Lithium bromide ammonium

The first reported synthesis of acrylonitrile [107-13-1] and polyacrylonitrile (PAN) [25014-41-9] was in the 1890s (1). The polymer received little attention for a number of years, until shortly before World War II, because there were no known solvents and the polymer decomposes before reaching its melting point. The first breakthrough in developing solvents for PAN occurred at I. G. Farben in Germany, where fibers made from the polymer were dissolved in aqueous solutions of quaternary ammonium compounds, such as benzylpyridinium chloride, or of metal salts, such as lithium bromide, ammonium thiocyanate, and zinc... 

Lithium acetate ammonium sulfate azide benzoate borate (meta-) bromate bromide carbonate chlorate chloride... 

According to F. C. Franklin and C. A. Kraus,40 liquid ammonia readily dissolves sodium and potassium iodides. The partial press, of ammonia in soln. of potassium iodide at 25°, as measured by R. Abegg and H. Riesenfeld, is raised from 13 45 mm. of water to 13 28, and 14 88 mm. for 0 5W-, N-, and l 5Ar-soln. respectively. H. M. Dawson and J. McCrae have shown that the distribution of ammonia between water and chloroform is generally lowered by the addition of various salts of the alkali metals and ammonium which they tried—halides, nitrates, chlorates, oxalates, sulphates, carbonates, hydroxides this means that the solvent power of aq. soln. of the alkali salts is in general less than that of pure water—lithium chloride, ammonium bromide, and sodium iodide act in the opposite way. The other halide salts of lithium were not tried. The change produced in the partition coeff. by the halides, at 20°, is as follows ... 

Overall polymerization rates which are equated with the rate of propagation were first order in monomer and very fast. At -78 °C the rate constants fell between 1.0 and 3.4 x 1051 mol-1 s 1. Activation energies were very small, 2.2 and 5.5 kJ mol-1 for ethyl (EGA) and butyl (BCA) cyanoacrylates, respectively. Of a range of ammonium, phosphonium, and alkali metal salts only lithium bromide significantly reduced the rate of polymerization. Ogawa and Romero16 found the rate of acrylonitrile polymerization increased by the presence of an ammonium salt but reduced by lithium chloride. There may be a specific interaction between cyano substituted carbanions and the lithium cation. 

It has been noted elsewhere that the order of addition of reagents is the most important single variable to influence product distribution. A procedure which is convenient and normally reliable is based on the addition of small pieces of metal to a mixture of substrate, ammonia, solvent and (if appropriate) alcohol at less than -70 °C until the blue colour persists for a reasonable period (approximately 10 min). For less reactive substrates, lithium should be used and the addition of the alcohol delayed so that a higher concentration of metal is maintained during the reduction process. Quenching is best effected by 1,3-penta-diene (or similar substance), followed either by ammonium chloride or another electrophile. In reactions where in situ alkylations are performed these are best carried out on lithium derivatives, so in cases where other metals have been used for reduction carefully dried lithium bromide is added before the electrophile. 

Dimerizations of aryldiazomethanes to 1,2-diarylethylenes were reported to be catalyzed by cerium(IV) ammonium nitrate (4J), lithium bromide (42), copper(II) salts (43), and rhodium(II) acetate (44) and to be induced by photolysis (45). Catalysis of copper ion-exchanged zeolite (CuNaY) was compared with reactions of copper salts supported on AI2O3 and a homogeneous catalyst, Cu(C104)2, for the dimerization [Eq. (11)] of aryldiazomethane (Table XIII) (-/6). 

The same material is also obtained when bromomethyltrimethyl-ammonium bromide is treated with phenyllithium in ether. Although the lithium bromide complex of the ylid is insoluble in ether, the solid can be dissolved in tetrahydrofuran (THF) in concentrations up to 0.9 M 39>. 

Although cyclic sulfites 549 of tartrate esters are less reactive than the corresponding cyclic sulfates 540, they do react with such good nucleophiles as lithium bromide, lithium chloride, sodium azide, ammonium thiocyanate, or sodium acetate in polar aprotic solvents (DME, THE or DMF) to provide ) -substituted-D-malates 550. Quantitative yields of 549 can be... 

Solids dry chemicals such as sodium chloride, lithium bromide, sodium bicarbonate, potassium bicarbonate, ammonium phosphate, potassium chloride, potassium bicarbonate, and graphite. 

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