous oxychloride and dimethylformamide gave 3β -acetoxy17-chloro-16-formylandrosta-5,16-diene (2) as discussed by the authors.
30 citations
TL;DR: Anhydrous hydrazine is isolated in a pure state as a stable inclusion complex crystal with hydroquinone or p-methoxyphenol, the X-ray structures of which have been analysed as mentioned in this paper.
Abstract: Anhydrous hydrazine is isolated in a pure state as a stable inclusion complex crystal with hydroquinone or p-methoxyphenol, the X-ray structures of which have been analysed; the solid-state reaction of the hydrazine inclusion complex and esters gives hydrazides which are virtually uncontaminated with acid hydrazine salt byproducts.
TL;DR: In this paper, the authors used Auger electron spectroscopy and X-ray photoelectron spectrography to analyze transition metal nitride films with an oxide impurity and showed that the most likely sources of oxygen contamination were incomplete oxide removal during pre-cleaning, water impurities in the hydrazine, and oxygen and water contamination of the films after completion of the nitridation process.
TL;DR: A linear, dynamic detection range for hydrazine has been obtained from 1 to 2000 ppb in air, with an instrument response that is fully reversible and achieves plateau response in less than 2 min.
TL;DR: The use of β-diketones with strong electron-withdrawing substituents in reaction with hydrazine and its monosubstituted derivatives leads to the stable intermediates of pyrazole synthesis.
TL;DR: A variety of heterocyclic compounds have been prepared by the reaction of dicyanoketene ethylene acetal with 1,3-dipolar reagents arenecarbonitrile oxides (2) and further reactions with hydrazine and its derivatives as mentioned in this paper.
TL;DR: Several hydrazinium (1 +) and dicarboxylates of aliphatic and aromatic carboxylic acids have been prepared by neutralisation of these acids with hydrazine hydrate in aqueous medium as discussed by the authors.
Patent•
18 Aug 1995TL;DR: In this article, an improved method to produce Group III nitride thin film having a lower defect density was proposed, which consisted of combining under metalorganic chemical vapor deposition (MOCVD) conditions at least one Group III metalorganic compound with ammonia, hydrazine, nitrogen-hydrogen, or combinations thereof in a molar ratio of between about 1/10000 and 2/1 of metalorganic to the ammonia.
Abstract: The present invention relates to an improved method to produce Group III nitride thin film having a lower defect density, which method comprises: (a) combining under metalorganic chemical vapor deposition (MOCVD) conditions at least one Group III metalorganic compound with ammonia, hydrazine, nitrogen-hydrogen, or combinations thereof in a molar ratio of between about 1/10000 and 2/1 of metalorganic to the ammonia, hydrazine, nitrogen-hydrogen, or combinations thereof, at a low pressure of about 100 torr or less, to produce a first nitride layer; (b) combining under metalorganic chemical vapor deposition conditions at least one Group III metalorganic compound with ammonia, hydrazine, nitrogen-hydrogen, or combinations thereof in a molar ratio of between about 1/10000 and 2/1 of metalorganic to the ammonia, hydrazine, nitrogen-hydrogen, or combinations thereof, at a high pressure of about 700 to 760 torr or greater for between about 5 and 60 min to produce a nitride layer having a reduced defect density and; (c) repeating steps (a) and (b) to produce a Group III metal nitride having a reduced defect density of less than half of the defects observed wherein high and low pressure cycling is not used.
Patent•
21 Feb 1995TL;DR: In this article, the authors characterized microcapsules whose walls are made of reaction products of guanidine compounds and polyisocyanates or contain such reaction products, and showed that dispersions containing such micro-capsules can be prepared by replacing the amines, amino alcohols or hydrazine compounds in processes known per se for preparing microcapsule dispersions.
Abstract: Novel microcapsules are characterized in that their walls are made of reaction products of guanidine compounds and polyisocyanates or contain such reaction products. Dispersions containing such microcapsules can be prepared by replacing the amines, amino alcohols or hydrazine compounds in processes known per se for preparing microcapsule dispersions from polyisocyanates and amines, amino alcohols or hydrazine compounds by guanidine compounds. The present invention also relates to no-carbon copy papers containing dyestuff precursors in microcapsules whose walls are made of reaction products of guanidine compounds and polyisocyanates or contain such reaction products.
TL;DR: Alkylation of 3-methylpyrazole with 2-phenethyl p-toluenesulfonate gave 3methyl-1-(2-phenethyltoluene) pyrazole (2a) in low yield.
TL;DR: ProtProtection of the benzylic position of 4methylaminosulfonylmethylphenyl hydrazine 6 with a 4hydroxy-2-methyl-3(2 H )-isothiazolone-1,1-dioxide group allowed the preparation of indole 3 without formation of side-product.
TL;DR: In this paper, the dielectric properties of PECVD SiO2 were improved by reaction with anhydrous hydrazine vapor at 150-350°C, and both silanol and water were removed from the films.
