Mercurous compound

After inorganic mercuric salts are absorbed and dissociated into the body fluids and in the blood, they are distributed between the plasma and erythrocytes. Aryl mercuric compounds and alkoxy mercuric compounds are decomposed to mercuric ions, which behave similarly. 

Alkyl mercury compounds in the blood stream are found mainly in the blood cehs, and only to a smah extent in the plasma. This is probably the result of the greater stabhity of the alkyl mercuric compounds, as well as their pecuflar solubiUty characteristics. Alkyl mercury compounds affect the central nervous system and accumulate in the brain (17,18). Elimination of alkyl mercury compounds from the body is somewhat slower than that of inorganic mercury compounds and the aryl and alkoxy mercurials. Methylmercury is eliminated from humans at a rate indicating a half-life of 50—60 d (19) inorganic mercurials leave the body according to a half-life pattern of 30—60 d (20). Elimination rates are dependent not only on the nature of the compound but also on the dosage, method of intake, and the rate of intake (21,22). 

Merkuro-. mercurous, mercury (I), -azetat, n. mercurous acetate. mercury(I) acetate, -chlorld, n. mercurous chloride, mercury(I) choride. -chrom, n. (Pharm.) mercuro chrome, -jodid, n. n ercurous iodide, mer-cury(I) iodide. -nitrat, n. mercurous nitrate, mercury(I) nitrste. -oxyd, n. mercurous oxide, mercury(I) oxide, -salz, n. mercurous salt, mercury (I) salt, -sulfat, n. mercurouasulfate, mercury(I) sulfate, -sulfid, n. mercurous sulfide, mercury(I) sulfide, -verbindung, /. mercurous compound, mercury (I) compound. 

This transformation is not common, but given the proliferation of nitriles in organic chemistry, it is potentially quite useful. In the presence of mercuric compounds, tertiary nitriles can be reduced to the hydrocarbon with sodium cyanoborohy-... 

InSug O, Datar S, Koch CJ, Shapho IM, Shenker BJ. 1997. Mercuric compounds inhibit human monocyte function by inducing apoptosis evidence for formation of reactive oxygen species, development of mitochondrial membrane permeabflity transition and loss of reductive reserve. Toxicology 124 211-224. 

The mercuric ion, Hg2 +, which is obtained after oxidation in the red blood cells and other tissues, is able to form many stable complexes with biologically important molecules or moieties such as sulphydryl groups. The affinity of mercury for sulphydryl groups is a major factor in the understanding of the biochemical properties of mercuric compounds, resulting in interference with membrane structure and function and with enzyme activity. 

Less than 10% (probably around 2%) of ingested mercuric chloride is absorbed [1-4]. Upon high intake, the corrosive action of mercuric chloride may alter the permeability of the gastrointestinal tract, thereby enhancing absorption. In newborn rats a more effective absorption of mercuric compounds has been reported [5],... 

Enzymes are important targets for mercury [71], and sulphydryl-group-containing enzyme being more sensitive to mercuric compounds than a non sulphydryl-group-containing enzyme [72], Enzymes reported to be inhibited include phosphatases [73, 74], dehydrogenases [75,76] and hexokinases [71]. 

Practically all of the mercuric compounds are teratogenic in animals [241,242], Mercuric chloride thus induced cataracts and deaths in rat embryos [243]. In the human, mercuric chloride has been related to abortion [244, 245], possibly through the inactivation of placental sulphydryl enzymes. 

H2SO4 at 60° C. 4-Astatophenylalanine and 3-astato-4-methoxy-phenylalanine were obtained by subsequent reaction of the nonisolated mercurated compounds with At over a period of about 30 minutes. The respective radiochemical yields were on the order of 85 and 70% both astatoamino acids were identified by paper electrophoresis 166). 

Mercury Recovery Services, Inc. (MRS), has developed the Mercury Removal/Recovery Process (MRRP) to treat media contaminated with mercury. The ex situ process uses medium-temperature thermal desorption to remove the mercury from contaminated wastes. Process wastes are heated in a two-step process to recover metallic mercury in a 99% pure form. MRS claims MRRP can be applied to soils, activated carbon, mixed waste, catalysts, electrical equipment, batteries, lamps, fluorescent bulbs, mercurous and mercuric compounds, mercury-contaminated waste liquids, and debris. 

Methyloxadiazole and HgClg yield a complex XLIV. S-Phenyl-oxadiazole and HgCl gives directly the substituted derivative XLV. These mercurated compounds, on treatment with a halogen, yield the desired 5-halogeno-oxadiazoles 25a). 

