Showing papers on "Reducing agent published in 1975"

Effects of reducing and oxidizing agents on the action of bleomycin

Abstract: The effects of reducing agents, such as 2-mercaptoethanol, dithiothreitol, L-ascorbic acid, or sodium borohydride, and oxidizing agents, such as hydrogen peroxide or dehydroascorbic acid, on the in vitro action of bleomycin were investigated. After the incubation of DNA with a low concentration of bleomycin and a reducing or oxidizing agent, single strand breaks were mainly caused in the DNA molecules. The degradation of DNA was largely prevented by the removal of oxygen, or by the addition of divalent cations or of S-(2-aminoethyl)isothiuronium bromide hydrobromide, a radical scavenger, to the incubation mixture. Preincubation of bleomycin with these reducing or oxidizing agents reduced the DNA-degrading activity of the antibiotic. However, this reduction in activity was observed even in the absence of oxygen, or in preincubation mixture supplemented with radical scavenger.

Process for the continuous production of an ethylene/vinyl acetate copolymer dispersion

Abstract: A process for the continuous manufacture of an aqueous ethylene/vinyl acetate copolymer dispersion which comprises continuously copolymerizing ethylene and vinyl acetate and optionally other α-olefinically unsaturated monomers, in an aqueous emulsion in the presence of an emulsifier and/or a protective colloid, and in the presence of a free-radical-forming redox catalyst system of a reducing agent and an oxidizing agent as well, optionally, as a heavy metal salt, and recovering said ethylene/vinyl acetate copolymer dispersion, characterized by (a) the presence of a molar excess of at least 3 times, preferably from 3 to 10 times, said reducing agent over said oxidizing agent dosed into the reaction medium and (b) adding the monomers continuously to the reaction mixture at such a rate that the concentration of unreacted monomers at no place in the reaction zone exceeds 15% by weight of the total weight of the reaction mixture.

Catalyst preparative method

Abstract: C 4 vanadium - phosphorus oxidation catalysts for producing maleic acid are prepared in an aqueous phosphoric acid solution using a reducing agent comprising an organic acid or aldehyde and a secondary alcohol such as oxalic acid and ethanol in a mole of 1:1 to 3 respectively, in which an inorganic vanadium compound such as V 2 O 5 is dissolved and reduced to vanadium of 5 + valency or less.

Aqueous gelable compositions having extended gelation time and methods of preparing same

Abstract: Aqueous gelable compositions comprising water, a polymer, a polyvalent metal compound wherein the metal can be reduced to a lower polyvalent valence state, a reducing agent, and a complexing agent for complexing with newly reduced ions of said metal and increasing the gelation time of said compositions; and methods of preparing said compositions.

Intramolecular electron transfer

Abstract: In most of the oxidation-reduction reactions involving net electron transfer which have been studied, the experimental results yield only second order rates, and thus reflect the barrier to bringing reactants together as well as that for the electron transfer act itself. Recent advances in synthetic procedures make it possible to measure as an intramolecular or first order process, net electron transfer in complexes containing Co(III) and Ru(II) as oxidizing and reducing agents respectively for a wide variety of bridging groups. Systems in which the bridging groups mediate in electron transfer, as well as others, in which the bridging groups serve only to define the separation of the oxidizing agent and reducing centres become accessible to study. In a somewhat related class of reactions, a particular ligand in an oxidizing complex is converted by external means to a reducing agent, and the rate of reduction of the oxidizing metal ion by the damaged ligand is measured, as a first order process. Closely related in principle to the work referred to are studies on mixed valence complexes such as Figure options Download full-size image Download as PowerPoint slide where electron transfer between a ruthenium (II) and a ruthenium (III) end can be considered. But the two classes differ dramatically because in the latter system there is no chemistry associated with electron transfer, in the sense that no bonds are broken or formed on electron transfer. The mixed valence complexes in fact require different experimental approaches for their study and feature elements of interest different from those exhibited by the Co(III)-Ru(II) class. The principles underlying the behaviour of the class of molecules will be outlined, and the results obtained in the study of their properties are described.

