Barium acetate bromide

By suitable modification, the procedure used to prepare barium chloride may be adopted to prepare other barium salts such as the acetate, bromide, and nitrate. The final volume of the solution should be adjusted so as to give a nearly saturated solution at 25°. The solubility of these salts will be found on page 365. 

Ammonium bifluoride Barium acetate Benzyltriethyl ammonium bromide Cobalt perchlorate (ous) Indole Lead nitrate Nickel chloride (ous) Phenylhydrazine Tributyl phosphate Zinc cyanide... 

Hydrogenation using Raney nickel is carried out under mild conditions and gives cis alkenes from internal alkynes in yields ranging from 50 to 100% [356, 357, 358, 359, 360]. Half hydrogenation of alkynes was also achieved over nickel prepared by reduction of nickel acetate with sodium borohydride (P-2 nickel, nickel boride) [349,361,362] or by reduction with sodium hydride [49], or by reduction of nickel bromide with potassium-graphite [363]. Other catalysts are palladium on charcoal [364], on barium sulfate [365, 366], on... 

Chemical kinetics deductions are, in some circumstances, possible from a reaction system using a dispersed solid. If the solid is entirely insoluble, for example a supported catalyst, true surface kinetics can be obtained provided (i) it can be shown that the chemical reaction on the surface is much slower than the associated mass transfer, and (ii) the surface area of the solid can be obtained. These conditions applied in the case of the oxidation of an aqueous solution of hydrazine using a dispersion of insoluble barium chromate [16]. Another case is where it can be shown that an increase in the amount of the solid component does not increase the reaction rate. In this case, exemplified by the formation of benzyl acetate from benzyl bromide and solid sodium acetate in toluene solvent, it is likely that the reaction occurs in the solution phase and that the reaction is proceeding at the saturation concentration of the solid reactant in the liquid phase [17]. 

Hydroxylamine-O-sulfonic acid reacts with hydrazine to form a precipitate of triazanium hydrogensulfate (H2NNH2 NH2)+ HS04. Reaction of this solution with an appropriate barium salt in 0.1 M aqueous solution yielded solutions of the nitrate, perchlorate, chlorate, acetate, cyanide, bromide, and hydroxide salts. The stability of the salts decreases in the order hydrogen sulfate > nitrate > perchlorate > chlorate > acetate > azide > cyanide > bromide > hydroxide. The stabihty of the solutions decreases with decreasing H+ concentration, thus stronger acids form more stable salts. 

This, the best known of the glycols, is prepared by the action of dry silver acetate upon ethylene bromide. The ether so obtained is purified by redistiUation, and decomposed by heating for some time with barium hydrate. 

Caprolactone (CL) (Acros, 99%) was dried over calcium hydride at r.t. for 48h and then distilled under reduced pressure. 2-(N,N-dimethylamino)ethyl methaciylate (DMAEMA) (Aldrich, 98%) was deprived of its inhibitor by filtration through a basic alumina column, and depending on samples (see text) dried over calcium hydride at r.t. for 24h and then distilled under reduced pressme. Butane-1,4-diol (Acros, > 99%) was dried over calcium hydride for 48h at r.t. and distilled at 70°C under reduced pressure. Triethylamine (NEts, Fluka, 99%) was dried over barium oxide for 48h at r.t. and distilled under reduced pressure. Copper bromide (CuBr, Fluka, 98%) was purified in acetic acid and recrystallized in ethanol under inert atmosphere until a white powder is obtained. Tin(ll) bis-2-ethyl hexanoate (Sn(Oct)2, Aldrich, 95%), methacrylic anhydride (Aldrich, 94%), N,N-dimethylamino-4-pyridine (DMAP, Acros 99%), 1,1,4,7,10,10-hexamethyltriethylene tetramine (HMTETA, Aldrich, 97%), ethyl-2-bromoisobutyrate (E BBr, Aldrich, 98%), N,N-dicyclohexylcarbodiimide (DCC, Acros, 99%), were used as received. Tetrahydrofuran (THF, Labscan, 99%) was dried over molecular sieves (4A) and distilled over polystyryl lithium (PS LC) complex under reduced pressure just before use. Toluene (Labscan, 99%) was dried by refluxing over CaH2. 

Ammonium acetate NH,C3H303 1.1 Barium bromide BaBCj -92... 

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