Several mercurous salts absorb ammonia in the dry state or react with ammonia in aqueous solution. The products formed have been described from time to time as ammino-mercurous compounds. It appears, however, that these supposed mercuro-ammines are nonexistent, and that the substances produced by the action of ammonia are really mercuric derivatives mixed with mercury. For instance, mercurous fluoride in the dry state is blackened by ammonia gas, forming a compound HgF(NH3). This substance gives off ammonia at 100° C. and is black in colour the colour is now regarded as being due to finely divided mercury, and the compound as a derivative of mercuric fluoride and not of mercurous fluoride. Numerous instances of the same kind may be quoted. For example, mercurous chloride with aqueous ammonia yields a black compound this again has been proved to be a mixture of finely divided mercury and mercuric chloroamidc. The reaction may be represented thus ... 

In a similar way, aniline, the three toluidines, and the aminophenols can be converted into the corresponding chloro-mercuric compounds in about 40 per cent yields. 

A small amount of mercurous compounds is removed by the filtration. 

Much of the fundamental kinetic and mechanistic work on electrophilic substitution at saturated carbon has involved the study of reactions in which an organomercury substrate undergoes substitution by an electrophilic mercuric compound. Ingold and co-workers1 have concluded that these mercury-for-mercury exchanges occur only through the one-alkyl (1), the two-alkyl (2), and the three-alkyl (3) mercury exchange, viz. 

Jensen et al43 have confirmed both the stoichiometry of equation (17), and the fourth-order rate expression (18) for the symmetrisation of the tert.-butyl ester of a-carboxybenzylmercuric bromide in a study by nuclear magnetic resonance. The fourth-order rate coefficient remained constant at about 15 x 10-4 l3.mole-3. sec-1 at 31.4 °C over a wide range of initial concentrations of both the mercuric compound and of ammonia. Of mechanisms B and C, these workers preferred C. 

A number of substitutions of alkylgold complexes by mercuric compounds have been examined by Gregory and Ingold44. The SE1 substitution of 1-cyano-l-carbethoxypentyl(triphenylphosphine) gold(I) has been described in Chapter 4, Section 2.3 (p. 32) and in the present section those substitutions proceeding by bimolecular mechanisms are discussed. 

It seems to be certain that the oxynitration reaction in the presence of mercury salts proceeds through the formation of phenylmercuric nitrate. The isolation of phenylmercuric nitrate from a reaction mixture in dilute nitric acid by several authors (Carmack and his co-workers [135], Titov and Laptev [71], and also Bro-ders [124]) favours this view. If an intermediate nitroso compound is formed in the reaction its formation should be ascribed to the reaction between phenylmercuric nitrate and nitrous acid. This view, based on earlier experiments of Baeyer [136], Bamberger [137], Smith and Taylor [137a], has since been confirmed by Westheimer, Segel and Schramm [138], who considered the nitroso compound formed from an organo-mercuric compound to be the principal intermediate product in the Wolffenstein and Boters reaction. 

If nitric acid does not contain nitrogen oxides, a reversible decomposition of the organo-mercuric compound can take place, as has been shown by Baryshnikova and Titov [139] ... 

All mercuric compounds are extremely toxic, and thus there are health hazards associated with the use of the mercuric chloride-diphenyl car-bazone reagent. Testing should ideally be carried out in a fume cupboard, with standard safety procedures being observed, e.g. the use of rubber gloves, etc. In addition, there is the risk of potential contamination of the working area - this should be thoroughly cleaned after use. Finally, special precautions need to made with respect to the disposal of any waste materials after testing has been carried out. 

Various types of vessels have been described for the purpose of setting up calomel electrodes the object of the special designs is generally to prevent diffusion of extraneous electrolytes into the potassium chloride solution. In order to obtain reproducible results the mercury and mercurous chloride should be pure the latter must be free from mercuric compounds and from bromides, and must not be too finely divided. A small quantity of mercury is placed at the bottom of the vessel it is then covered with a paste of pure mercurous chloride, mercury and potassium chloride solution. The vessel is then completely filled with the appropriate solution of potassium chloride which has been saturated... 

Experiment i66. — (a) Mercurous. Add a few drops of hydrochloric acid to a little mercurous nitrate solution. The white precipitate is mercurous chloride. Note its insolubility in water and in dilute hydrochloric acid. Add a few drops of ammonium hydroxide. The black precipitate is mainly mercurous ammonium chloride. Its formation is a delicate test for mercury in mercurous compounds. 

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