Mercury halos

The extraction of metal ions depends on the chelating ability of 8-hydroxyquinoline. Modification of the stmcture can improve its properties, eg, higher solubility in organic solvents (91). The extraction of nickel, cobalt, copper, and zinc from acid sulfates has been accompHshed using 8-hydroxyquinohne in an immiscible solvent (92). In the presence of oximes, halo-substituted 8-hydroxyquinolines have been used to recover copper and zinc from aqueous solutions (93). Dilute solutions of heavy metals such as mercury, ca dmium, copper, lead, and zinc can be purified using quinoline-8-carboxyhc acid adsorbed on various substrates (94). 

Dr M Harris ICI Halo chemicals, PO Box 13, The Heath, Runcorn, Cheshire, WA7 4QP, UK. Phase-out Issues for Mercury Cell Technology in the Chlor-Alkali Industry. 

Although the description fulminating is not used and thus confusion with the fulminate not caused, mercury also forms explosive compounds of similar nature. The nitride (ibid.) is the most common and can be formed from the metal and ammonia in some circumstances, causing accidents where mercury manometers are used with ammonia. Halo-hydroxy- and oxy-nitrides can also be involved [3], See METAL FULMINATES, GOLD COMPOUNDS, A-METAL DERIVATIVES, PRECIOUS METAL DERIVATIVES, SILVER COMPOUNDS... 

There are three important routes to the formation of the mercury-transition metal bond (a) displacement of halogen or pseudohalogen from mercury(II) salts with carbonyl metallate anions (b) reaction of a halo-phenylmercury compound with a transition metal hydride and (c) oxidative addition of a mercury halide to neutral zero valent metals.1 We report here the syntheses of three compounds containing three-centre, two-electron, mercury-ruthenium bonds utilizing trinuclear cluster anions and mercury(II) halides.2-4... 

Ring contraction of coumarins is used for the preparation of benzo[Z>]furans. Alkaline degradation of the 3-halo-, 4-halo- or 3,4-dihalo-coumarins gives the coumarilic acids (Scheme 104). The coumarilic acids are decarboxylated to the corresponding benzo[Z> ]f urans. Basic mercury(II) oxide oxidation of 4-phenylcoumarin (neoflavanoid) yields the 3-phenyl-benzo[/>]furan (71IJC1316). 

Halo(formylmethyI)mercury, AA55 a-(Ha 1omercur i c)aceta1dehyde,... 

Suitable candidates for a-elimination reactions are silylmethyl halides (— base-induced elimination of H-Hal), silylmethyl dihalides (— halide/metal exchange followed by elimination of a metal halide) and stable carbenoid-type compounds such as (a-halo-a-silylalkyl)mercury compounds (— thermal elimination of mercury(II) halide). Bis(phenylthio)(trimethylsilyl)methyl lithium (— elimination of LiSPh) represents a borderline case (see Section III.E.8). 

Tellurolates replace chloride in transition metal halo complexes, in copper(I) chloride and in mercury(II) chloride. 

The photolysis of (Me3Si)3SiPh in the presence of functional substituted olefins is of considerable interest (55). Irradiation of 20 with a low-pressure mercury lamp in the presence of vinyl chloride or l-bromo-2-methyl-propene affords the respective 1-alkenyl-1-halo-1-phenyltrimethyldisilanes as the sole volatile product. The fact that the reaction of trimethylsilylphenylsilylene with butyl bromide does not give any volatile products suggests that compound 23 and 24 must come from a 1,2-halogen shift of... 

Other Lewis Acids. Several relatively weak Lewis acids such as zinc halides and mercury halides initiate polymerization of the most reactive monomers such as N-vinyl carbazole, vinyl ethers, and alkoxysty-renes. Many of these acids have poor solubility in hydrocarbons and halo-genated hydrocarbons and are therefore used as acetone or ether solutions. However, such solvents act as nucleophiles, and therefore decrease the acids Lewis acidity. 

Depending on the mode of generation, a carbene may be initially formed in either the singlet or triplet state, irrespective of its stability. Common methods used for the generation of carbenes include photolytic, thermal, or metal catalyzed decomposition of diazocompounds, elimination of halogenfrom gem-dihalides, elimination of Hx from CHX3, decomposition of ketenes, thermolysis of a-halo-mercury compounds and cycloelimination of shelf stable substrates such as cyclopropanes, epoxides, aziridines and diazirines. 

The method has been of particular value in the preparation of difunctional compounds. For example, the action of elemental halogen on sodium acetylides or alkynylmagnesium halides gives 1-halo-1-alkynes (70-90%). t Also, halo esters, phenols, or acids result when the appropriate aromatic mercurial is treated. Sometimes p-toyl-sulfonyl chloride is substituted for chlorine gas. p-Iododimethylaniline is easily made in 42-54% yield by the reaction of p-dimethylaminophenyl-lithium and iodine. ... 

Mercury bis[pentafluorotelluro(trifluoromethyl)amide] reacted with elemental halogens and interhalogens to yield halo(trifluoromethyl)amino tellurium pentafluoride The less electronegative halogens of the interhalogens Join the amide-nitrogen atom. 

The reduction of chiral 1-substituted l-halo-2,2-diphenylcyclopropanes at a mercury cathode to the chiral cyclopropanes has been reported by some workers [387-389]. 

Meyers approach to a-chiral lactones may be expanded to the 8-lactone series with ee values comparable to those achieved for lactones (equation 118). Mercuri- and similarly halo-lactonizations of 8,8-unsaturated carboxylic acid derivatives are an efficient way to achieve stereocontrolled heteroatom-carbon ring closure, e.g. of (333) to (334 equation 1IQ). ... 

Mercury, by virtue of its coexistence with many types of base metal and precious metal deposits and its high vapour pressure, often forms secondary halos above ore deposits, including in soils. When soil is heated, Hg is released at different temperatures according to the form in which it occurs in the soil (Fig. 13-1). The choice of a particular temperature for thermal release of Hg in a certain form can produce geochemical data that are useful for locating deep blind ore deposits. Comparison of data obtained by thermal release at different temperatures allows the discrimination of significant anomalies related to such mineralisation from false anomalies related to various forms of pollution. 

Friedrich, G.H. and Hawkes, H.E., 1966. Mercury dispersion haloes as ore guides for massive sulphide deposits. West Shasta District, California. Mineral. Deposita, 2 77-88. 

Fursov, V.Z., 1958. Halos of dispersed mercury as prospecting guides at the Achisai lead-zinc deposits. Geochemistry, 3 338-344. 

Ozerova, N.A., 1962. Primary dispersion haloes of mercury. Acad. Sci. USSR, Inst. Geol. Ore Deposits, Petrography, Mineralogy and Geochem., Proc. 72,135 pp. (in Russian). 

Ozerova, N.A., 1971. Primary dispersion haloes of mercury. IGR Book, Section 13, 109 pp. 

Reactions of the mercurial with halogens or interhalogens lead to the formation of a series of pentafluorosulfanyl iV-halo(trifluoromethyl) amines, SFgNlXlCFa (X = F, Br, Cl, I) 210). 

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