Lead chloride tetrachloride

Lead chloride, 4112 Lead(II) fluoride, 4329 Lead tetrachloride, 4172 Magnesium chloride, 4081 Manganese(II) chloride, 4085... 

Precipitate a little lead chloride by adding hydrochloric acid to a solution of lead nitrate. Describe its properties and compare them with those of lead tetrachloride (reference books). To what oxide of lead does lead tetrachloride correspond ... 

McLaughlin, D.R and Stoltz, R.A. (1988) Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent. US Patent 4737 244. 

Assemble in a fume-cupboard the apparatus shown in Fig. 67(A). Place 15 g. of 3,5-dinitrobenzoic acid and 17 g. of phosphorus pentachloride in the flask C, and heat the mixture in an oil-bath for hours. Then reverse the condenser as shown in Fig. 67(B), but replace the calcium chloride tube by a tube leading to a water-pump, the neck of the reaction-flask C being closed with a rubber stopper. Now distil off the phosphorus oxychloride under reduced pressure by heating the flask C in an oil-bath initially at 25-30, increasing this temperature ultimately to 110°. Then cool the flask, when the crude 3,5-dinitro-benzoyl chloride will solidify to a brown crystalline mass. Yield, 16 g., i.e,y almost theoretical. Recrystallise from caibon tetrachloride. The chloride is obtained as colourless crystals, m.p. 66-68°, Yield, 13 g Further recrystallisation of small quantities can be performed using petrol (b.p. 40-60°). The chloride is stable almost indefinitely if kept in a calcium chloride desiccator. 

Method 1. Equip a 1 litre three-necked flask (or bolt-head flask) with a separatory funnel, a mechanical stirrer (Fig. II, 7, 10), a thermometer (with bulb within 2 cm. of the bottom) and an exit tube leading to a gas absorption device (Fig. II, 8, 1, c). Place 700 g. (400 ml.) of chloro-sulphonic acid in the flask and add slowly, with stirring, 156 g. (176 ml.) of pure benzene (1) maintain the temperature between 20° and 25° by immersing the flask in cold water, if necessary. After the addition is complete (about 2 5 hours), stir the mixture for 1 hour, and then pour it on to 1500 g. of crushed ice. Add 200 ml. of carbon tetrachloride, stir, and separate the oil as soon as possible (otherwise appreciable hydrolysis occurs) extract the aqueous layer with 100 ml. of carbon tetrachloride. Wash the combined extracts with dilute sodium carbonate solution, distil off most of the solvent under atmospheric pressure (2), and distil the residue under reduced pressure. Collect the benzenesulphonyl chloride at 118-120°/15 mm. it solidifies to a colourless sohd, m.p. 13-14°, when cooled in ice. The yield is 270 g. A small amount (10-20 g.) of diphen3 lsulphone, b.p. 225°/10 mm., m.p. 128°, remains in the flask. 

Manufacture. Trichloromethanesulfenyl chloride is made commercially by chlorination of carbon disulfide with the careful exclusion of iron or other metals, which cataly2e the chlorinolysis of the C—S bond to produce carbon tetrachloride. Various catalysts, notably iodine and activated carbon, are effective. The product is purified by fractional distillation to a minimum purity of 95%. Continuous processes have been described wherein carbon disulfide chlorination takes place on a granular charcoal column (59,60). A series of patents describes means for yield improvement by chlorination in the presence of dihinctional carbonyl compounds, phosphonates, phosphonites, phosphites, phosphates, or lead acetate (61). 

Several modifications of the Simmons-Smith procedure have been developed in which an electrophile or Lewis acid is included. Inclusion of acetyl chloride accelerates the reaction and permits the use of dibromomethane.174 Titanium tetrachloride has similar effects in the reactions of unfunctionalized alkenes.175 Reactivity can be enhanced by inclusion of a small amount of trimethylsilyl chloride.176 The Simmons-Smith reaction has also been found to be sensitive to the purity of the zinc used. Electrolytically prepared zinc is much more reactive than zinc prepared by metallurgic smelting, and this has been traced to small amounts of lead in the latter material. 

