Hquid ammonia solutions

Heat a mixture of 15 g. of p-nitroacetanilide and 75 ml. of 70 per cent, sulphuric acid (1) under a reflux water condenser for 20-30 minutes or until a test sample remains clear upon dilution with 2-3 times its volume of water. The p-nitroaniline is now present in the hquid as the sulphate. Pour the clear hot solution into 500 ml. of cold water and precipitate the p-nitroanihne by adding excess of 10 per cent, sodium hydroxide solution or of concentrated ammonia solution. When cold (cool the mixture in ice water, if necessary), filter the yellow crystalline precipitate at the pump, wash it well with water, and drain thoroughly. Recrystallise it from a mixture of equal volumes of rectified (or methylated) spirit and water or from hot water. Filter, wash and dry. The yield of p-nitroanihne, m.p, 148°, is 11 g. 

Articles fabricated from FEP resins can be made bondable by surface treatment with a solution of sodium in Hquid ammonia, or naphthalenyl sodium in tetrahydrofuran (64) to faciUtate subsequent wetting. Exposing the surface to corona discharge (65) or amines at elevated temperatures in an oxidizing atmosphere (66) also makes the resins bondable. Some of the more recent work is described in References 67—69. 

Adberabibty of the film may be enhanced by its treatment with flame, electric discharge, boron trifluoride gas, activated gas plasma, dichromate sulfuric acid, and a solution of alkab metal ia Hquid ammonia (84—87). A coating of polyurethane, an alkyl polymethacrylate, or a chlotinated adhesive can be apphed to PVF surfaces to enhance adhesion (80,88,89). 

Iron(III) bromide [10031-26-2], FeBr, is obtained by reaction of iron or inon(II) bromide with bromine at 170—200°C. The material is purified by sublimation ia a bromine atmosphere. The stmcture of inoa(III) bromide is analogous to that of inon(III) chloride. FeBr is less stable thermally than FeCl, as would be expected from the observation that Br is a stronger reductant than CF. Dissociation to inon(II) bromide and bromine is complete at ca 200°C. The hygroscopic, dark red, rhombic crystals of inon(III) bromide are readily soluble ia water, alcohol, ether, and acetic acid and are slightly soluble ia Hquid ammonia. Several hydrated species and a large number of adducts are known. Solutions of inon(III) bromide decompose to inon(II) bromide and bromine on boiling. Iron(III) bromide is used as a catalyst for the bromination of aromatic compounds. 

Like the other alkah metals (45), lithium has appreciable solubiUty in Hquid ammonia. A saturated solution at —33.2° C contains 15.7 mol lithium in 1000 g of ammonia, and at 19°C has a density of 0.477, lower than that of any other known Hquid. Lithium reacts readily in Hquid ammonia to form... 

Lithium acetyhde also can be prepared directly in hquid ammonia from lithium metal or lithium amide and acetylene (134). In this form, the compound has been used in the preparation of -carotene and vitamin A (135), ethchlorvynol (136), and (7j--3-hexen-l-ol (leaf alcohol) (137). More recent synthetic processes involve preparing the lithium acetyhde in situ. Thus lithium diisopropylamide, prepared from //-butyUithium and the amine in THF at 0°C, is added to an acetylene-saturated solution of a ketosteroid to directly produce an ethynylated steroid (138). 

Ammonia is readily absorbed ia water to make ammonia liquor. Figure 2 summarizes the vapor—Hquid equiUbria of aqueous ammonia solutions and Figure 3 shows the solution vapor pressures. Additional thermodynamic properties may be found ia the Hterature (1,2). Considerable heat is evolved duriag the solution of ammonia ia water approximately 2180 kJ (520 kcal) of heat is evolved upon the dissolution of 1 kg of ammonia gas. 

Fig. 3. Vapor pressure of aqueous ammonia solution (1). Numbers represent the weight percent of ammonia in the Hquid. To convert kPa to psi, multiply...