Heat developable light-sensitive material incorporating a substituted s-triazine-2,4,6-(1H, 3H, 5H)-trione reducing agent

Abstract: A heat developable light-sensitive material having reduced fog, increased whiteness, and stability to normal room illumination comprising a support having therein or in one or more layers thereon (a) an organic silver salt, (b) a light-sensitive silver halide or a component capable of forming a light-sensitive silver halide upon reaction with the organic silver salt (a), and (c) as a reducing agent an s-triazine-2,4,6-(1H, 3H, 5H)-trione substituted with a phenol derivative (having a substituted group in at least one of the o-positions thereof with respect to the hydroxyl group) in at least one of the 1-, 3- or 5-positions.

Gel formation by polymer crosslinking

Abstract: A composition of matter comprising water, a polymer capable of being crosslinked by polyvalent metal cations, a reducible species containing said polyvalent metal in a higher oxidation state, and a reducing agent selected from among KI, MnCl 2 , Mn(NO 3 ) 2 , and K 4 Fe(CN) 6 which composition is capable of forming a gel by crosslinking is provided. A method is also provided for in situ gel formation using this crosslinking composition. In one of its embodiments a method is provided for increasing the rate of gel formation by the addition of H+ ion.

Light production in alkaline mixtures of reducing agents and dimethylbiacridylium nitrate

Abstract: — Kinetic studies were made of light production and 02 absorption elicited by treatment of dimethylbiacridylium hydroxide [D(OH)2] with reducing agents in alkaline aqueous solutions. D(OH)2 addition stimulated O2 uptake which proceeded with zero-order kinetics until nearly all of the O2 or of the D(OH)2 was converted to end products. At the termination of the reactions with fructose as reductant the D(OH)2 was converted to methylacridone and to dimethylbiacridene each compound accounting for approximately one-half the D(OH)2 consumed. O2 was reduced to H2O2. With hydroxylamine as the reducing agent the emitted light intensity was related to the first power of the D(OH)2 concentration and the rate of O2 uptake to the square root of the D(OH)2. The disappearance of D(OH)2 in these circumstances was by a first order or pseudo-first order rate. Fructose as a reducing agent by contrast resulted in an O2 uptake nearly independent of D(OH)2 concentration over a range from 1 × 10-5M-1 × 10-4M, while the light intensity and disappearance of D(OH)2 followed a one-half order rate. O2 uptake was by zero order kinetics and the oxidation of fructose proceeded at the same rate as was found with ferricyanide as oxidant. The kinetics, quantum yields and temperature dependence of the fructose reactions were compared with similar reactions employing H2O2 as the light eliciting reagent. The results are interpreted as indicating that D(OH)2 acts as a chain initiator in a manner analogous to better known, radical producing compounds found to accelerate hydrocarbon autooxidations.

Stable photo-sensitive polymer layers for holography

Abstract: Stable red-sensitive layers consisting of methylene blue, acrylamide, and a reducing agent have been prepared. The reducing agent can be a sodium salt of p-toluene-sulphinic acid or dimedone, dissolved in the polymers gelatin or polyvinyl alcohol. A simple method for characterizing the effect of light at 633 nm on the layers, in terms of refractive index changes and of surface relief formation, is described. The application of the layers in spatial filtering is proposed.

Preparation of hydrogen fluoride with low levels of arsenic, iron and sulfite

Abstract: A process for preparing pure anhydrous hydrogen fluoride with decreased levels of arsenic, iron and sulfite by treating anhydrous hydrogen fluoride sequentially with an oxidizing agent, and then a heavy metal free reducing agent, distilling the resulting mixture and recovering the pure hydrogen fluoride.

Production of aluminum chloride

Abstract: A method for producing aluminum chloride comprises contacting Al2 O3 with a reducing agent and chlorine in a bath of molten metal halides to form aluminum chloride and recovering the aluminum chloride by vaporization.

Fluid separation process and membrane

Abstract: There is described an improved separation membrane-liquid barrier system of the type containing complex-forming, metal-containing ionic components, and an improved separation process in which the membrane-liquid barrier is employed. The membrane is in contact with an aqueous liquid barrier containing cuprous ions, such as a cuprous salt or a cuprous salt complex, e.g. a CuCl complex, preferably a CuCl--NH 4 Cl--HCl complex, and the barrier is in contact with a reducing agent that retards the complexing Cu + ion from being oxidized to Cu + 2 . The reducing agent is relatively stable when positioned in the membrane and is not unduly oxidized by air nor does it unduly interfere with the essential function of the cuprous ions during the separation process. Elemental copper may function as a reducing agent that retards oxidation of Cu + ion to Cu + 2 . The liquid barrier containing complex-forming cuprous ions can be subjected to a strong reducing agent during the separation process to reduce some of the cuprous ions to elemental copper.

