Mercury-bromoform

In addition to the chemicals included on the other lists, the CDC also included heavy metals such as arsenic, lead, and mercury volatile solvents such as benzene, chloroform, and bromoform decomposition products such as dioxins and furans polychlorinated biphenyls (PCBs) flammable industrial gases and liquids such as gasoline and propane explosives and oxidizers and all persistent and nonpersistent pesticides. Agents included in this volume are limited to those that are most likely to pose an acute toxicity hazard. 

The slight solubility of yellow phosphorus in several other liquids has been notioed— e.g. ethyl chloride, ethylene chloride, chloroform, bromoform, ohloral, acetic ether, acetone aldehyde, cacodyl sulphide, allyl thiooyanate, mercury methide, valerianic acid, amyl valerate, fusel oil, benzoyl chloride, stannic chloride, ethyl nitrite, nicotine, coniine, cavutchin, styrene, aniline, quinoline, creosote, etc. J. Hartmann found that 100 grms. of bile at 38-5° dissolved 0 02424 grm. of phosphorus, and more at a higher temp. 

Silicobromoform is usually prepared by passing hydrogen bromide over heated silicon112,4,5 or a silicide such as copper silicide.3 The product, consisting of a mixture of silicon tetrabromide with a few per cent of tri- and dibromosilanes, is purified by shaking with mercury, if necessary, to remove any free bromine, and by fractional distillation. The use of metal silicides instead of silicon does not add appreciably to the yield of the bromoform and is not recommended in the following procedure. 

Aluminium, antimony, arsenic, barium, beryllium, boron, bromodichloromethane, bromoform, cadmium, chromium, copper, dibromochloromethane, iron, lead, manganese, mercury, molybdenum, nickel, selenium, uranium, zinc Nitrate... 

Antimony, boron, bromoform, chloral hydrate, chloroform, iron, lindane, mercury, nitrilotriacetic acid, trichloroethene, zinc... 

Preparation. Reutov and Lovtsova prepared phenyl(trichloromethyl)mercury (II) by reaction of phenylmercuric chloride with potassium r-butoxide and chloroform in benzene. Use of bromoform affords I. Seyferth and Burlitch, who carried... 

ETHANE PENTACHLORIDE (76-01-7) CHCljCClj Noncombustible liquid. Incompatible with water, producing dichloroacetic acid. May self-ignite in air. Incompatible with strong oxidizers. Contact with aluminum, cadmium, mercury, hot iron, alkalis, alkali metals causes dehologenation, forming chloroacetylene gas which is spontaneously explosive in air. Contact with potassium may explode (after a short delay) or form shock- and friction sensitive materials. Incompatible with potassium-sodium alloy + bromoform reaction may be violent. 

Ring expansion of I-methylindenes. Gillespie et al have described a convenient synthesis of phenyl(tribromomethyl)mercury by mixing phenylmercuric chloride, sodium hydride, and bromoform in benzene with methanol as initiator. They have converted l-methyUndenes into 3-bromo-l-methylnaphthalenes by reaction with dibromocarbene generated from this precursor. Reaction of 1-methylindenes with dibromocarbene generated from bromoform with base... 

Examples of toxic compounds, including some important intermediates and starting materials in the chemical industry, are shown in Figure 3.3. Many alkali fluorides, such as alkali hexafluorosilicate, alkali hydrogen difluoride, or alkali sulfuryl fluoride, are well known toxic substances. Sulfur dioxide and ammonia (ubiquitous gases) are toxic, as are chlorine, metallic mercury vapors, many organic phenol compounds, amino aromatic compounds such as aniline, and many substituted amino-benzene derivatives. Additionally, many diisocyanates are toxic, e.g., 2,4- and 2,6-toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), chloro-, bromo-, and iodoacetic acid, methyl bromide, tribromomethane (bromoform), carbon tetrachloride, and formaldehyde. Also, many natural compounds present in many plants have toxic properties, and a selection of these are listed in Table 3.4. 

There are no significant differences between dichloro- and dibromocarbene in terms of preparation methods. Synthetic considerations, however, make the reaction products of dibromocarbene more desirable. Procedures using bromoform and phenyl(tribromo methyl)-mercury 0 starting materials are well known. However, the most often followed and best route to dihalocarbenes is without doubt the phase-transfer method (PTC). l The reaction is usually carried out as a liquid-liquid two-phase basic system. From bromoform. 

These composite liquids consist of a dispersion of dense metal particles (e.g., ferrosilicon, mercury) or powdered heavy minerals (e.g., magnetite, barite) into a liquid (e.g., water, bromoform). Such heavy suspensions are either used in the laboratory or for commercial benefit or in the field . Certain companies (e.g., Cargille New Jersey, USA) have commercialized dense liquors with densities up to a specific gravity of 7 but they are not stable, are opaque and can only separate minerals with large grain of few millimeters satisfactorily. However, Desnoes inspired by the work of Orphy prepared suspensions of microdroplets of mercury (10 pm) into bromoform that provided better results. 

Qiloroform yields both the trichloromethyl anion and dichlorocarbene as reactive intermediates under basic phase transfer conditions. The trichloromethyl anion reacts with phenylmercuric chloride under these conditions to yield phenyl(trichloromethyl)-mercury (72%). The product is unstable, however, to the 50% aqueous sodium hydroxide solution usually used in phase transfer catalysis. When 10—15% aqueous sodium hydroxide solution was used, while maintaining the ionic strength by addition of potassium fluoride, the product survived. Reasonable yields of the mercury compound were thus obtained and the reaction was successfully extended to bromodichloromethane [yielding 64% of phenyl(bromodichloromethyl)mercury] and bromoform [yielding phenyl(tribromomethyl)mercury, 54%]. The transformation is illustrated in equation 3.18 [26]. 

Subsequent to the 1982 compilation of Lounila and Jokisaari [237], a large number of studies report chemical shift anisotropies for various nuclei in liquid crystalline solvents. Representative examples include ACTh in dichloromethylphosphine [243], methylisothiocyanide [244], and norborna-diene [141] A(Tc in chloro- and bromoform [245], bis(trimethylsilyl)diacetylene [246], and pyridine, pyrazine, pyridazine, and pyrimidine [247] ACTh and ACq in butyne [248], fluoro- [245,249], bromo- [245], and iodomethane [244, 245, 250], ethylene [251], methylisocyanide [252], dimethyl-mercury [253], benzene [250, 254, 255], 1,3,5-trichloro- [99, 256], 1,3,5-tribromo-[244], and 1,3,5-trinitrobenzene [244] Afluoro-methane [249] Aa in dimethylmercury [253] AcTsein carbon diselenide [258] AcTje in tellurophene [259] and AOxe [260]. 

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