Mercuric acetate, decomposition

The acid catalyzed hydration of olefins is frequently attended by decomposition or rearrangement of the acid-sensitive substrate. A simple and mild procedure for the Markovnikov hydration of double bonds has recently been devised by Brown and co-workers 13). This reaction, which appears to be remarkably free of rearrangements, initially involves the addition of mercuric acetate to the double bond to give the 1,2-... 

The hemidecarboxylation of sodium phthaiate on reaction with mercuric acetate in boiling water [Eq. (82), X = H] (90) was the first reported thermal decarboxylation. The reaction has been observed for a number of arenes with two adjacent carboxylate groups (1-4,91) and has been named the Pesci reaction (91). Studies of 3-substituted sodium phthalates or of preformed mercuric 3-substituted phthalates have shown that the sterically hindered carboxyl group (the 2-carboxyl) is preferentially eliminated whether X is electron-donating or electron-withdrawing [Eq. (82), X = Me (91), Cl, N02 (91,93), Br (93), or C02H (94)]. A similar conclusion was drawn from the decomposition of mercuric 1,2-naph-thalenedicarboxylate and 3,4-phenanthrenedicarboxylate (91). 

Barium acetate converts to barium carbonate when heated in air at elevated temperatures. Reaction with sulfuric acid gives harium sulfate with hydrochloric acid and nitric acid, the chloride and nitrate salts are obtained after evaporation of the solutions. It undergoes double decomposition reactions with salts of several metals. For example, it forms ferrous acetate when treated with ferrous sulfate solution and mercurous acetate when mixed with mercurous nitrate solution acidified with nitric acid. It reacts with oxahc acid forming barium oxalate. 

Jack Halpern I want to ask Dr. Dessy two questions. Sometime ago we looked at substantially the same reaction (i.e., decomposition of methoxycarbonyl mercuric acetate) in aqueous solution, and we found also that this decomposition is catalyzed by hydrogen ion and by chloride ion. The rate is first-order in (H+), but we found that in addition to a path first-order in (Cl-) there were also appreciable contributions from higher order paths, certainly second-order and possibly also third. This implies that the process is further aided by coordination of more than one halide to the metal. I wondered whether there were any corresponding indications in these solvent systems. 

A. J. Balard,9 in 1821, also prepared hypobromous acid in a similar manner, namely, by the gradual addition of mercuric oxide of bromine water, and thoroughly shaking the mixture after each addition. Further, quantities of bromine and mercuric oxide can be added until the yellow fluid contains between 6 and 7 parts of HOBr per 100 c.c. The mercuric oxide can be replaced by silver oxide, silver or mercuric nitrate, mercuric acetate, etc. The soln. with 6-7 parts of HOBr per 100 c.c. decomposes at 30°, but more dil. soln. when distilled under ordinary atm. press, give a distillate of bromine followed by a straw-yellow fraction which is a dil. aq. soln. of hypobromous acid. The decomposition is not so pronounced if it be conducted at 40° under a press, of, say, 50 mm. of mercury. 

The diethynyl compounds 26, 38 and 41 showed a different type of ring closure on thermal decomposition of their tetrachloroplatinate complexes to give the 3-phenylbenzofulvene derivatives 51, 52 and 53, respectively 53 was also quantitatively obtained by treatment of 41 with mercuric acetate in acetic acid-sulphuric acid . 

Mercuric chloride,mercuric bromide, and mercuric acetate form stable, solid complexes with thietanes which melt with decomposition. They are useful in the characterization of thietanes. No difficulty was experienced in the formation of complexes of 3-substituted thietanes even when the substituent was l-butyk but the 2,3-disubstituted thietane 89 did not give an isolable mercuric chloride complex. The superior complexing ability (relative to acyclic sulfides) of thietane was determined by partitioning thietane between heptane and saturated aqueous mercuric acetate. ... 

A suspension of 2 75 grams of 8-acetylamino-4-hydroxyphenylarsinic acid in 30 c.c. of ice-cold water is quickly dissolved by the addition of 11 c.c. of 2iV sodium hydroxide, then treated with an ice-cooled solution of 3-2 grams of mercuric acetate in 2 c.c. of acetic acid and 20 c.c. of water. After keeping in the dark for six to seven days, the yellowish-brown precipitate is washed with water and dried. Any unchanged arsinic acid is removed from the product by shaking witli methyl alcohol the yield is quantitative. The compound is not decomposed below 300° C. it is soluble in sodium carbonate, caustic alkali, and ammonia solutions. Saponification of the acid cannot be accomplished without decomposition. The position of the mercury has been proved by shaking the compound with iodine in potassium iodide, when 5-iodo-S-acetylamino-4i-hydroa yphenylarsinic acid results. 

