Methyl hydrocarbons

In a search for allelopathic agents from common weeds, Amaranthus palmerl S. Wats (Palmer amaranth) and Ambrosia artemisiifolia L. (Louisiana annual ragweed) have been analysed for their organic natural products. From A. palmerl phytol, chondrlllasterol, vanillin, 3-methoxy-4-hydroxynitrobenzene and 2,6-dimethoxy- benzoquinone were isolated. From the roots of Ambrosia artemisiifolia four polyacetylenes, a mixture of sesquiterpene hydrocarbons, methyl caffeate, and a mixture of 8-sitosterol and stlgmasterol were obtained. 

Basically, the Rf value of a solute is determined by its distribution ratio which in turn is dependent on relative solubilities for partition systems or relative polarities for adsorption systems. For example, if adsorption TLC is used to separate a mixture of squalene (a hydrocarbon), methyl oleate, cholesterol and a-tocopherol (vitamin E), then squalene, being the least polar, will move furthest and the cholesterol, being the most polar, will remain close to the origin. Methyl oleate is less polar than a-tocopherol and will therefore be found between it and the squalene. The role of polarity is discussed more fully on p. 82. 

Solutions of Solid Fuels in Liquid Hydrocarbons — Methylated PCU Alkene Dimers... 

Upon oxidizing ethene, propene, or isobutene together with aldehydes, alkylated aromatic hydrocarbons, methyl ethyl ketone or other... 

A hydrocarbon is negligibly soluble in water, but, equally well, water is insoluble in the hydrocarbon. Methyl alcohol is soluble in water in all proportions, but not in a hydrocarbon. A higher alcohol is only slightly soluble in water, but is freely soluble in hydrocarbons. Water and hydrocarbons, so far as their solubilities are concerned, are opposites what is soluble in one is insoluble in the other. Thus,... 

Polyaromatic hydrocarbons Methyl chloride, n-pentane, ethyl ether, acetone, acetonitrate 7 PAHs studied [212]... 

Oxygenated derivatives of hydrocarbons Methyl-branched ketones... 

Quantitative changes in lipid compounds on the silk and cuticle of females correlate significantly with changes in female sexual receptivity in spiders. For example, female T. atrica attach a contact sex pheromone to their web (Trabalon et al., 1997,2005 Prouvost et al., 1999). This pheromone consists of a complex mixture of saturated hydrocarbons, methyl esters (methyl tetradecanoate, methyl pentadecanoate, methyl hexadecanoate, and methyl octadecanoate) and their fatty acids (tetradecanoic, pentadecanoic, hexadecanoic, and cis,cis-9,12-octadecadienoic acids). The female uses cuticular compounds, which are applied to the silk in substantial amounts during web construction. Modification of chemical profiles makes the female attractive to males (Trabalon et al., 2005). Receptive females are different to unreceptive ones with respect to three fatty acids (hexadecanoic, octadeca-dienoic and octadecenoic acids) and three methyl esters (linoleate, oleate, and stearate) present on both the web and the cuticle. Our combined results from chemical analyses and behavioral assays demonstrate clearly that these contact compounds are quantitatively correlated with the behavior of spiders. 

Biosynthesis of Insect Hydrocarbons Methyl-branched Components. 

Polar hydrocarbons Methyl furan/methyl tetra-hydrofuran 0.61 Intalox 0.038 14.63 0.53 101... 

Halogenated alkyl, aryl or alkylaryl oxides Halogenated hydrocarbons Methyl alcohol (methanol)... 

Fig. 4.31 Biodegradation pathways of hydrocarbon. Methyl-oxidation, by attack of the methyl group (-CH3) at the extremity of the hydrocarbon chain, results in formation of a carboxylic acid group (-COOH). P-oxidation indicates that oxidation occurs at the second carbon atom (counted from the end that bears the -COOH group, the a-carbon atom being immediately adjacent to the -COOH group). P-oxidation continues removing C2 units, and in effect unzips the hydrocarbon chain until it no longer exists.

