Acetonitrile physical properties

Physical Properties. Ammonium thiocyanate [1762-95-4] NH SCN, is a hygroscopic crystalline soHd which deHquesces at high humidities (375,376). It melts at 149°C with partial isomerization to thiourea. It is soluble in water to the extent of 65 wt % at 25°C and 77 wt % at 60°C. It is also soluble to 35 wt % in methanol and 20 wt % in ethanol at 25°C. It is highly soluble in Hquid ammonia and Hquid sulfur dioxide, and moderately soluble in acetonitrile. 

We had no good way to predict if they would be liquid, but we were lucky that many were. The class of cations that were the most attractive candidates was that of the dialkylimidazolium salts, and our particular favorite was l-ethyl-3-methylimid-azolium [EMIM]. [EMIMJCl mixed with AICI3 made ionic liquids with melting temperatures below room temperature over a wide range of compositions [8]. We determined chemical and physical properties once again, and demonstrated some new battery concepts based on this well behaved new electrolyte. We and others also tried some organic reactions, such as Eriedel-Crafts chemistry, and found the ionic liquids to be excellent both as solvents and as catalysts [9]. It appeared to act like acetonitrile, except that is was totally ionic and nonvolatile. 

When polypyrrole was electrogenerated from dry acetonitrile electrolytes, a black polymer grew and adhered to the electrode. After a few seconds of electropolymerization, a black cloud was observed around the electrode. The film obtained had poor electrochemical and physical properties. Increasing the water content to 2% (w/w) gives, at 800 mV, films with improved properties. The black cloud around the electrode disappears. 

By-products of this reaction are acetonitrile, CH3-C=N, and hydrogen cyanide. This is now a major source of these two materials. Interestingly, the C2 by-product acetonitrile has a bp of 81.6 °C, whereas acrylonitrile with three carbons has a lower bp of 77.3 °C, quite an unusual reversal of this physical property s dependence on molecular weight. The TWA of acrylonitrile is 2 ppm and it is on the list of Reasonably Anticipated to Be Human Carcinogens. ... 

The compound Os3(CO)j j(C5H5N) is very soluble in acetonitrile, dichl-oromethane, acetone, and methanol, and its solutions are stable to air. It is sparingly soluble in hydrocarbons. Its purity can be checked by IR spectroscopy (dichloromethane solution) v(CO)cm 1 2106(w), 2052(s), 2035(vs), 2008 (s), 1976 (m). Other physical properties have been reported.2 The vacuum pyrolysis of this compound provides a high-yield route to the carbido-dianion [Os10C(CO)24]2-.5... 

Acetonitrile has been selected as the solvent in this study since it is a possible candidate for a nonaqueous electrolyte battery (5). From this viewpoint, acetonitrile has several attractive physical properties, as shown in Table I. It has a useful liquid state range and a reasonably low vapor pressure and viscosity at ambient temperature. In addition, many common electrolytes are soluble in acetonitrile. Acetonitrile is a good model solvent for solvation studies, as the molecule is a linear aprotic dipole. 

Acetonitrile Chloro-difluoro- ElOa. 25 (Physical Properties). 674 (Educt)... 

Organic constituents that may be found in ppb levels in WP/F smoke include methane, ethylene, carbonyl sulfide, acetylene, 1,4-dicyanobenzene, 1,3-dicyanobenzene, 1,2-dicyanobenzene, acetonitrile, and acrylonitrile (Tolle et al. 1988). Since white phosphorus contains boron, silicon, calcium, aluminum, iron, and arsenic in excess of 10 ppm as impurities (Berkowitz et al. 1981), WP/F smoke also contains these elements and possibly their oxidation products. The physical properties of a few major compounds that may be important for determining the fate of WP/F smoke in the environment are given in Table 3-3. 

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-... 

Table 11.2 presents fundamental physical properties for the key components implied in separations. The difference in the boiling points favors the separation, except of acrylonitrile and acetonitrile. The differences in the freezing point are also sensitive, but they did not justify the investment in a separation by crystallization. It remains that distillation-based separation methods should be tried in the first place. However, the formation of azeotropes of components with water will present difficulties. 

Ligands 179 and 180 were synthesized by the nucleophilic substitution of the sodium glycolate of TV-methyldiethanol amine on either 2,6-dichloropyridine or 2,6-6 (chloromethyl)pyridine. However, 183 and 184 were synthesized by the qua-temization of 181 or 182 with l,2-6is(P-ethoxy)ethane in acetonitrile. In both instances the resulting diquatemary ammonium salts were demethylated by L-Selec-tride in refluxing tetrahydrofuran to afford the desired pyridino coronand. Com-piexation studies have not been performed on any of these coronands and the physical properties of these compounds do not indicate any unusual characteristics m). 

Very recently, the separation of polar analytes has also been performed by using pure water under subcritical conditions. Subcritical water has several unique characteristics. For example, the dielectric constant, surface tension, and viscosity of water are dramatically decreased by raising the water temperature while a moderate pressure is applied to keep water in the liquid state. At 200 -250°C, the values of these physical properties are similar to those of pure methanol or acetonitrile at ambient conditions. Therefore, subcritical water may be a potential mobile phase for polar analytes. SFC mobile phases other than CO2 are reviewed separately in this encyclopedia. 

Among the industrial alternatives proposed to produce isoprene, extractive distillation appears to be the best As for butadiene, the main solvents employed are acetonitrile (ARCO, Exxon, Japan Synthetic Rubber, Nippon Petrochemical, Shell, N-methylpyrroli-done BASF), and dimethytformamide [Nippon Zeony Their physical properties were given partly in Table 3.4. By modifying the relative volatilities of the components, as... 

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