Mercury salts, basic

Whereas metal salts of carboxyUc acids cataly2e the above reactions, these are not sufftciendy basic to cleave Si—H bonds. Mercury salts of organic acids in the presence of silver perchlorate, however, do react to produce organoacyloxysdanes (111). 

C. Sulfamates prepared from weak bases form acidic solutions, whereas those prepared from strong bases produce neutral solutions. The pH of 5 wt % solution of ammonium sulfamate is 5.2. Crystals of ammonium sulfamate deliquesce at relative humidity of 70% and higher. Both ammonium sulfamate [7773-06-0] and potassium sulfamate [13823-30-2] hbemte ammonia at elevated temperatures and form the corresponding imidodisulfonate (12). Inorganic sulfamates are quite water-soluble, except for the basic mercury salt. Some relative solubilities of sulfamates at 25°C in 100 g of water are ammonium, 103 g sodium, 106 g magnesium, 119 g calcium, 67 g barium, 34.2 g zinc, 115 g and lead, 218 g. The properties of a number of sulfamates may be found in the literature (see Table 5). 

When ethylene was passed into a basic solution of Hg(OAc)2 containing a catalytic amount of [Rh2(OH)3(C5Me5)2]+, ethanol was formed.617 It appears that mercury salts of the type HOCH2CH2HgOAc are formed in a stoichiometric reaction so that this is not strictly a catalytic activation of ethylene by the rhodium complex. 

Nonconjugated dienes or polyenes can be monomercurated if the diene or polyene is employed in excess, but more frequently these compounds are allowed to react with an excess of the mercury salt and di- or poly-mercurated products are obtained. The relative reactivity of isolated double bonds is basically that expected from studies on simple alkenes. 

Lead and mercury yield basic salts, PbPt(NOo) L.Pb(OH)2 and 2Hg2Pt(NOa)2Ia.Hg20.9H2O. 

PRINCIPIA — Principles are those things whence a substance is produced in any genus of composites. These primes, or principles, because of their immanence, have a certain basic substance, wherein they flourish, and whereby they are produced. They are not those of Aristotle, which are not primeval substances, but, as the types of every genus, have at the same time an analogy with our principles. The properties of principles are based sometimes in the elemental and sometimes in the celestial region. Accordingly, they sometimes resemble elements, and at other times essences. These principles are three — Mercury, Salt, Sulphur. 

Acetylene is condensed to vinylacetylene and divinylacetylene by cuprous chloride and ammonium chloride. Similar additions of other compounds containing an active hydrogen atom occur in the presence of various catalysts. Mercury salts ate most effective in the vapor-phase reaction of acetylene with hydrogen chloride to give vinyl chloride (100%). Basic catalysts such as potassium hydroxide, potassium ethoxide, or zinc oxide are used for the vinylation of alcohols, glycols, amines, and acids. Most of these reactions involve the use of acetylene under pressure, and few have been described as simple laboratory procedures. Chloroacetic acid, however, reacts with acetylene at atmospheric pressure in the presence of mercuric oxide to yield vinyl chloro-acetate (49%). ... 

This is in accordance with the general properties and isomorphic relations of the acid and its salts, but such a formula indicates a deea-basic acid, whereas, with the exception of an ill-defined mercury salt (see p. 239), only hexabasicsalts, M 3H4[H2(W207)g], have been obtained. Even with such a weak base as dimethylpyrone, the salt produced is... 

Biaryls can also be derived (7(>-90%) from mercury salts, ArHgX, using methodology very similar to a normal Ullmann coupling (copper powder, pyridine, reflux), except that a catalytic amount of PdCh is alsorequired. Less basic solvents do not lead to such good yields, but otherwise the reaction charac-... 

Basic Mercury Salts.—The Phase Rule has also been applied by A. J. Cox in an investigation of the basic salts of mercury, the result of which has been to show that, of the salts mentioned in text-books, quite a number are incorrectly stated to be chemical compounds or chemical individuals (p. 70). The investigation, which was carried out essentially in the manner described above, included the salts mentioned in the following table and of the basic salts said to be derived from them, only those mentioned really exist. In the following table, the numbers in the second column give the minimum values of the concentration of the acid, expressed in equivalent normality, necessary for the existence of the corresponding salts in contact with solution at the temperature given in the third column. 

Other types of organic mercury derivative are formed by addition of mercury salts to olefins 192 for example, when ethylene is passed into an aqueous mercuric acetate solution, a basic mercury salt adds to the C=C double bond ... 

