Showing papers on "Aromatic hydrocarbon published in 1977"

Synchronous fluorescence spectroscopy and its application to indigenous and petroleum-derived hydrocarbons in Lacustrine sediments

Abstract: A comparison of conventional fluorescence emission spectra and spectra produced by synchronously scanning both excitation and emission monochromators is made on a series of standard oils to demonstrate the increased resolution achieved by the synchronous technique. Greater information on the aromatic content of the oils is obtained by separating the aromatic hydrocarbon fractions by liquid-solid column chromatography prior to fluorescence analysis. Fluorescence spectroscopy, in particular the synchronous method, is used to characterize the indigenous and petroleum-derived aromatic hydrocarbons in sediments of Lake Washington, Wash.

Chemically initiated electron exchange luminescence. A new chemiluminescent reaction path for organic peroxides

Abstract: : The thermal decomposition of diphenoylperoxide in the presence of certain aromatic hydrocarbons generates benzocoumarin and light corresponding to the fluorescence spectrum of the hydrocarbon. It is shown that this chemiluminescence does not result from conventional energy transfer from some electronically excited peroxide decomposition product to the aromatic hydrocarbon. Instead, the chemiluminescence is initiated by electron transfer from the hydrocarbon to the peroxide followed by rapid decarboxylation and back electron transfer to form the electronically excited hydrocarbon. The yield of light from this process is quite high. It is suggested that a similar mechanism may be operating in several previously described chemiluminescing systems. (Author)

The bay-region theory: a quantum mechanical approach to aromatic hydrocarbon-induced carcinogenicity

Abstract: Publisher Summary This chapter presents the bay-region theory as a quantum mechanical approach to aromatic hydrocarbon-induced carcinogenicity. The bay-region theory is a prediction both of biological activity and chemical reactivity. Recent studies have been designed to test the theory for the hydrocarbon benzo[a]anthracene. In an experiment described in the chapter, five metabolically possible trans-dihydrodiols of the hydrocarbon were synthesized to examine the ability of a highly purified and reconstituted cytochrome P-448 system to metabolize them to compounds mutagenic toward bacteria. As a substrate for the formation of mutagens, the 3,4-dihydrodiol was found to be 10 times more active than the other dihydrodiols or the parent hydrocarbons. Because the 3,4-dihydrodiol can form bay-region epoxides at the 1,2-position, which were predicted to be the most reactive, the quantum mechanical predictions are borne out. Similar support for the bay-region concept has been found through metabolic activation of dihydrodiols from benzo[a]-pyrene. As anticipated, dihydrodiols from smaller hydrocarbons such as naphthalene, anthracene, or phenanthrene could not be activated to produce significant numbers of mutations.

Separation of aromatic hydrocarbons from mixtures, using polyurethane membranes

Abstract: A process for separating an aromatic hydrocarbon of the general formula ##STR1## wherein R represents an alkyl group having 1 to 3 carbon atoms and n is 0, 1, 2, or 3 (and wherein the groups R, when n is 2 or 3 can be the same or different), From a mixture comprising said compound and one or more aliphatic hydrocarbon, cycloaliphatic hydrocarbon, alcohol, ether, ketone or a carboxylic acid ester which comprises contacting said mixture with a polyurethane membrane.

Experimental measurements of phase equilibrium properties for systems containing n-heptane, benzene, N-methylpyrrolidone, and monoethanolamine. Representation by the NRTL equation

Abstract: The separation of aromatic and saturated hydrocarbons is performed on a large scale in industry for the recovery of pure aromatic hydrocarbons from petroleum fractions. These separations are achieved by various techniques, which often require the addition of a solvent (extractive distillation, liquid-liquid extraction). The design of separation processes requires experimental information on phase equilibria and related thermodynamic properties. The determination of many thermodynamic data describing a quaternary system of two solvents and two hydrocarbons is also of theoretical interest for testing the qualities of the representation of these experimental quantities by a model of solution. Excess enthalpies (9, liquid-liquid equilibrium data (3, vapor-liquid equilibrium data ( 7, 6, 78) of mixtures of n-heptane, benzene, and two solvents, N-methylpyrrolidone (NMP) and monoethanolamine (MEA), were measured to complement the data already available in the literature cited. NMP is one of the industrially accepted solvents for aromatic hydrocarbon separation, it is sometimes used in a mixture with another solvent.