The presence of sulfur compounds, especially thiophene, in the reagents leads to low yields and a dark-colored product. A good grade of thiophene-free benzene should be used. The benzene may be dried by distillation or by allowing it to stand over calcium chloride. The benzene which is recovered in this preparation may be used in future runs after it has been extracted with alkali, washed, and dried. Small amounts of carbon tetrachloride in the benzene do not interfere, since the quantities of benzene and carbon tetrachloride used are in excess of the relative quantity of the aluminum chloride. 

Carbon tetrachloride is a solvent that is chemically inert, highly resistant to oxidation, but biologically toxic. Despite its chemical stability, P450 is able to convert carbon tetrachloride to several reactive species. Reduced P450 transfers an electron to chloride leading to the elimination of a chloride anion and the generation of the reactive trichloromethyl radical (10). Trichloromethyl radical can undergo a second one-electron reduction to... 

Sodium hydride Sodium hydrosulfite Sulfur chlorides Sulfuric acid Sulfuryl chloride Tetraethyl lead Tetramethyl lead Thionyl chloride Titanium tetrachloride Toluene diisocyanate Trichlorosilane Triethylaluminum Triethylborane Triisobutylaluminum Trimethylaluminum Trimethylchlorosilane Tripropyl aluminum Vanadium tetrachloride Vinyl trichlorosilane Zirconium tetrachloride... 

We might expect that the reaction would lead to the formation of tetraphenylmethane from benzene and carbon tetrachloride in the presence of aluminium chloride, but this is not so. In this case the fourth Cl-atom remains in the reaction product. Triphenylchloromethane (C6H5)3CC1 has acquired extraordinary importance because, when applied in the Wurtz reaction, it made possible the discovery of the first free organic radicle (Gomberg, 1900). Compare p. 352. 

Dauben et al. found that the CCI3 radical produced by sonolysis of carbon tetrachloride can be used in a decarboxylation-halogenation sequence (Scheme 3.5) [43]. Sonication of a thiohydroxamic ester at 33 °C for 10 - 50 min in carbon tetrachloride leads to the corresponding chloride in high yield. In the presence of bromotrichloromethane or iodoform, bromides and iodides are formed in yields > 80 %. This reaction can be successfully applied to primary, secondary, or tertiary esters and offers an interesting variant to the usual Hunsdiecker procedure. 

The procedure given here is essentially that described previously by the submitters. -Chlorophenyl isothiocyanate has been prepared from sym-di-p-chloiophenyl thiourea with iodine in alcoholic solution, from ammonium p-chlorophenyldithio-carbamate and lead nitrate [cf. also Org. Syntheses, Coll. Vol. 1 447 (1932)], by the action of thiophosgene on />-chloroaniline and from -chloroaniline with thiocarbonyl tetrachloride in the presence of stannous chloride. ... 

Uses Coolant and refrigerant herbicide and fumigant organic synthesis-methylating agent manufacturing of silicone polymers, pharmaceuticals, tetramethyl lead, synthetic rubber, methyl cellulose, agricultural chemicals and nonflammable films preparation of methylene chloride, carbon tetrachloride, chloroform low temperature solvent and extractant catalytic carrier for butyl rubber polymerization topical anesthetic fluid for thermometric and thermostatic equipment. 

When no electrophile is present, reduction of carbon tetrachloride leads to di-chlorocarbene by elimination of chloride ion from the trichloromethyl carbanion intermediate. Dichloromethane is the best solvent for this process [79], The car-bene is trapped by reaction with an alkene to form a dichlorocyclopropane (Table... 

The preferred preparation method is to introduce chlorine into the solution while dissolving lead dioxide in cold concentrated HCl. This prevents decomposition of PbCL to PbCb and enhances the formation of chloroplumbic acid, H2PbCl6 in solution. Addition of ammonium chloride precipitates out yellow ammonium chloroplumbate, (NH4)2PbCl6, which is filtered out. The yellow precipitate, on treatment with cold concentrated sulfuric acid, forms lead tetrachloride, which separates out as a yellow oily liquid. The reactions are ... 

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