Bina Selenides. Most biaary selenides are formed by beating selenium ia the presence of the element, reduction of selenites or selenates with carbon or hydrogen, and double decomposition of heavy-metal salts ia aqueous solution or suspension with a soluble selenide salt, eg, Na2Se or (NH 2S [66455-76-3]. Atmospheric oxygen oxidizes the selenides more rapidly than the corresponding sulfides and more slowly than the teUurides. Selenides of the alkah, alkaline-earth metals, and lanthanum elements are water soluble and readily hydrolyzed. Heavy-metal selenides are iasoluble ia water. Polyselenides form when selenium reacts with alkah metals dissolved ia hquid ammonia. Metal (M) hydrogen selenides of the M HSe type are known. Some heavy-metal selenides show important and useful electric, photoelectric, photo-optical, and semiconductor properties. Ferroselenium and nickel selenide are made by sintering a mixture of selenium and metal powder. 

Sodium forms unstable solutions in Hquid ammonia, where a slow reaction takes place to form sodamide and hydrogen, as foUows ... 

Ammonium tungstate [11140-77-5] (NH 2 0cannot be obtained from an aqueous solution because it decomposes when such a solution is concentrated. It is prepared by the addition of hydrated tungstic acid to Hquid ammonia. 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

Bismuth ttiiodide may be prepared by beating stoichiometric quantities of the elements in a sealed tube. It undergoes considerable decomposition at 500°C and is almost completely decomposed at 700°C. However, it may be sublimed without decomposition at 3.3 kPa (25 mm Hg). Bismuth ttiiodide is essentially insoluble in cold water and is decomposed by hot water. It is soluble in Hquid ammonia forming a red triammine complex, absolute alcohol (3.5 g/100 g), benzene, toluene, and xylene. It dissolves in hydroiodic acid solutions from which hydrogen tetraiodobismuthate(Ill) [66214-37-7] HBil 4H2O, may be crystallized, and it dissolves in potassium iodide solutions to yield the red compound, potassium tetraiodobismuthate(Ill) [39775-75-2] KBil. Compounds of the type tripotassium bismuth hexaiodide [66214-36-6] K Bil, are also known. 

Colorless oily hquid fumes in air etches glass density 2.666 g/ml at 0°C hods at 60.4°C vapor pressure 100 torr at 13.2°C sohdilies at -8.5°C decomposes in water soluble in alcohol, ether, benzene and ammonia solution. 

In very finely divided form, lead is pyrophoric. When heated in oxygen or air, the metal forms lead monoxide, PbO, which is oxidized further in the presence of excess oxygen or air to lead tetroxide, Pb304. The finely divided metal dissolves in a solution of sodium in hquid ammonia, forming a green solution of Na4Pbg. 

White or slight yellow prismatic granules deliquesc density 1.915 g/cm melts at 440°C decomposition starts at 350°C very soluble in water, 281 g/lOOmL at 0°C much more soluble in boiling water, 413 g/lOOmL at 100°C aqueous solution is alkaline slightly soluble in cold alcohol but moderately solublel in hot alcohol very soluble in hquid ammonia decomposes in acids, liberating brown NO2 fumes. 

This reaction is catalyzed by iron, cobalt, and nickel. Rate of reaction depends on temperature and concentration of sodium in hquid ammonia. At a temperature of -41.6°C and high concentration, the solution separates into two hquid phases that consist of a deep blue dilute solution at the bottom that is low in sodium, and a hghter solution of metalhc bronze color on the top with a high sodium. Molten sodium reacts with ammonia gas at 300 to 400°C to form sodium amide. 

Triple bonds can also be selectively reduced to double bonds with diisobutyla-luminum hydride (Dibal-H), ° with activated zinc (see 12-38), with hydrogen and Bi2B-borohydride exchange resin, or (internal triple bonds only) with alkali metals (Na, Li) in hquid ammonia or a low-molecular-weight amine. Terminal alkynes are not reduced by the Na NH3 procedure because they are converted to acetylide ions under these conditions. However, terminal triple bonds can be reduced to double bonds by the addition to the Na—NH3 solution of (NH4)2S04, which liberates the free ethynyl group. The reaction of a terminal alkyne with... 

Bases behave similarly. Although sodium hydroxide is a strong base in water, it is less ionised in anhydrous alcohol than sodium ethoxide, CgHgONa, the anion of which, CgHgO", also appears in solutions of amines in ethyl alcohol. In hquid ammonia, the anion present is NH ". These liquids exemplify solvents in which the anion is not hydroxide. 

Solutions of sodium acetylide (HC CNa) may be prepared by adding sodium amide (NaNH2> to acetylene in hquid ammonia as the solvent. Terminal alkynes react similarly to give species of the type RC CNa. 

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