Relationships of quantum mechanical calculations, relative mutagenicity of benzom anthracene diol epoxides, and “bay region” concept of aromatic hydrocarbon carcinogenicity

Abstract: Evidence supporting the conclusion that 7,8‐dihydroxy‐9,10‐epoxy‐7,8,9,10‐tetra‐hydrobenzo[a]pyrenes are ultimate mutagenic and carcinogenic forms of benzo[a]‐pyrene (BP) is summarized. Quantum mechanical calculations that predict reactivity of diol epoxides derived from BP and other polycyclic aromatic hydrocarbons are described. The calculations predict that diol epoxides in which the oxirane ring forms part of a “bay region” of a tetrahydrobenzo ring should be the most reactive for a given aromatic hydrocarbon. Experiments with dihydrodiols and diol epoxides from benzo[a]anthracene (BA) are described. The ability to metabolically activate BA 3,4‐dihydrodiol to species much more mutagenic than those obtained from other BA dihydrodiols and the much greater mutagenicity of the diastereoisomeric 3,4‐diol‐1,2‐epoxides of 1,2,3,4‐tetrahydro BA relative to other diol epoxides of BA are in accord with predictions of the quantum mechanical calculations.

Method for producing cyclohexane derivatives directly from aromatic hydrocarbons

Abstract: Cyclohexane derivatives such as cyclohexanol and cyclohexyl carboxylates are produced directly from aromatic hydrocarbons. The reaction may be carried out, under hydrogenation conditions, by reacting an aromatic hydrocarbon with hydrogen and a reagent selected from the group consisting of water, and carboxylic acids in the presence of a strong acid and a hydrogenation catalyst.

Hydrocarbon soluble straight-chain di-(lower alkyl) magnesium compositions

Abstract: A composition of matter comprising di-n-butylmagnesium and diethylmagnesium with a n-butyl:ethyl alkyl group ratio of about 0.25:1 to about 4:1 which is soluble in aliphatic, cycloaliphatic, and aromatic hydrocarbon solvents is disclosed. The composition is prepared in the substantial absence of oxygen and moisture by the simultaneous or consecutive reactions of ethyl and n-butyl halides with metallic magnesium in the presence of the hydrocarbon solvent, followed by separation of the insoluble magnesium chloride and any unreacted magnesium metal from the resulting solution.

Hydroalkylation composition and process for producing said composition

Abstract: An aromatic hydrocarbon is contacted under hydroalkylation conditions and in the presence of hydrogen with a composition comprising at least one platinum compound supported on a calcined, acidic, nickel and rare earth-treated crystalline zeolite which additionally has a halide content sufficient to promote the selectivity of the composition to produce a desired cycloalkyl aromatic hydrocarbon.

Analysis of the polycycllic aromatic hydrocarbon content of airborne particulate pollutants in a Søderberg paste plant

Abstract: A method of enrichment and separation of polycyclic aromatic hydrocarbons (PAH) in air samples is described. Airborne particulate samples from the work atmosphere of a Soderberg carbon-paste plant were collected on glass fiber and Acropor filters using high volume samplers. The filters were Soxhlet-extracted using cyclohexane and extractable matter was subject to a liquid/liquid separation. The PAH-fraction was concentrated and separated on a gas chromatographic system with the possibility of mass spectrometric identification. More than 40 PAH compounds and some heterocyclic compounds having from 3 — 6 rings have been separated and identified. Quantitative determinations show that some of the PAH-components are 2 — 3 decades more abundant than recently reported data from urban air samples. The results are presented as a PAH-profile. It is suggested that the PAH-profile may be a characteristic of the process involved. Furthermore, the profile has a potential use of the profile in evaluating potentially haz...

