Hydrocarbons, hydrocarbon methylene

CeUulose triacetate is insoluble in acetone, and other solvent systems are used for dry extmsion, such as chlorinated hydrocarbons (eg, methylene chloride), methyl acetate, acetic acid, dimethylformamide, and dimethyl sulfoxide. Methylene chloride containing 5—15% methanol or ethanol is most often employed. Concerns with the oral toxicity of methylene chloride have led to the recent termination of the only triacetate fiber preparation faciHty in the United States, although manufacture stiH exists elsewhere in the world (49). 

In addition to its water solubility poly(vinyl pyrrolidone) is soluble in a very wide range of materials, including aliphatic halogenated hydrocarbons (methylene dichloride, chloroform), many monohydric and polyhdric alcohols (methanol, ethanol, ethylene glycol), some ketones (acetyl acetone) and lactones (a-butyrolactone), lower aliphatic acids (glacial acetic acid) and the nitro-paraffins. The polymer is also compatible with a wide range of other synthetic polymers, with gums and with plasticisers. 

An aldehyde or ketone 1 can react with hydrazine to give a hydrazone 2. The latter can be converted to a hydrocarbon—the methylene derivative 3—by loss of Na upon heating in the presence of base. This deoxygenation method is called the Wolff-Kishner reduction. ... 

The character of fuel oil generally renders the usual test methods for total petroleum hydrocarbons (Chapters 7 and 8) ineffective since high proportions of the fuel oil (specifically, residual fuel oil) are insoluble in the usual solvents employed for the test. In particular, the asphaltene constituents are insoluble in hydrocarbon solvents and are only soluble in aromatic solvents and chlorinated hydrocarbons (chloroform, methylene dichloride, and the like). Residua and asphalt (Chapter 10) have high proportions of asphaltene constituents, which render any test for total petroleum hydrocarbons meaningless unless a suitable solvent is employed in the test method. 

Methylene Chloride tdichtaromethane). CAS 75-09-2. As with the other members of the methyl series of chlorinated hydrocarbons, methylene chloride can he produced hy direct chlorination of methane. The usual procedure involves a modification of the simple methane process. The product from Ihe first chlorination passes through aqueous zinc chloride, contacting methanol at about 100 C. Thus. HCl from chlorination is used to displace the alcohol group, producing additional methyl chloride. This is further chlorinated to methylene chloride. Methylene chloride reacts violently in the presence of alkali or alkaline earth metals and will hydrolyze to formaldehyde in the presence of an aqueous base. Alkvlalion reactions occur at both functions, thus di-suhstiiulioiis result. For example. 

Solvents Polish remover contains acetone paint remover, paint thinner, and correction fluids contain toluene (an aromatic hydrocarbon), methylene chloride, and methanol fuel gas contains butane lighter fluid contains butane and isopropane fire extinguishers contain bromochlorodifluo-romethane. 

Water, ethyl acetate, hydrocarbons, methylene chloride... 

Think, for a moment, about the principal role played by the central carbon of a functional group in forming C-C bonds. Then ask how many C-C bonds that particular carbon is capable of forming until it gets rid of all heteroatoms directly substituted on it as well as unsaturations. This number could be anything from a maximum of four, for stable species of carbon, to a minimum of zero in the case of nonactivated hydrocarbon methylenes and methane. Then give this number a name, say Functionality Number, abbreviated as FN. 

Amenable sulfur compounds are reacted with fluorine to produce HF and the chemiluminescence is subsequently measured. Saturated hydrocarbons, methylene chloride, acetonitrile, methanol and carbon tetrachloride give little or no response ... 

The lower stability of tr-alkyl complexes and metallacycloalkanes with larger ring size, which is in contrast to metallacyclopentanes and -hexanes, can be traced to a sterically favorable transition state for / -H transfer, which requires an M—C—C—H dihedral angle of about 0°. Ifin the case of titanacyclopentanes a similar transition state with an M—C—C—C dihedral angle of about 0° is present, a C—C bond cleavage takes place. By a / -H transfer and subsequent ring contraction, ferra- and tantalacyclo-pentanes yield different hydrocarbons and methylene complexes. 