Diacetoxymercuri phenol. —Phenol in concentrated aqueous solution is treated wdth mercuric acetate, wdien a w hite precipitate separates out, the reaction being accelerated if heat is applied. This product crystallises from dilute acetic acid in needles, M.pt. 216° to 217° C. The mother-liquor from this preparation contains o- and p-acetoxymercuri phenols.. Treatment of the diacetoxy compound with sodium chloride gives the dicMoromercuri phenol, a white powder, M.pt. 258° C. with decomposition. ... 

A solution of 2 8 grams of m-dimethylaminophenol in 10 c.c. of alcohol is mixed with 7 grams of 90 per cent, mercuric acetate in 30 c.c. of water. A jelly forms, and this when heated for two minutes on the water-bath melts, and yellow crystals separate. The precipitate is collected, washed with vater, and dried in vacuo. Yield 7 4 grams, 92 per cent. It forms dirty yellow crystals, insoluble in the usual solvents, except pyridine. It dissolves in sodium hydroxide, and the solution may be boiled without decomposition. In water it only dissolves to a slight extent, the solution giving mercuric sulphide on addition of ammonium sulphide. When the dry product stands for two weeks metallic mercury separates out. If the substance is slowly heated it melts with decomposition at 100° to 110° C. 

Diacetoxymercuri-o-cresol (IIL),— The yield of the product may be increased by raising the temperature in the above reaction or by using 2 mols. of mercuric acetate. The diacetoxy compound melts with decomposition at 192° to 195° C., and yields aiid... 

A solution of thiosalieylie acid in alcohol is treated with water until faint turbidity is produced, then an aqueous solution of mercuric acetate (1 5 mols.) slowly added. The precipitate is boiled with alcohol to remove impurities, then treated vith a mixture of ammonium hydroxide and carbonate until complete solution is obtained. The latter is filtered hot, and treated with acetic acid until faintly opalescent. On cooling, the anhydride crystallises in pale yellow, microscopic rods. Yield 50 per cent. When boiled with a concentrated solution of sodium chloride, and the solution filtered and treated with acetic acid, impure o-chloromercuri ihioWenzoic acid is precipitated. When the latter compound or the anhydride are dissolved in concentrated ammonium hydroxide, a substance crystallising in plates, M.pt. 206° C. with decomposition, is produced. Its formula corresponds to C HieOfjNgSgHgg. Some niercuri-bis thiolbenzoic acid is also formed. 

Two grams of the ethyl ester (1 mol.) in 10 c.c. of metliyl alcohol are added to 8 grams of mercuric acetate (2 mols.) in 50 c.c. of the same solvent, and the mixture allowed to stand for a day. A pale yellow, non-crystalline product separates out, and this is filtered and washed with methyl alcohol and ether. Yield 7 7 grams, 93 per cent. It cannot be rccrystallised, melts about 245 C., and is soluble in ammonium hydroxide, acetic add or mineral acids, but with decomposition in latter in the usual organic solvents it is practically insoluble. Its acetic acid solution after neutralisation with ammonium hydroxide splits off mercuric sulphide when treated with cold ammonium sulphide. 

Acetoxymercuri - benzeneazo - p - cresol/ C H5.N2.C7H5(OH). Hg.OAc.—Mercuric acetate in very dilute acetic acid is boiled under retiux with alcoholic benzeneazo-]>-cresoi for seven hours. It is purified by fractional precipitation from its acetic acid solution by water, and recTVst alii sat ion from glacial acetic acid. It crystallises in red-brown needles, M.pt, 2f>9" to 270 C. with decomposition, and has similar solubilities to tiie above compounds. Its chloride melts with decomposition at 246 to 248 C. Dimroth prepared these compounds from acetoxymereuri-p-cresol and benzene diazonium chloride. ... 

Furukawa, N. and K. Tonomura. 1971. Enzyme system involved in the decomposition of phenyl mercuric acetate by mercury-resistant Pseudomonas. Agric. Biol. Chem. 35 604-610. 

MERCURIALIN or MERCURIALIN SOLUTION (74-89-5) see methylamine. MERCURIC ACETATE (1600-27-7) Light and heat and can cause decomposition. May react violently or form sensitive explosive con5)ounds with 2-butyne-1,4-diol, fluoroacetylene, a-nitroguanidine, 5-nitrotetrazol, and others. Incompatible with ammonia, hydrozoic acid, methyl isocyanoacetate, sodium acetylide, sodium peroxyborate, trinitrobenzoic acid, urea nitrate. 

