Ammonia reaction with gaseous

After apphcation to the fabric, the compounds are polymerized by reaction with gaseous ammonia (11,12), then oxidized to phosphine oxides by reaction with hydrogen peroxide. The stmcture of the polymer is shown (13). 

Solid lactones or cyclic carbonates form linear hydroxy amides upon reaction with gaseous ammonia, methylamine, or ethylamine. For example, the compounds 277a-c and (ketonized) 279a-c are quantitatively formed at 0 °C and room temperature, respectively, without melting [12] (Scheme 39). 

On balance then the evidence favours the hypothesis that the selectivity in ammonia oxidation is determined by competition between NH 3 and O2 molecules for active step sites and not by the relative rates of NO desorption and reaction with ammonia. Conditions can be found favouring complete coverage of active sites by N atoms (<200 °C, desorption rate limited), or by NH3 molecules (200—500 °C, Eley-Rideal reaction with gaseous oxygen) or by O atoms (500— 1000 °C, Eley-Rideal reaction with gaseous ammonia). Above 1000 °C, simple NH3 decomposition supervenes, perhaps with oxidation of the hydrogen thus liberated. 

The prototype of this class, OP(NH2)3, is formed in the reaction of OPCI3 with liquid ammonia " or with gaseous NH3 in trichloromethane solution at low temperature. " Substituted phosphoric acid triamides 0=P(NR2)3 are prepared in the reaction of phosphorus oxotrichloride with secondary amines, under heating or in the presence of acid scavengers under milder conditions the mono- and diamido chlorides can be easily obtained (equations). " Hexamethylphosphoric acid triamide, OP(NMe2)3, an excellent aprotic organic solvent prepared from OPCI3 and dimethylamine, deserves to be mentioned here. ... 

According to this scheme, ammonia is first adsorbed on site M (step a) then adsorbed ammonia is activated by a nearby site S (step b), and eventually the adsorbed activated ammonia undergoes a reaction with gaseous NO (step c). The resulting kinetic expression, derived by assuming that step a) is fast, is the following ... 

Ammonia—Gas-Cured Flame Retardants. The first flame-retardant process based on curing with ammonia gas, ie, THPC—amide—NH, consisted of padding cotton with a solution containing THPC, TMM, and urea. The fabric was dried and then cured with either gaseous ammonia or ammonium hydroxide (96). There was Httle or no reaction with cellulose. A very stable polymer was deposited in situ in the cellulose matrix. Because the fire-retardant finish did not actually react with the cellulose matrix, there was generally Httle loss in fabric strength. However, the finish was very effective and quite durable to laundering. 

The gaseous ammonia is passed through electrostatic precipitators for particulate removal and mixed with the cooled gas stream. The combined stream flows to the ammonia absorber where the ammonia is recovered by reaction with a dilute solution of sulfuric acid to form ammonium sulfate. Ammonium sulfate precipitates as small crystals after the solution becomes saturated and is withdrawn as a slurry. The slurry is further processed in centrifuge faciHties for recovery. Crystal size can be increased by employing one of two processes (99), either low differential controUed crystallization or mechanical size enlargement by continuous compacting and granulation. 

Phosphoms trichloride and pentachloride form sodium chloride and sodium phosphide, respectively, in the presence of sodium. Phosphoms oxychloride, POCl, when heated with sodium, explodes. Carbon disulfide reacts violendy, forming sodium sulfide. Sodium amide (sodamide), NaNH2, is formed by the reaction of ammonia gas with Hquid sodium. SoHd sodium reacts only superficially with Hquid sulfur dioxide but molten sodium and gaseous... 

The production of nitrogen fertilizers is a major activity of the chemical industry. Every year, the top 15 chemicals in industrial production in the United States include several nitrogen-containing compounds whose major use is in fertilizers. Molecular nitrogen serves as the primary source of nitrogen for chemical production. Gaseous ammonia (NH3), which is synthesized from N2 and H2, can be injected directly into the ground, where it dissolves in moisture in the soil and serves as a fertilizer. Ammonia is more widely used in reactions with acids to produce other fertilizers Ammonia and nitric acid produce ammonium nitrate (NIL) NO3), while ammonia and sulfuric acid produce ammonium sulfate. These chemicals and urea,... 

Other Gas Reactions. Several other reactive gases or vapours were examined but found to be unsatisfactory. No ester formation ( 1745 cm"1) was found when oxidatized films were exposed to acetic acid or formic acid vapour. Alcohol/carboxylic acid reactions in the solid state have often been suggested as the source of ester products, but not substantiated (4,5). Gaseous ammonia reacted with carboxylic acid groups to give absorptions at 1550 cm"1 [-C(=0)-0 ] and 1300 cm"1 (NHi +). However, these absorptions were very broad and the method inferior to acid measurement by SF. Although N20 did not react with oxidized polyolefins, the reaction of N02 with oxi-... 

Even though the CMR and MBR operate under conditions in which pressure is developed, gaseous reactants or media often can be handled in these systems without problems arising through over-pressure. Mannich reactions with dimethylamine, Baylis-Hillman reactions with formaldehyde, aminoreductone formation with ammonia, all proceeded without difficulty, as did Willgerodt reactions in which gases are formed during the process. 

The reaction of S2C12 with gaseous ammonia in DMF at ca. -10 °C, followed by hydrolysis with cold dilute hydrochloric acid, is a standard preparation of these cyclic sulfur imides.199 The reaction of sodium azide with elemental sulfur in (Me2N)3PO is an excellent source of S7NH. The tetraimide 69 is prepared by reduction of S4N4 with methanolic SnCl2.2H20. 