Mercury(II) salts react with alkynes in two different ways. As discussed in Section 2.2, terminal alkynes react with mercury under basic conditions to yield species with general formula Hg(C=CR)2 or Hg(X)(C=CR). Alternatively, under neutral or acidic conditions, alkynes undergo solvomercuration reactions to yield anti addition products (for example, see equation 17). ... 

Berthollet obtained various (basic) sulphates of mercury and concluded that instead of there being only two sulphates, one with the minimum and the other with the maximum of oxygen, these were only the two extremes of a continuous series of salts (between the mercurous and mercuric). Between the salt of mercury obtained by dissolving the metal in cold dilute nitric acid (mercurous nitrate) and that formed with hot nitric acid (mercuric nitrate) all intermediate proportions may exist. He quotes Fourcroy and Bayen. Proust showed that these are all mixtures of two kinds of mercury salts only, which had been recognised by Scheele (p. 230). 

Unfortunately, the yield of MF is too low (only about 5 %) because the majority of the mercuric salt of nitromethane is converted into a basic mercury salt of formhydroxamic acid (also an explosive). This mercury salt cannot be converted into MF [2]. The nitromethane itself can also be converted into fulminic acid by nitrosation with nitrous acid to form nitroformaldehyde oxime. It further decomposes (by heating in water or nitric acid) to fulminic acid which is trapped with mercury nitrate as mercury fulminate [2]. 

Neutral plasmalogens are related compounds in which position 1 of L-glycerol is linked by a vinyl ether bond (the double bond is of the c s-configuration) to an alkyl moiety. They have been detected in small amounts only in a few animal tissues. Although the vinyl ether linkage is stable to basic hydrolysis conditions, it is disrupted by acid (and by mercury salts) with the formation of a long-chain aldehyde, i.e. 

Since protamine is strongly basic, it forms salt-like complexes with various inorganic and organic acids. The sulfate, hydrochloride, nitrate, phosphate, and acetate salts are soluble in water, but the picrate, flavianate, and phosphotungstate salts are almost insoluble in water. Protamines also form scarcely soluble salts with silver nitrate, copper salts, mercury salts, etc. (Kossel, 1929). When heated to 60 °C with the Mirsky histone reagent (0.34 M mercuric sulfate in 1.88 M sulfuric acid) (Daly et al., 1951), protamine and histone are not precipitated whereas many other proteins precipitate. If the mixture is cooled to 0°C, the mercury salt of protamine is precipitated but histone remains in solution. This phenomenon can be utilized to distinguish protamine from histone. 

The ability of mercury salts to effect nucleophilic alkene addition is apparent in Lin and coworkers synthesis of the phorboxazole D ring (Scheme 26) [39]. Initial attempts at cyclization proceeded by addition to a halo-activated alkene. The use of iodine under basic conditions afforded the desired THP in 46 % yield as a 2.6 1 ratio of cisitrans isomers. The use of bulkier NIS increased the diastereoselectivity to 7.7 1 with no increase in yield. A more efficient cyclization was realized by using mercury(II) acetate. Installation of the iodide was accomplished by the addition of iodine after cyclization was complete. These conditions gave 2,6-cis THP 77 in 86 % yield and moderate diastereoselectivity (5 1). This method also benefits firom the displacement of the organomercurial intermediate in a single-pot procedure, thereby mitigating the isolation of potentially toxic mercury-containing substrates. 

Mercury T) sulphate. HgjSO formed by precipitation or excess Hg plus H2SO4. Hydrolysed to basic salts. 

Acid amides have weakly amphoteric properties, and thus give salts such as CjHsCONHj.HCl with strong acids, and salts of the type C HsCONHNa with strong bases. These compounds have to be prepared at low temperatures to avoid hydrolysis, and are difficult to isolate. The mercury derivatives can, however, usually be readily prepared, because mercuric oxide is too feebly basic to cause hydrolysis of the amide, and the heavy mercuric derivatives crystallise well. 

Mercurous Nitrate. Mercurous nitrate [10415-75-5] Hg2N20 or Hg2(N02)2, is a white monoclinic crystalline compound that is not very soluble in water but hydrolyzes to form a basic, yellow hydrate. This material is, however, soluble in cold, dilute nitric acid, and a solution is used as starting material for other water-insoluble mercurous salts. Mercurous nitrate is difficult to obtain in the pure state directly because some mercuric nitrate formation is almost unavoidable. When mercury is dissolved in hot dilute nitric acid, technical mercurous nitrate crystallizes on cooling. The use of excess mercury is helpful in reducing mercuric content, but an additional separation step is necessary. More concentrated nitric acid solutions should be avoided because these oxidize the mercurous to mercuric salt. Reagent-grade material is obtained by recrystaUization from dilute nitric acid in the presence of excess mercury. 

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