Abstract: The dielectric properties of plasma-enhanced chemical vapor deposition (PECVD) SiO2 deposited at 150°C were improved by reaction with anhydrous hydrazine vapor at 150–350°C. The permittivity and loss decreased ~32% and ~86%, respectively, after reaction with hydrazine at 150°C. The decrease in permittivity and loss correlated with a decrease in the dipole concentration (silanol + water). During exposure to humid conditions, water uptake in the SiO2 films degraded the dielectric properties. A nitrogen anneal at 350°C did not improve the dielectric properties of the PECVD SiO2. Although water was removed from the films, silanol remained. When the PECVD SiO2 deposited at 150° was reacted with hydrazine vapor at 150°C, both silanol and water were removed from the films. The dielectric properties and resistance to water absorption improved.
Patent•
11 May 1995
TL;DR: In this article, a large number of inhibiting agents that are useful to reduce aldol condensation in monoethanolamine scrubbers are presented, such as hydrazine, hydroperoxides, hydrogen peroxide, and dialkylketone oximes.
Abstract: The present invention provides a large number of inhibiting agents that are useful to reduce aldol condensation in monoethanolamine scrubbers. Such agents include hydrazine, hydroperoxides, hydrogen peroxide, and dialkylketone oximes. Preferred inhibiting agents are hydrazines.
Patent•
19 Sep 1995
TL;DR: In this article, an aqueous covering composition is composed of a solution of a vinyl polymer synthesized from 30 to 90wt.C second-order transition temperature, 6000 to 150000 weight-average molecular weight and 35 to 200mg KOH/g acid value.
Abstract: PURPOSE:To obtain an aqueous covering composition capable of forming a coating film excellent in water resistance, weather resistance and abrasion resistance, excellent in dispersion of pigment and prevention of environmental pollution and suitable for an aqueous coating material, etc., by blending a specified aqueous resin dispersion with a specified organic hydrazine derivative. CONSTITUTION:This aqueous covering composition is composed of (A) an aqueous solution of a vinyl polymer synthesized from 30 to 90wt.% methyl methacrylate, 0 to 30wt.% aromatic vinyl compound, 4 to 30wt.% acid group- containing vinyl compound, l to 40wt.% vinyl monomer containing a carboxyl group, etc., and 0 to 65wt.% another vinyl monomer and having 10 to 150 deg.C second-order transition temperature, 6000 to 150000 weight-average molecular weight and 35 to 200mg KOH/g acid value, (B) an aqueous resin dispersion composed of an aqueous dispersion of a urethane-based polymer synthesized by reacting an aliphatic isocyanate, etc., with, e.g. a diol having terminal OH groups and 500 to 5000 number-average molecular weight, neutralizing the resultant urethane prepolymer with a tert-amine and subsequently conducting a chain-lengthening reaction, etc., and (C) an organic hydrazine derivative having two or more hydrazine residues.
Patent•
12 Jul 1995TL;DR: In this paper, a suitable o-nitroazobenzene compound to the corresponding 2-oxybenzotriazole compound was reduced to 2-(2-hydroxyphenyl)-2H-benzotonitriazole using a metal catalyst.
Abstract: 2-(2-Hydroxyphenyl)-2H-benzotriazoles can be prepared particularly advantageously by catalytically reducing a suitable o-nitroazobenzene compound to the corresponding N-oxybenzotriazole compound in the presence of hydrazine hydrate, a metal catalyst selected from the group consisting of Raney-Ni and the noble metals, an organic or inorganic base, an organic solvent, and optionally water; followed by isolating said N-oxybenzotriazole compound and converting it to the corresponding 2-(2-hydroxyphenyl)-2H-benzotriazole.
TL;DR: In this article, various diethyl β-functional γ-oxo alkylphosphonates (3) were conveniently prepared using two complementary inexpensive strategies, and were reacted with hydrazine, methylhydrazine or phenylhydrazines giving regioselectively new dietsyl 1-(pyrazol-4-yl)-alkylphosphonsates (4), isolated in high yields.
01 Jan 1995
TL;DR: Estimation of derivatives of 2,4-dinitrophenyl hydrazones in tissues may serve as a pattern of protein oxidative modification during oxidative stress in the body.
Abstract: A rate of protein oxidative destruction may be estimated from the reaction of the resultant carbonyl derivatives of amino acids reaction with 2,4-dinitrophenyl hydrazine. The procedure for estimation of 2,4-dinitrophenyl hydrazones was modified for clinical application. The initiating effect of nonenzymatic components (Fe(3+)-ascorbic acid, Fe(2+)-O2, Fe(2+)-H2O2) was in the metal-catalyzing oxidation of proteins. Estimation of derivatives of 2,4-dinitrophenyl hydrazones in tissues may serve as a pattern of protein oxidative modification during oxidative stress in the body