Paints often contain solvents such as toluene, xylene, halogenated aromatic hydrocarbons, and methylene chloride, as well as heavy metals in their pigments including chromium yellow, lemon yellow (barium chromate), vermilion red (cadmium and mercuric sulfides), and flake white (lead). Both acute and chronic exposures to toluene and xylene are associated with neurotoxicity and can also damage the liver and kidneys. 

The addition of HOOH to 2 1 pyridine/acetic acid solutions that contain FeIRPA)2 (PA = picolinate ion) and cyclohexane (C-C6H12) results in the catalyzed transformation of C-C6H12 to cyclohexanone [c-CgHioCO)]. Table 4-5 summarizes the conversion efficiencies and product yields for the oxygenation by the HOOH/Fe(PA)2 combination of several organic substrates (hydrocarbons with methylenic carbons, acetylenes, and aryl olefins). Catalyst turnovers (moles of product per mole of catalyst) are also tabulated. The relative reaction efficiencies for cyclohexane, n-hexane, cyclohexene, and 1,4-cyclohexadiene are roughly... 

Early uses of trichloroethylene included degreasing, and by 1940, a formulation of trichloroethylene named Trilene had widespread use as an anesthetic. Toxicity soon became apparent, especially after cranial nerve injuries and activated latent herpes infections resulted from anesthesia (Defalque 1961 Humphrey and McClelland 1944). Other important halogenated hydrocarbons include methylene chlo-... 

Diazomethane is also used for methylenation under the conditions of diazomethane photolysis. This reaction was first described by Doering et al. [102] and used by Simmons et al. [103] and Dvoretzky et al. [104] to obtain mixtures of hydrocarbons. The methylenation of hydrocarbons is a valuable method for obtaining mbttures of hydrocarbons of specific composition which are used as standard mixtures in GC analysis. The methylenation reaction consists in the homolytic addition of methylene along the... 

Boraadamantanes are readily soluble in chlorinated hydrocarbons (chloroform, methylene chloride, carbon tetrachloride) and in benzene. The parent 1-boraadamantane (5) can be recrystallized from hydrocarbons (pentane), whereas alkyl derivatives are soluble in these solvents. More polar solvents either react or give complexes with 1-boraadamantanes. 

Causes of acute chemical hepatitis include exposure to industrial solvents such as halogenated hydrocarbons (methylene chloride, trichloroethylene, and trichloroethane) carbon tetrachloride (only rarely encountered in modem industry) and dimethylformamide, dinitropropane, and di-methylacetamide. The jet and rocket fuel components hydrazine and monomethylhydrazine are also potent hepatotoxins. 

Therefore, reaction of iminium chlorides, or their complexes with phosphorus oxychloride, thionyl chloride, carbonyl chloride, etc., with suitable substrates, such as aromatic hydrocarbons, activated methylene compounds and nucleophilic olefins, occurs quite readily. The overall reaction generally results in the formylation of the corresponding substrate. 

These two new alkaloids can be regarded as ammonia added to the hydrocarbon, (methylene) or (etherin) [C=6]. They may also be regarded as methylic... 

The presence of excessive amounts of water in the form of a separate water phase will in many cases increase solvent-induced corrosion of metals. The presence of low molecular weight alcohols added to 1,1,1-Tri can cause increased metal corrosion [2-4]. The presence of aromatic hydrocarbons (e.g., toluene or xylene) in methylene chloride formulations in contact with aluminum can cause catastrophic release of gaseous hydrogen chloride. The trace amounts of aluminum chloride produced by the normally very slow aluminum-solvent reaction acts as a catalyst for the Friedel-Crafts reaction between the aromatic hydrocarbon and methylene chloride. The resultant reaction produces hydrogen chloride which reacts with aluminum to give more aluminum chloride and resulting in a runaway autocatalytic reaction. The addition of an acid... 

Hydrocarbons, aromatic Hydrocarbons, methyl Hydrocarbons, aliphatic Hydrocarbons, aliphatic Hydrocarbons, methylene... 

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