Dimethyl carbonate, physical properties

Uses. The chemical inertness, thermal stability, low toxicity, and nonflammability of PFCs coupled with their unusual physical properties suggest many useflil applications. However, the high cost of raw materials and manufacture has limited commercial production to a few, small-volume products. Carbon tetrafluoride and hexafluoroethane are used for plasma, ion-beam, or sputter etching of semiconductor devices (17) (see loN implantation). Hexafluoroethane and octafluoropropane have some applications as dielectric gases, and perfluorocyclobutane is used in minor amounts as a dielectric fluid. Perfluoro-1,3-dimethyl cyclohexane is used as an inert, immersion coolant for electronic equipment, and perfluoro-2-methyldecatin is used for... 

The physical properties of finish removers vary considerably due to the diverse uses and requirements of the removers. Finish removers can be grouped by the principal ingredient of the formula, method of appHcation, method of removal, chemical base, viscosity, or hazardous classification. Except for method of apphcation, a paint remover formulation usually has one aspect of each group, by which it can be used for one or more appHcations. A Hst of the most common organic solvents used in finish removers has been compiled (3). Many are mentioned throughout this article others include ethyl lactate [97-64-3] propylene carbonate [108-32-7] furfural alcohol [98-01-1/, dimethyl formamide [68-12-2] tetrahydrofuran [109-99-9] methyl amyl ketone [110-43-0] dipropylene glycol methyl ether [34590-94-8] and Exxate 600, a trade name of Exxon Chemicals. 

Dimethylarsinic acid (DMA), 3 274 present in water and food, 3 276t Dimethylbenzyl carbinol, aroma chemical derived from toluene, 3 234 N, AT-Dimethylbenzyl vinyl amine (DMBVA), 20 487 Dimethylbismuthine, 4 18, 26 Dimethylbromostibine, 3 68 Dimethylcadmium, 4 516-517 physical properties of, 4 517t Dimethyl carbonate, 6 313-314... 

Ethers are organic compounds structurally related to alcohols. The oxygen atom in an ether group, however, is bonded not to a carbon and a hydrogen but rather to two carbons. As we see in Figure 12.14, ethanol and dimethyl ether have the same chemical formula, C2H(50, but their physical properties are vastly different. Whereas ethanol is a liquid at room temperature (boiling point 78°C) and mixes quite well with water, dimethyl ether is a gas at room temperature (boiling point —25°C) and is much less soluble in water. 

The oxygen in an alcohol, such as ethanol, is bonded to one carbon atom and one hydrogen atom. The oxygen in an ether, such as dimethyl ether, is bonded to two carbon atoms. Because of this difference, alcohols and ethers of similar molecular mass have vastly different physical properties. 

Although a number of solvents have been used by different workers, only a few enjoy continued favor. In Table 7.11 the physical properties of more than 50 solvents are listed (not all of them are aptotic). In the following paragraphs some of the properties and purification methods for four solvents are discussed acetonitrile, propylene carbonate (PC), dimethylformamide (DMF), and dimethyl sulfoxide (Me2SO). These are the most widely used solvents and prob-... 

PHYSICAL PROPERTIES Appearance and odor vary depending upon the specify organic arsenic compound. Physical properties of specific compounds are provided for illustrative purposes, (arsenic diethyl) liquid or oil BP (185-190 C, 365-374°F) DN (about 1.0 g/mL) SG (about 1.0). (arsenic dimethyl) colorless to yellow oily liquid MP (-6°C, 21.2°F) BP (186°C, 366.8°F) DN (1.15 g/mL) SG (1.15). (arsenoacetic acid) minute yellow needles does not melt below 260 C (500°F) decomposition begins at about 205°C (401 F) readily soluble in pyridine, dilute sodium carbon-ate and dilute sodium hydroxide solutions insoluble in water and common organic solvents. 

PHYSICAL PROPERTIES clear, colorless liquid heavy, mobile liquid chloroform-like odor very slightly soluble in water miscible with methanol, ethanol, carbon tetrachloride, benzene, ether, petroleum ether, carbon disulfide, chloroform, dimethyl formamide, and... 

