Lead salts tetrachloride

Even though the preparation of tetraisocyanatosilane has been previously described in Inorganic Syntheses, there exists a less time-consuming and far less expensive patented procedure that has been largely overlooked. This procedure involves the reaction of silicon tetrachloride with sodium or potassium cyanate in place of the silver or lead salt, which first must be freshly prepared. The use of liquid sulfur dioxide as the solvent, instead of benzene, offers no real increase in handling problems. The details of this alternate method adapted to a laboratory... 

The precipitation also occurs from solutions containing alkali tartrate or cyanide. The lead salt is soluble in carbon tetrachloride and many other organic liquids. Consequently, the green solution of dithizone in carbon tetrachloride becomes deep red when it is shaken with a water solution of a lead salt. 

Procedure. A drop of a saturated aqueous solution of EDTA is added to a drop of the test solution in a micro test tube and the mixture shaken with a few drops of a solution of dithizone in chloroform or carbon tetrachloride (see page 000). The green color of the reagent solution becomes yellow-orange when dialkyl-lead salts are present. Trialkyl-lead salts form a red-orange complex with dithizone. 

Although direct nitration was not possible, 2-amino-4-methylselena-zole can be directly brominated by treatment with bromine in carbon tetrachloride, the hydrogen bromide salt of 2-amino-4-methyl-5-bromoselenazole, mp 180°C (decomp.) is formed. However, all attempts to obtain the free base from this salt failed and led to complete decomposition. In this bromination, an equivalent quantity of bromine must be used excess also leads to complete destruction of the molecule. From the decomposition products an oily compound can be detected similar to bromoacetone. ... 

Two routes for the reaction of substrate with the triphenylphosphine-carbon tetrachloride reagent are now recognized.61 62>64 Direct interaction (76) of the substrate with the initially formed dipolar associate leads to the formation of chloroform and the intermediate phosphonium salt (77). 

Other reported syntheses include the Reimer-Tiemann reaction, in which carbon tetrachloride is condensed with phenol in the presence of potassium hydroxide. A mixture of the ortho- and para-isomers is obtained the para-isomer predominates. -Hydroxybenzoic acid can be synthesized from phenol, carbon monoxide, and an alkali carbonate (52). It can also be obtained by heating alkali salts of -cresol at high temperatures (260—270°C) over metallic oxides, eg, lead dioxide, manganese dioxide, iron oxide, or copper oxide, or with mixed alkali and a copper catalyst (53). Heating potassium salicylate at 240°C for 1—1.5 h results in a 70—80% yield of -hydroxybenzoic acid (54). When the dipotassium salt of salicylic acid is heated in an atmosphere of carbon dioxide, an almost complete conversion to -hydroxybenzoic acid results. They>-aminobenzoic acid can be converted to the diazo acid with nitrous acid followed by hydrolysis. Finally, the sulfo- and halogenobenzoic acids can be fused with alkali. 

Synonym Neatsfoot Oil Necatorina Nechexane Neutral Ahhonium Pluoride Neutral Anhydrous Calcium Hypochlorite Neutral Lead Acetate Neutral Nicotine Sulfate Neutral Potassium Chromate Neutral Sodium Chromatetanhydrous Neutral Verdigris Nickel Acetate Nickel Acetate Tetrahyorate Nickel Ammonium Sulfate Nickel Ammonium Sulfate Hexahydrate Nickel Bromide Nickel Bromide Trihydrate Nickel Carbonyl Nickel Chloride Nickel Chloride Nickel Cyanide Nickel Iiu Fluoborate Nickel Fluoroborate Solution Nickel Fluoroborate Nickel Formate Nickel Formate Dihyorate Nickel Nitrate Nickel Nitrate Hexahydrate Nickel Sulfate Nickel Tetracarbokyl Nickelous Acetate Nickelous Sulfate Nicotine Nicotine Sulfate Nifos Nitralin Nitram O-Nitraniline P-Nitraniline Nitric Acid Nitric Acid, Aluminum Salt Nitric Acid, Iron (111) Salt Compound Name Oil Neatsfoot Carbon Tetrachloride Neohexane Ammonium Fluoride Calcium Hypochlorite Lead Acetate Nicotine Sulfate Potassium Chromate Sodium Chromate Copper Acetate Nickel Acetate Nickel Acetate Nickel Ammonium Sulfate Nickel Ammonium Sulfate Nickel Bromide Nickel Bromide Nickel Carbonyl Nickel Chloride Nickel Chloride Nickel Cyanide Nickel Fluoroborate Nickel Fluoroborate Nickel Fluoroborate Nickel Formate Nickel Formate Nickel Nitrate Nickel Nitrate Nickel Sulfate Nickel Carbonyl Nickel Acetate Nickel Sulfate Nicotine Nicotine Sulfate Tetraethyl Pyrophosphate Nitralin Ammonium Nitrate 2-Nitroaniline 4-Nitroaniline Nitric Acid Aluminum Nitrate Ferric Nitrate... 

Lead Tetrachloride, 2CH 3.C6H4.N2C + PfcCl4 yel crysts, mp - explodes at 78-80° stable if kept dry and in absence of air was prepd by treating the chloride salt with lead tetrachloride... 

A repetition of the foregoing work by Meyer and Pawletta,4 however, failed to confirm the production of selenium trioxide. According to these investigators, the dissolution of selenium in selenium oxychloride results in the formation of selenious chloride, and the precipitate obtained by the action of ozone is a mixture of this salt with selenium dioxide. Furthermore, substitution of carbon tetrachloride or glacial acetic acid for selenium oxychloride did not lead to the separation of the tri oxide. 

The yellow solution contains lead tetrachloride. It is puzzling to explain why lead dioxide will not react with two of the strong acids tried, yet does react with hydrochloric acid to give what is apparently a salt, PbCl4. The explanation lies in the character of lead tetrachloride, which is practically un-ionized, and therefore is hardly to be classed as a salt. In the anhydrous condition it is a liquid like carbon tetrachloride. Furthermore it combines with excess HC1 to form the complex acid H2PbCl6, of which the ammonium salt (NH4)2PbCl6 can be crystallized. By comparison, if nitric acid reacted with lead dioxide, the tetranitrate, Pb (NO3)4, would be the product this presumably would be highly ionized like all nitrates, which means that it would have to hydrolyze completely. 

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