Showing papers on "Hexane published in 1974"
TL;DR: In this paper, Pd and Pd-Au alloys were studied for hydrogenation of acetylene and reactions of hexane, and the results showed that the changes in the population of the transition metal orbitals cannot alone be responsible for the variations in the kinetic parameters and product distributions.
44 citations
TL;DR: In this article, the influence of various solvents (water, methanol, diethyl ether, n -hexane, cyclohexane) and of the excitation energy (λ exc ) on the fluorescence quantum yield (Q F ) of phenol has been investigated in O 2 - free solutions.
34 citations
TL;DR: In this paper, a detailed investigation of the formation of n-R 2 Mg compounds in hydrocarbon solvents in the absence of organic base is reported, including information on the nature of the solutions formed and by-products, the effect of the alkyl halide, the hydrocarbon solvent and temperature of formation.
33 citations
22 citations
TL;DR: In this article, the radical stabilization energy of the cyano group was shown to be about 7.3 kcal/mol, compared with the reported rates of isomerization of bicyclo[2.2.0] and 4-Dicyanobicyclohexadiene-1, 5 (3).
Abstract: 1, 4-Dicyanobicyclo[2.2.0]hexane (2) was prepared by (2+2)-photocycloaddition of ethylene to 1, 2-dicyanocyclobutene. 2 isomerizes cleanly to 2, 5-dicyanohexadiene-1, 5 (3) with a very low activation energy of 21.7 ± 1.4 kcal/mol. From comparison with the reported rates of isomerization of bicyclo[2.2.0]hexane, the radical stabilization energy of the cyano group is shown to be about 7.3 kcal/mol.
21 citations
Patent•
10 May 1974
TL;DR: Hexane and mixtures of hexane containing 2 to 25% acetic acid (v/v) were used to prepare oil and protein from glanded cottonseed by solvent extraction as mentioned in this paper.
Abstract: Hexane and mixtures of hexane containing 2 to 25% acetic acid (v/v) were used to prepare oil and protein from glanded cottonseed by solvent extraction. As the amount of acetic acid in the solvent increased, the amounts of total lipid, phospholipid, neutral oil, and gossypol in each miscella increased, but the amount of free fatty acids did not change significantly. The solubility of the protein in 0.02N NaOH did not decrease until the amount of acetic acid in the solvent used to prepare each meal increased to a point between 4 and 10 percent. The drainage of the miscella (solvent-lipid solution) through the marc (insoluble residue) was much more rapid when the solvent was hexane-acetic acid than when it was hexane alone.
10 citations
TL;DR: N-Methylpyrrole reacts with n-butyl-lithium in hexane to give mainly 2,4- and 2,5-dianions whose relative proportions depend upon quantities of reagents and reaction times as discussed by the authors.
Abstract: N-Methylpyrrole reacts with n-butyl-lithium in hexane to give mainly 2,4- and 2,5-dianions whose relative proportions depend upon quantities of reagents and reaction times.
9 citations
TL;DR: Hexane and mixtures of hexane and 2-25% acetic acid (v/v) were used to prepare oil and protein from glanded cottonseed by solvent extraction as discussed by the authors.
Abstract: Hexane and mixtures of hexane and 2–25% acetic acid (v/v) were used to prepare oil and protein from glanded cottonseed by solvent extraction. As the amount of acetic acid in the solvent increased, the amounts of total lipid, phospholipid, neutral oil, and gossypol in each miscella increased, but the amount of free fatty acids did not change significantly. However, the solubility of protein in 0.02N NaOH decreased as the amount of acetic acid in the solvent used to prepare each meal increased. Other aspects of using acidified hexane are described.
8 citations
Patent•
05 Sep 1974TL;DR: In this paper, a process for recovering hexane from the mixed recycle stream from a plurality of ethylene polymerization reactors is described, where all of the hexane is recovered as an overhead azeotrope containing about 57% hexane.
Abstract: A process is provided for recovering hexane from the mixed recycle stream from a plurality of ethylene polymerization reactors. The recycle stream containing hexane and periodically vinyl acetate and/or an alkyl acrylate admixed with vinyl acetate to provide a mixed feed stream containing at least 45% by weight vinyl acetate. This feed stream is distilled at atmospheric pressure and all of the hexane is recovered as an overhead azeotrope containing about 57% hexane. The overhead fraction is redistilled at a superatmospheric pressure of at least 4 atmospheres in a second column. The overhead fraction of the second column will be enriched in vinyl acetate and pure hexane is recovered as a bottoms fraction from the second column. The vinyl acetate and/or alkyl acrylate contained in the bottoms fraction of the first column is recovered by atmospheric distillation in a third column.
7 citations
TL;DR: In this article, the ternary mixture n-hexane + cyclohexane+ benzene was calculated from the experimentally determined total vapor pressures and liquid compositions by means of both direct and indirect methods.
7 citations
TL;DR: In this paper, the composition dependence of the work function of mixtures of neopentane and tetramethyl silane with n-hexane was predicted using a pseudo-one-component fluid model and the theory of Springett, Jortner and Cohen.
TL;DR: In this article, acidified hexane (hexane containing 2−25% acetic acid, v/v) was extracted from cottonseed tissue and examined with an electron microscope.
Abstract: Cottonseed tissue was extracted with acidified hexane (hexane containing 2–25% acetic acid, v/v) and then examined with an electron microscope. In all cases, the contents of the oil-rich spherosomes were emptied and cytoplasm remained intact after lipid extraction. However, membranous elements of the cytoplasm appeared diffuse and disorganized. The possible effect of this disorganization of membranes in accounting for the greater amount of lipid extracted by acidified hexane than by hexane is discussed.