The compound dimethyl ether is a gas with a boiling point of — 24 °C. It is clearly a different substance from ethyl alcohol, differing not only in its physical properties but also in its chemical properties. It does not react at all with sodium metal. Like ethyl alcohol, it reacts with hydriodic acid, but it yields a compound of formula CH3I. Analysisof dimethyl ether show that it contains carbon, hydrogen, and oxygen in the same proportion as ethyl aleohol, 2C. 6H 10. It has the same molecular weight as ethyl alcohol, 46. We conclude that it has.the same molecular formula C2H6O. 

E. coli and S. aureus Some quinuclidinium compounds were quite active in vitro with the most active XVIII having MIC values of 0.4 ug/ml for S. aureus and B. subtilis. A group of 68 N,N-dimethyl-N-alkyl-2-aryloxyethyl ammonium bromides were prepared and screened vs 8 common infectious organisms, and the best had alkyl groups of from 8-12 carbon atoms, with MIC values as low as 0.5 yg/ml. Bis-quaternary salts of ethylene and hexamethylene diamine of type XIX were active in vitro . The most active had R=CioH2i and the chloride had greater activity than the corresponding iodide. Another paper dealt with the structure-activity relationships of compounds of type XIX . Various physical properties such as pH, wettability, viscosity, surface tension, etc. were related to activity. 

Nanbu, N. Takehara, M. Watanabe, S. Ue, M. Sasaki, Y., Polar effect of successive fluori-nation of dimethyl carbonate on physical properties. Bull. Chem. Soc. Jpn. 2007, 80, 1302-1306. 

High pressure fluid phase equilibrium data of poly(dodecyl acrylate) in carbon dioxide and dimethyl ether Data extract from Landolt-Bornstein VIII/6D3 Polymers, Polymer Solutions, Physical Properties and their Relations I (Thermodynamic Properties Equilibria of Ternary Polymer Solutions) ... 

Aprotic electrolytes based upon methyl formate, propylene carbonate and dimethyl formamide as solvents and lithium chloride plus aluminum chloride, lithium hexafluoroarsenate and lithium perchlorate as solutes are discussed. The effect of additives, other aprotic solvents, other salts and trace amounts of water on species in solution and other physical properties are described. 

Reaction of 1 with benzaldehyde and zinc chloride gave a diastereomeric mixture (6) of R- and 5-2,3-O-benzylidene derivatives (4a and 4b). The former (4a) would be identical to the acetal described by Zinner et al. (3) as 2,4-O-benzylidene-D-ribono-1,5-lactone. This structure was further established as 4a, by chemical and physical studies of the product obtained on reaction of 1 with benzaldehyde dimethyl acetal (7). The 2,3-O-benzylidene derivative, obtained by Garegg et al. (8) on reaction of 1 with a,a-dichlorotoluene in pyridine, has the same properties as compound 4a, which would indicate the -configuration for the acetal carbon. 

In addition to the equipment properties and selected operating conditions, the process performance depends to a large extent on the state of the active solvent component(s). Commonly nsed solvents include physical solvents like methanol (Rectisol) and the dimethyl ethers of polyethylene glycol (Selexol), chemical solvents like aqneous solutions of carbonates such as K2CO3 and Na2C03, of amino acid salts such as mixtures of potassium hydroxide and alanine or tanrine, and especially of alkanolamines such as mono-ethanolamine (MEA), di-ethanolamine (DEA), (activate) methyl-di-ethanolamine (MDEA), di-isopropanolamine (DIPA), di-glycolamine (DGA), 2-amino-2-methyl-l-propanol (AMP), and piperazine (PZ) (1). 

Many nonaqueous solvents have been proposed as suitable media for the determination of substances with weakly acidic properties or of their mixtures, but only some of them have found widespread use, because of their suitable characteristics and practical advantages. Thus, liquid ammonia and ethylene diamine (1,2-diaminoethane) show unsuitable physical characteristics and high basicity and absorb atmospheric carbon dioxide. Dimethyl sulfoxide and pyridine are unpleasant to use and dangerous in everyday work, although a series of chemical indicators have been established for use in these two solvents. On the other hand, N,N-dimethylform-amide (DMF) is a very popular solvent for the titration of acids and mixtures of acids, and isopropyl and -butyl alcohols show a large resolution of acid strength and allow to successfully solve acid mixtures. 

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