Either individually or in combination, these are excellent catalysts for oxidation of aromatic hydrocarbons (methyl groups) to aldehydes and acids. 

The cis-isomer that is shown is the natural sex pheromone of the gypsy moth. Disparlure is an aliphatic hydrocarbon (methyl-octadecan) with an epoxy group. It is used as an attractant and is formulated in plastic flakes. The racemic mixture may also be used. 

Figure 2 presents ethylene conversion at 250 C as a function of thermal pretreatment given to a sample at different temperatures. In case of both the ZSM-5 (Si/Al=40,80) samples used in this study, the ethylene conversion was affected only marginally when the san )le pretreatment temperature was in range 300-700 C (curves a,b. Fig. 2). On the contrary, the catalytic activity of HZSM-5 sample showed an increase with the rise in pretreatment temperature from 300 to 700°C (Fig. 2c). Further rise in the pretreatment temperature to 900°C resulted in the reduced activity of all the three zeolite samples. The product distribution showed a significant change as a function of pretreatment in the case of HZSM-5 zeolite while the effect was only marginal for the improtonated ZSM-5 sample. These data are shown in Fig.3. As seen in Fig.3, the rise in the pretreatment temperature to 700°C resulted in the progressively reduced yields of C3-C5 hydrocarbons (particularly propene, butane, butene, pentene, hexene and benzene) whereas the selectivity for C7-C8 hydrocarbons (methyl cyclohexene, toluene, octane and octene) increased significantly. No such change in the selectivity was observed in the case of improtonated ZSM-5 samples(Fig. 3b).

The purification of the exhaust gas of PTA plants is one application where halohydrocarbon destruction catalysts have found use at a global scale (12, 13, 17, 18). Typically the untreated exhaust contains a mixture of volatile organic components including methyl bromide, carbon monoxide, hydrocarbons, methyl acetate, and organic acids. The presence of the methyl bromide sets forth the requirement that a catalyst such as the HDC be used. Additionally, the catalyst must be able to effectively destroy all the other organic components (with their widely different intrinsic reactivities toward air oxidation) of the mixture at reasonably low temperatures. Currently most PTA offgas remediation catalysts are used at an inlet temperature higher than 350°C. An improvement of catalyst activity is desired to... 

DIPROPILENTRIAMINA (Spanish) (56-18-8) see 3,3 -iminodipropylamine. DI-w-PROPYLALUMINUM HYDRIDE (2036-15-9) Extremely flammable liquid. The pure material ignites spontaneously in air. Violent reaction with water. A powerful reducing agent. Violent reaction with oxidizers, alcohols, carbon dioxide, cresols, halogens, halogenated hydrocarbons, methyl ether, nitrogen oxides, phenols, sulfur oxides, tetrahydrofuran and many other materials. Store under inert gas, away from all other materials. Commercial product may be a 15 to 30% solution in hydrocarbons. See also next entry. 

Ourisson reported that the main constituents of hypericum essential oils are represented by hydrocarbons (methyl-2-octane and n- nonane), monoterpenes (limonene, a- and p-pinene), and sesquiterpenes (8-caryophyllene). The relative content of limonene has been taken as a diacritic character to divide the genus into two groups one including sections with a high content of limonene (> 10%), and the other comprehensive of plant sections containing less than 5% of limonene in their essential oils, Fig. (2) [17]. 

Recent patents describe the use of solvents to improve the properties of agricultural chemicals. In one invention, a carrier was developed from an agglomerated composition of plant fibers and mineral filler. The purpose of the carrier is to absorb and hold a large quantity of pesticide until it is delivered to the application site. The pesticide must be in a form of low melting liquid. In order to reduce its melting point, solvents selected from aromatic hydrocarbons are used to dissolve pesticide. In a water dispersible composition of insecticide, solvent is used to convert insecticide to a liquid form at room temperature. Solvents proposed for this application are from a group of aUcyl aromatic hydrocarbons, methyl esters of alkanoic acids, and ester mixtures derived from plant oils. 

Poly(acrylic acid) Water, dil. alkali, methanol, DMF Hydrocarbons, methyl acetate, acetone... 

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