Asphaltic compositions containing conjugated diene-monovinyl-substituted aromatic hydrocarbon copolymers of particular structures

Abstract: An asphaltic composition having low temperature flexibility and resistance to stress cracking, shearing or adhesive failure is prepared using conjugated diene-monovinyl substituted aromatic hydrocarbon copolymers prepared in absence of polar-type randomizers, e.g., tetrahydrofuran, or by incremental addition of both the monovinyl substituted aromatic hydrocarbon and initiator, e.g., organomonolithium. The composition is especially useful in cold places, e.g., as a coating for objects to be stored or kept in cold ground, above ground or under the sea.

Generation of Ketocarbenoid by α-Elimination of ω,ω-Dibromoacetophenone with Copper, and Trapping by Cycloaddition to Olefins

Abstract: Ketocarbenoid was generated by the reaction of ω,ω-dibromoacetophenone with copper in aromatic hydrocarbon, and was trapped by cycloaddition to olefins. This is the first example of cyclopropanation of olefins by formally divalent carbon intermediate without use of diazoketones.

Method of making novel rubbery block copolymers and pressure-sensitive adhesives

Abstract: Rubbery coupled conjugated diene/monovinyl-substituted aromatic hydrocarbon teleblock copolymers are prepared by incremental addition of both monovinyl-substituted aromatic hydrocarbon and initiator. The resulting copolymers can be used to produce improved pressure-sensitive adhesives.

The Fate of Aromatic Hydrocarbons in Photochemical Smog Systems: Toluene

Abstract: For the first time a satisfactory carbon mass balance is reported for the reaction of an aromatic hydrocarbon in a photochemical smog system. Approximately 96% of the reacted aromatic hydrocarbon (toluene) is accounted for as reaction products. The products of the reaction indicate three different mechanisms of formation of primary products including (1) side chain attack, (2) ring cleavage, and (3) addition to the ring. A fourth mechanism involves secondary reaction of the primary products. In terms of mathematical modeling of photochemical smog, it is imperative that the primary products of the aromatic hydrocarbons be incorporated in kinetic models and the secondary reactions of these products taken into account, since reaction products such as the aldehydes are probably more reactive in photochemical smog systems than the aromatic hydrocarbon starting material.

N-sulfonylimidazoles as peroxygen activators

Abstract: A process of removing soil and/or stains from fabrics by immersing the fabrics in a peroxygen bleach bath containing as a peroxygen activator an N-sulfonylimidazole of the formula: ##STR1## wherein R2, R3 and R4 are each selected from the class consisting of hydrogen, halogen, alkoxy of 1 to 16 carbon atoms, carbonylmethoxy, nitro, an aliphatic hydrocarbon radical of 1 to 16 carbon atoms, a cycloaliphatic hydrocarbon radical of 3 to 7 carbon atoms, an aromatic hydrocarbon radical of the benzene and naphthalene series and a heterocyclic radical of 1 to 2 rings each containing 5 to 6 members of which 1 to 2 are heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur while taken together R3 and R4 can complete a benzene ring and R1 is a hydrocarbon or heterocyclic radical as above defined for R2, R3 and R4. Also described are dry blend compositions containing the bleach bath components.

Method of producing 1,2-polybutadiene

Abstract: Butadiene polymers containing 70% or more of 1,2-structure and a relatively low melting point are produced by polymerizing 1,3-butadiene in the presence of a catalyst which has been prepared by admixing (A) an organic solvent solution containing 1,3-butadiene, a cobalt compound and an organoaluminium compound; (B) an amide compound of the formula (2) or (3): ##STR1## wherein R 1 , R 2 and R 3 are respectively an H atom, aliphatic hydrocarbon radical of 1 to 7 carbon atoms or aromatic hydrocarbon radical of 6 or 7 carbon atoms, R 3 is H or an aliphatic hydrocarbon radical of 1 to 3 carbon atoms and n is 2 to 5, and; (C) carbon disulfide