FIGURE 8.2 Synthesis of isoglutamine by reaction of the mixed anhydride of protected glutamic acid with gaseous ammonia followed by deprotection by hydrogenolysis.11 a = EtOCOCl/Bu3N in dioxane b = anhydrous NH3 c = H2/Pd(CaC03). 

Curtin and Paul have carried out a series of elegant studies on the reactivity of single crystals of acids and anhydrides with gaseous ammonia (92,93). They demonstrated that these reactions are highly anisotropic, with the ammonia... 

Cyclohexylurea has been prepared by the reaction of cyclo-hexyl isocyanate with gaseous ammonia or ammonium hydroxide, by thermal decomposition of cyclohexyl allophanamide, by treating cyclohexylamine hydrochloride with an aqueous solution of potassium cyanate," by heating nitrosomethylurea with cyclohexylamine, and by heating an ethanolic solution of cyclohexylamine and 3,5-dimethyl-l-carbamylpyrazole. 2,6-DimethyIphenyIthiourea has been synthesized by allowing 2,6-dimethylaniline hydrochloride to react with ammonium thiocyanate. ... 

Heterogeneous fluid-fluid reactions are made to take place for one of three reasons. First, the product of reaction may be a desired material. Such reactions are numerous and can be found in practically all areas of the chemical industry where organic syntheses are employed. An example of liquid-liquid reactions is the nitration of organics with a mixture of nitric and sulfuric acids to form materials such as nitroglycerin. The chlorination of liquid benzene and other hydrocarbons with gaseous chlorine is an example of gas-liquid reactions. In the inorganic field we have the manufacture of sodium amide, a solid, from gaseous ammonia and liquid sodium ... 

In the following we shall focus on heterogeneous acid-base reactions. One of the best known case studies is the reaction of crystalline benzoic acid with ammonia to form 1 1 ammonium salts [19, 20]. Crystalline p-chlorobenzoic anhydride reacts with gaseous ammonia to give the corresponding amide and ammonium salt [22] a similar reaction has been investigated in the case of optically active cyclopropanecarboxylic acid crystals [23]. 

A series of solid-state reactions has been explored by Kaupp et al., in which gaseous amines were reacted with aldehydes to give imines. Analogous reactions with solid anhydrides, imides, lactones or carbonates, and isothiocyanates were used to give, respectively, diamides or amidic carboxylic salts or imides, diamides, carbamic acids, and thioureas [24]. In general the yields were found to be quantitative. Ammonia and other gaseous amines, in particular methyl-amine, have also been shown to aminolyse thermoplastic polycarbonates [25]. 

The gas-solid neutralizations found more interest than the solid-solid variant. The quantitative reactions of gaseous ammonia with solid benzoic and related acids were interpreted by a concept of gas permeability of the crystal in order to explain anisotropic reaction fronts in single crystals [24]. Also, the ammonium salts of the aromatic or aliphatic mono- and dicarboxylic acids 16-21 (Scheme 3) formed the corresponding salts with 100% yield. The need for molecular migrations immediately upon reaction was not considered at that... 

Very weak acids such as 2-mercaptobenzothiazole (32) [27], saccharine (34), 5,5-diphenylthiohydantoin (36) [31], or 5-yhdene-thiohydantoins (38) [32] form salts with methylamine gas (Scheme 4). Such quantitatively formed salts (33,35,37,39) cannot be obtained in solution. This new possibility of reaction was studied and interpreted with AFM [1,27]. Even C-H acids such as barbituric acids 40, which crystallize as the triketo tautomers, form the ammonium barbiturates 41 with gaseous bases such as ammonia or dimethylamine with great ease [32]. 

Solid cyclic carboxylic anhydrides react with gaseous ammonia to give amide ammonium salts with quantitative yield. This has been observed with the labile Diels-Alder adduct 259 [25] (Scheme 38). Aliphatic amine vapors are equally able to open anhydride rings to form the amide salts from where the free amide acids can be obtained in 100% yield. The reaction of 261 with ethylamine to give 262 is an example of a large-scale preparative application [11-12]. Conversely, solid pyromellitic bis-anhydride (263) and methylamine vapor react exother-mally (rise to 95 °C) and quantitatively to yield the tetraamide 264. Interest-... 

Trimethylamine replaces PH3 quantitatively in BH3 PH3 to give BH3 N(CH3)3. Liquid or gaseous ammonia also replaces phosphine in the compound BH3 PH3 to the extent of 52-58% or up to 75%, respectively. The hydrogen atoms bonded to boron are partially, or completely, replaced by chlorine on treatment with hydrogen chloride, depending on the reaction conditions. The first stage of the reaction with hydrogen chloride is the formation of the colourless, viscous liquid BHjCl PH3 (see below). 

The product decomposes on sublimation forming mercury(ll) chloride, ammonia, and nitrogen. However, in the presence of ammonium chloride, the same reaction with ammonia with HgCb in aqueous solution yields fusible white precipitate, (NH3)2HgCl2. Similar product also is obtained by reaction of gaseous ammonia with solid mercury(II) chloride. However, the solid mer-cury(II) chloride is more stable than the above infusible product and can be melted without decomposition. 

Nickel is stable in caustic alkahes. At moderate temperatures, it decomposes gaseous ammonia into hydrogen and nitrogen. Nickel combines with sulfur, phosphorus, carbon, arsenic, antimony, and aluminum at elevated temperatures. Fusion of nickel powder with molten sulfur yields nickel sulfide, NiS. Reaction with aluminum can be explosive at 1,300°C, forming nickel-aluminum intermetallic products of varying compositions. 

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