Mechanism of cytochrome c peroxidase. O-benzoylhydroxylamine as an analog of hydrogen peroxide.

Abstract: A number of reagents, some of which are electronic analogs of hydrogen peroxide, will replace it in the reactions of cytochrome c peroxidase These compounds include N-bromosuccinimide, sodium hypochlorite, and the novel oxidizing agent O-benzoylhydroxylamine If fragments of the oxidant played a functional role in the structure of the oxidized form of the enzyme, it would be expected that the product formed from O-benzoylhydroxylamine would differ from that formed from hydrogen peroxide The products formed on reaction of the two oxidizing agents with cytochrome c peroxidase are indistinguishable This results carries implications for the structure of the so-called ES compound The extension in the range of specific substrates for cytochrome c peroxidase allows identification of the structure which compounds must possess to be oxidizing substrates for the enzyme A mechanism for the first step of the reaction is suggested O-Benzoylhydroxylamine is also a reducing agent, and its reaction with the enzyme is analogous to that of hydrogen peroxide with catalase The final product of the reaction is the inert nitric oxide complex of ferrous cytochrome c peroxidase

Nox reducing agent feeding apparatus

Abstract: PURPOSE: In an apparatus for reducing NOx in gas by feeding a NOx reducing agent into combustion gases, the NOx reducing agent is continuously fed, in required volume, into desired portions of the high temperature combustion gas. COPYRIGHT: (C)1977,JPO&Japio

2-Thiouracil in heat-developable light-sensitive materials

Abstract: A heat-developable light-sensitive material which comprises a support containing therein or in one or more layers thereon at least (a) an organic silver salt; (b) a light-sensitive silver halide or a component capable of forming a light-sensitive silver halide on reaction with the organic silver salt; (c) a reducing agent, and (d) a 2-thiouracil.

Time-lapse free-radical polymerizable composition

Abstract: A time-lapse free-radical polymerizable composition which comprises (1) a free-radical polymerizable compound such as an ethylenically unsaturated monomer or a reactive polymer; (2) a soluble polymerization initiator such as a diacyl peroxide, a ketone peroxide; an alkyl peroxy ester, a dialkyl peroxide, or an inorganic persulfate; (3) a soluble, reducible metal chelate such as an iron or copper chelate in which the chelating agent is a β-dicarbonyl compound having an enol content of at least 4 percent and a dicarbonyl angle of not greater than 120°, or a β-hydroxy nitrogen-heterocyclic fused aromatic in which the hydroxyl group is attached to a carbon beta to the nitrogen in an adjacent ring; (4) a soluble organic reducing agent which is capable of reducing ferric ions to ferrous ions or cupric ions to cuprous ions; and (5) excess chelating agent in the amount of 10 - 4 to 2.5 moles of excess chelating agent per mole of reducible metal chelate. The length of the time-lapse before onset of polymerization can be controlled by the amount of excess chelating agent present without affecting the rate of polymerization once polymerization is initiated.

1-N-alkyl-aminoglycoside-XK-88 derivatives and methods for their manufacture

Abstract: 1-N-Alkyl-Aminoglycoside-XK-88 derivatives, valuable as antibacterial agents, are prepared by the reaction of an acid addition salt of the corresponding 1-N-unsubstituted-Aminoglycoside-XK-88 antibacterial derivative or of a 2"-N-alkanoyl-Aminoglycoside-XK-88-5 derivative in an inert solvent, preferably a protic solvent containing water, with one equivalent of a hydride-donor reducing agent and with at least one equivalent of an aldehyde. The 2"-N-alkanoyl-Aminoglycoside-XK-88-5 intermediates are prepared by the reaction of a partially neutralized acid addition salt of Aminoglycoside-XK-88-5 with an acylating agent, and isolating the 2"-N-alkanoyl-Aminoglycoside-XK-88-5.