Catalysts for isocyanate polyaddition reactions

Abstract: This invention relates to new catalyst combinations having improved catalytic activity for isocyanate polyaddition reactions. The catalysts are combinations of known metal catalysts with aromatic compounds which contain at least one nitrogen atom as a hetero atom and have at least one primary amino group in the ortho- or para-position to the hetero atom. Preferred aromatic compounds include ##STR1## wherein R 1 , R 2 , R 3 and R 4 which may be the same or different, each represent a hydrogen atom, an aliphatic hydrocarbon group having from 1 to 6 carbon atoms or an aromatic hydrocarbon group having from 6 to 12 carbon atoms or two of the groups R 1 to R 4 represent a condensed aromatic ring.

Cyclic-substituted derivatives of 1-amino-2-propanol

Abstract: Compounds of the formula ##STR1## WHEREIN Ar 1 and Ar 2 denote an optionally substituted aromatic hydrocarbon radical or a monocyclic, monoazacyclic or diazacyclic radical of aromatic character and Alk represents lower alkylene, or salts thereof, exhibit β-receptor-blocking, blood pressure-lowering and vasodilatory effects and are useful for example in the treatment of arrythmias and angina pectoris, and as blood pressure-lowering agents.

Process for nitrating aromatic hydrocarbons

Abstract: An improved process for the nitration of aromatic hydrocarbons is described. The aromatic hydrocarbon (benzene, toluene of particular interest) is reacted with gaseous nitrogen dioxide in the presence of a catalytic amount of sulfuric acid and in the absence of oxygen. The process is highly selective and avoids the formation of undesired by-products. The acid employed as catalyst can be recovered and recycled after removal of water of condensation liberated in the reaction.

Aromatic sulfonic anhydrides as peroxygen activators

Abstract: A process of removing soil and/or stains from fabrics by immersing the fabrics in a peroxygen bleach bath containing as a peroxygen activator an aromatic sulfonic anhydride of the formula RSO2 --O--SO2 R, wherein each R is an aromatic ring system selected from the class consisting of a phenyl group, taken together an o-phenylene group, a naphthyl group, taken together an o-naphthylene group and a heterocyclic group having 1 ring or 2 fused rings, said ring or rings containing 5 to 6 members of which 1 to 2 are heteroatoms selected from the class consisting of nitrogen, oxygen and sulfur, said groups optionally bearing 1 to 3 substituents selected from the class consisting of nitro, alkyl of 1 to 16 carbon atoms, alkoxy of 1 to 16 carbon atoms, aliphatic carboxamido of 1 to 16 carbon atoms, benzamido, chlorine and bromine. Aromatic is used herein in its modern sense to signify an organic ring system having aromatic character including both aromatic hydrocarbon and heterocyclic ring systems. Also described are dry blend compositions containing the bleach bath components.

Preparation of cycloolefin

Abstract: PURPOSE: To prepare a cyclolefin in a high yield with ease, by partial hydrogenation of an aromatic hydrocarbon, using a catalyst containing ruthernium and one or two or more types selected from Ti, Zr, V, Ta, Cd, and Hg. COPYRIGHT: (C)1979,JPO&Japio

C8 Alkyl aromatic hydrocarbon isomerization by recycling benzene and toluene

Abstract: An improved C 8 alkyl aromatic hydrocarbon isomerization process comprising the steps of (1) contacting the feedstock with an isomerization catalytic composite in the presence of hydrogen at isomerization conditions to isomerize at least a portion of the C 8 alkyl aromatic hydrocarbons and to produce an effluent; (2) separating the effluent to form a hydrogen-rich gaseous fraction, a first hydrocarbon-rich fraction containing toluene and having a lower average molecular weight relative to C 8 alkyl aromatic content, and a second fraction enriched in C 8 alkyl aromatic content relative to the effluent; provided that at least a portion of the first hydrocarbon-rich fraction is subjected to the contacting of step (1); and (3) recovering at least one C 8 alkyl aromatic product from the second fraction. Improved yields of specific desired C 8 hydrocarbon isomers and more efficient and complete C 8 alkyl aromatic isomerization are among the benefits obtained.