TL;DR: In this paper, the gas-phase decomposition of 6-oxabicyclo[3,1,0]hexane has been studied over the temperature range 670-742 K at pressures between 1 and 28 Torr Isomerization.
Abstract: The kinetics of the gas-phase decomposition of 6-oxabicyclo[3,1,0]hexane have been studied over the temperature range 670–742 K at pressures between 1 and 28 Torr Isomerization to cyclopentanone and cyclopent-2-en-1-ol accounts for ∼97 % of the primary reaction products and occurs by first-order, homogeneous, non-radical processes kcyclopentanone/s–1= 101416∓011 exp(– 240 400∓1500/8314T), kcyclopent-2-en-1-ol/s–1= 101356∓016 exp(– 242 200∓2200/8314T)
TL;DR: In this paper, the authors compared the results obtained in n -pentane and n -hexane with those obtained in liquid n -heptane and showed that the three distributions of the dimerization products are consistent with a mechanism of formation of the Dimers through addition of two thermalized radicals.
TL;DR: The photolysis of 2,4,4-trimethyl-4-sila-3-methylene-1,6-heptadiene was found to be photochemically non-reactive under identical reaction conditions, and the 1-substituted butadienes (VI) and (VIII) underwent cis-trans isomerism on photolyisation as discussed by the authors.
TL;DR: In this article, the sesquiterpene tree was extraeted with acetone and the residue was extracted with hexane and, after concentration, was subjected to chromatography on an alumina column (selvent: n-hexane containing 200/e ethylacetate) and then on a siliea gel column, to isolate 9-oxenerolidol (1), cis-and trans-3, 7, 11-trimethyldo-decq-1,7, 10-trien-3-ol-9rt
Abstract: Leaves of the sesquiterpene tree3, one kind of camphor tree, were extraeted with acetone. The extract, after concentration, was treated with hexane and the hexane solution was steam distilled in order to remove the volatile substances. The residue was extracted with hexane and, after concentration, was subjected to chromatography on an alumina column (selvent: n-hexane containing 200/e ethylacetate) and then on a siliea gel column (solventin-hexane cpntaining 150/o ethylaeetate), to isolate 9-oxenerolidol (1), cis- and trans-3, 7, 11-trimethyldo- decq-1, 7, 10-trien-3-ol-9rt-one (2), (3), 9-oxofarnesol (4) and its acetate(5).The structure of each. go-mpoynq was tested by spectral qpd chemical analyses. The stereochemistry of 9-oxonerolidol, which was a major compound was determined as in (1) in relation to (+)in-nerolidol.
Patent•
07 Nov 1974
TL;DR: In this paper, a carrier gas is selected from methane, ethane, propane, butane and oils such as fuel oil, kerosine, hexane, heptane and octane and the lining is pref.
Abstract: The hydrocarbon is selected from methane, ethane, propane, butane and oils e.g. such as fuel oil, kerosine, hexane, heptane and octane and their derivatives. They may be used in a carrier gas and the lining is pref. a binder-free or low binder-content refractory.
TL;DR: In this article, the reaction of n-hexane and methylcyclopentane over polycrystalline platinum films evaporated in a ultrahigh vacuum condition, the initial distribution of reaction products varied with the reaction temperature and the hydrogen/hydrocarbon ratio.
Abstract: In the reaction of n-hexane and methylcyclopentane over polycrystalline platinum films evaporated in a ultrahigh vacuum condition, the initial distribution of reaction products varied with the reaction temperature and the hydrogen/hydrocarbon ratio. The effect of the reaction conditions was interpreted as depending on the possible reaction mechanisms cited.
TL;DR: In this paper, the reaction of n-hexane and methylcyclopentane over polycrystalline platinum films evaporated in a ultrahigh vacuum condition, the initial distribution of reaction products varied with the reaction temperature and the hydrogen/hydrocarbon ratio.
Abstract: In the reaction of n-hexane and methylcyclopentane over polycrystalline platinum films evaporated in a ultrahigh vacuum condition, the initial distribution of reaction products varied with the reaction temperature and the hydrogen/hydrocarbon ratio. The effect of the reaction conditions was interpreted as depending on the possible reaction mechanisms cited.
TL;DR: In this article, the gas-phase decomposition of 6-oxabicyclo[3,1,0]hexane has been studied over the temperature range 670-742 K at pressures between 1 and 28 Torr.
Abstract: The kinetics of the gas-phase decomposition of 6-oxabicyclo[3,1,0]hexane have been studied over the temperature range 670–742 K at pressures between 1 and 28 Torr. Isomerization to cyclopentanone and cyclopent-2-en-1-ol accounts for ∼97 % of the primary reaction products and occurs by first-order, homogeneous, non-radical processes. kcyclopentanone/s–1= 1014.16∓0.11 exp(– 240 400∓1500/8.314T), kcyclopent-2-en-1-ol/s–1= 1013.56∓0.16 exp(– 242 200∓2200/8.314T)
TL;DR: In this paper, the radical chain isomerization of aliphatic ketone mercaptals under the influence of tert-butyl peroxide has been studied and both possible migration paths of the thiol groups are realized in the case of 2, 2-bis(n)-butylthio)hexane and 2,2-bis (n- butylthios)butane.
Abstract: The radical chain isomerization of aliphatic ketone mercaptals under the influence of tert-butyl peroxide has general significance. Both possible migration paths of the thiol groups are realized in the case of the unsymmetrical mercaptals of 2, 2-bis(n-butylthio)hexane and 2,2-bis(n-butylthio)butane, with the formation of both 1,2-bis(n-butylthio)alkanes and 2,3-bis(n-butylthio)alkanes.