Process for the production of sprayed phosphate coats on iron and steel

Abstract: In the process for applying a phosphate coating to a ferric surface which comprises spraying an aqueous acidic solution at a pH of 4.3 to 6.5 containing an orthophosphate salt of a cation selected from the group consisting of alkali metals and ammonium, in the presence of oxidizing agent or reducing agent accelerators onto said surface, the improvement consisting of adding to said aqueous acidic solution from 0.05 to 1 gm per liter of a short-chain alkylolamine having from 2 to 4 carbon atoms in each alkylol and from 0.01 to 1.5 gm per liter of at least one non-ionic surface-active wetting agent.

Heat developable light-sensitive oxazoline containing element

Abstract: A heat developable light-sensitive element having reduced thermal fogging and improved light stability comprising a support having therein or in one or more layers thereon (a) an organic silver salt, (b) a light-sensitive silver halide or a compound capable of forming a light-sensitive silver halide upon reaction with the organic silver salt, (c) a reducing agent, and (d) an oxazolinone compound.

Reduced copper catalyst on support

Abstract: For making supported copper catalyst, useful in hydration of nitriles to produce amides, a cuprous compound e.g. cuprous chloride is impregnated into a support material, e.g. alumina, using acrylonitrile or acetonitrile as the imbibing solvent which is then removed by evaporation. The cuprous compound in the support is reduced to copper in situ, by contact with a reducing agent e.g. sodium borohydride.

Solid supported catalysts for catalytic reduction of nitrogen oxides in waste gases

Abstract: Solid supported catalysts for catalytic reduction of nitrogen oxide in waste gases utilizing ammonia as the reducing agent, the catalyst comprising at least one metallic oxide, sulfate or phosphate of a first transition metal supported on an alumina or silica-alumina carrier; the carrier containing from 0.03 to 20% by weight sulfur, based on the weight of the carrier, calculated as a sulfate or sulfite radical.

Heat-developable light-sensitive materials using the reaction product of a organic silver salt an a N-halo-oxazolidinone

Abstract: A heat-developable light-sensitive material comprising a support having therein or in one or more layers thereon an organic silver (b) a light-sensitive silver halide, and (c) a reducing agent, with the light-sensitive silver halide comprising the reaction product of a part of the organic silver salt and an N-halo compound represented by the following formula (I): ##STR1## wherein R 1 , R 2 , R 3 and R 4 each is a hydrogen atom; an alkyl group having 1 to 22 carbon atoms; a haloalkyl group having 1 to 22 carbon atoms; an amino group; a hydroxyalkyl group having 1 to 22 carbon atoms; an allyl group; a naphthyl group; a benzyl group; a ##STR2## group in which R 5 is a hydrogen atom, a halogen atom, an alkyl group, an alkylthio group, an amino group or an alkylamino group; a benzyloxy group; an aryl group; a haloaryl group; an alkylaryl group; and alkoxyaryl group; an --OR 6 group in which R 6 is a hydrogen atom, an alkyl group, an allyl group, an aryl group or an alkoxyaryl group; a ##STR3## group in which R 7 and R 8 each is a hydrogen atom, an alkyl group, an aryl group or an allyl group; a cyclohexyl group; a --CH 2 OR 9 group in which R 9 is a naphthyl group; or a --CH 2 R 10 in which R 10 is a morpholino group, a piperadino group or an alkylthio group; and X is a chlorine atom or a bromine atom.

Selective removal of nitrogen oxides from waste gas

Abstract: A process for the removal of nitrogen oxides from a waste gas containing said oxides in conjunction with sulfur oxides which comprises contacting said waste gas with ammonia as a reducing agent at temperatures of from 250° to 550° C in the presence of a catalyst wherein an active component containing iron or copper as the active metal and a sulfate of aluminum are supported on a silica carrier.

A method for reduction of nitrogen oxides in exhaust gas

Abstract: PURPOSE: Provision of a reducing agent allowing progression of selective reducing reaction of NO without using catalysts even in the presence of oxygen. COPYRIGHT: (C)1976,JPO&Japio

Physical development of pd(ii) photosensitive complexes with a leucophthalocyanine dye and a reducing agent therefor

Abstract: A process for the formation of phthalocyanine dye images employing palladium nuclei to catalyze the reduction of a leucophthalocyanine to the phthalocyanine dye image by a reducing agent.