Aromatic nitrile prepd. from hydrocarbon and hydrogen cyanide - in hydrofluoric acid; used as intermediates for optical brighteners, textile auxiliaries, pharmaceuticals and plant protecting agents

Abstract: Prepn. of aromatic nitriles is carried out by (a) reacting an aromatic hydrocarbon with HCN in >=90 wt. % HF acid at room tempo. or above, and (b) hydrolysing the resulting aldimine with an aw. mineral acid. The prods. are useful as intermediates for optical brighteners, dyes, textile auxiliaries, pharmaceuticals and plant protection agents. The process gives high yields (e.g. up to 92%) without the use of catalysts or organic solvents (cf. standard Gatt ermann reaction). In an example, 2,4-dimethyoxybenzaldehyde is prepd. from resorcinol dimethyl ether.

Fire resistant functional fluid compositions based on phosphate esters and substituted aromatic compounds

Abstract: Functional fluid composition comprising an ester of a phosphorus acid and a compound of the formula I r(ch.sub.2 x).sub.n (I) in which R represents an aromatic hydrocarbon or heterocyclic containing residue, n is an integer of at least 2, and each X is the same or different and represents a leaving group, which composition may be used for a wide variety of purposes, for example in hydraulic machinery employed in foundries and mines, in hydraulic systems for aircraft, in turbines and as fluids in electrical equipment and in heat transfer devices.

Ion recombination processes in rigid solutions

Abstract: It is known that the free ion yield is small in irradiated aromatic hydrocarbon liquids. This study uses pulse radiolysis to observe anions of aromatic solutes in matrices at 77 K. In aliphatic matrices, trapped electrons tunnel to aromatic solutes and the anion yield is observed to grow with time. If the concentration of aromatic solute is large (0.1 M) or if the matrix is aromatic, ion recombination via tunneling dominates the anion kinetics, and long lived triplet states are observed to grow in. These results and the effects of other charge scavengers indicate that just a few percent of added aromatic material can dramatically increase the probability of charge recombination in aliphatic media, and that this effect involves decreased charge separation distances. The same effect apparently also occurs in alkane liquids at room temperature.

Filled, thermoplastic workholding composition including a dicarboxylic acid, an alkylene hydrocarbon polymer, and an aromatic hydrocarbon polymer

Abstract: There is provided an improved thermoplastic hot-melt composition for use in encapsulating a workpiece, e.g. a jet engine airfoil or blade. The composition comprises a filled, normally solid resinous material which contains as an organic moiety, a blend of a dimeric fatty acid containing from 32 to 40 carbon atoms, a C5 -C6 alkylene hydrocarbon polymer, and a nonpolar aromatic hydrocarbon polymer, said blend having dispersed therein a minor amount of an alkyl cellulose ether. A method of encapsulating a workpiece with such a composition is also disclosed.

Benzodioxolan derivatives, process of making the same and herbicidal composition containing same

Abstract: Benzodioxolan derivatives of the formula ##STR1## wherein R1 and R2 are the same or different and are hydrogen, an aliphatic hydrocarbon residue, a halogenated aliphatic hydrocarbon residue, an aromatic hydrocarbon residue, a substituted aromatic hydrocarbon residue, A heterocyclic residue or a substituted heterocyclic residue, Or wherein R1 and R2 together with the adjoining carbon atom are a cycloaliphatic hydrocarbon residue which may additionally be substituted by nitrogen or oxygen or both, and wherein R3 is hydrogen or an aliphatic hydrocarbon residue, And wherein R4 is a saturated or unsaturated aliphatic hydrocarbon residue or is alkoxy and wherein R5 is hydrogen or is a saturated or unsaturated aliphatic hydrocarbon residue. The compounds have a high herbicidal activity against weeds and superior selective herbicidal properties for agricultural and horticultural plantations. The invention also embraces processes for making the compounds and compositions containing the same.