Mercury fulminate is relatively resistant to the action of dilute acids, in particular to that of nitric acid, but concentrated acids cause decomposition. Thus, under the influence of nitric acid decomposition occurs with evolution of NO, CO, acetic acid and mercuric nitrate. Under the influence of concentrated hydrochloric acid free fulminic acid is evolved (with an odour resembling that of hydrogen cyanide) as well as the decomposition products hydroxylamine hydrochloride, formic acid, mercuric chloride (Carstanjen and Ehrenberg [32] Scholl [33]). Mercury fulminate explodes on direct contact with concentrated sulphuric acid. 

Aqueous solutions of organic acids such as formic, acetic, and oxalic, decompose mercury fulminate, forming the corresponding mercuric salts. On the other hand, the action of dilute inorganic acids involves decomposition with formation of C02. 

E. P. Alvarez 2 found that the pemitrates react with soln. of lead acetate (white precipitate), silver nitrate (white precipitate), mercurous nitrate (white precipitate with rapid decomposition), mercuric chloride (red precipitate), copper sulphate (blue precipitate), zinc and cadmium sulphates (white precipitate), bismuth nitrate (white precipitate), gold chloride (slight effervescence and escape of oxygen), manganous chloride (pink precipitate), nickelous chloride or sulphate (greenish-white precipitate), cobaltous nitrate and chloride (pink precipitate), ferrous sulphate (green or bluish-green precipitate), ferric chloride (red ferric hydroxide), and alkaline earth chlorides (white precipitates). The precipitates are all per-salts of the bases in question. 

The former is deposited in yellow crystals, mixed with sulphur when acetoxime is treated with phosphorus pentasulphide in carbon bisulphide soln. the insoluble product extracted with alcohol and the alcoholic soln. heated to boiling the compound separates from cold water in large, transparent, seemingly monoclinic prisms, melts at 146° 150° with decomposition, and is readily soluble in water, but only sparingly in alcohol, and insoluble in ether and carbon bisulphide. It decomposes carbonates, gives a colourless precipitate with lead acetate, and is decomposed by hot dilute nitric acid with separation of sulphur and formation of phosphoric acid it is also decomposed by mercuric oxide, the filtrate from the precipitated mercury sulphide giving all the reactions of phosphoric acid. 

Other metals, the commonest being lead,2 bismuth, and manganese, in powder form exert a more moderate effect on the decomposition. Mercury would also fall into this class of moderate accelerators, but the catalytic action in this case is remarkable in being periodic or rhythmic. When the concentration of hydrogen ion is reduced to an almost negligible quantity by the addition of a little sodium acetate solution, a clean mercury surface in contact with hydrogen peroxide solution of approximately 10 per cent, concentration, at periodic intervals of about one second, becomes coated with a bronze film which suddenly disappears with a burst of oxygen from the contact layer of the two liquids the substance of the film, which is alternately formed and decomposed, is probably an unstable oxide, possibly mercurous peroxide.3... 

This results in 63 per cent, yield when the same quantities of materials are used as in the preceding preparation, the 2-bromo-6-methylphenyl-arsinic acid being replaced by 2-bromo-4-methylphenylarsinic acid. The compound crystallises in colourless needles, melting with decomposition at 158° to 159° C., readily soluble in acetic acid, methyl and ethyl alcohols, and acetone, very sparingly soluble in water. The sodium, potassium and ammonium salts are readily soluble in water the silver, mercuric and lead salts form white, flocculent precipitates, insoluble in cold or hot water the silver salt is soluble in ammonia the mercurous, calcium and barium salts arc white precipitates, insoluble in cold but soluble in hot water. The magnesium salt is obtained when a solution of the ammonium salt is boiled with magnesia mixture. 

Acetoxymercuriformic ethyl ester is prepared by the action of carbon monoxide on an ethyl alcohol solution of mercuric chloride, but the absorption takes three times as long as in methyl alcohol. The compound sinters at 65° C. and melts at 125° C. It is easily soluble in acetone, chloroform, or ethyl acetate, less so in warm water, ether, or benzene, sparingly in cold water, and insoluble in ligroin or petroleum ether. It crystallises in w arty needles. The chloride crystallises in plates, melting at 88° C. with decomposition the bromide and iodide are similar compounds. A sulphide has also been obtained as a yellowish-white precipitate. 

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