Acids Tin chloride

Samples are digested with a mixture of nitric and sulfuric acids. Tin chloride is then added to reduce arsenic in the digestate to the trivalent form (As3+) and selenium to the tetravalent form (Se4+). The metals are converted into volatile arsenic hydride and... 

However, the generation of thin palladium membranes onto ceramic surfaces is more complicated. Methods such as spray pyrolysis (see also Section 4.1.3), chemical vapour deposition and sputtering are used. Another method commonly applied [400] is electroless plating [408]. Palladium particles are produced from palladium solution containing amine complexes of palladium in the presence of reducing agents. Palladium nuclei need to be seeded onto the surface prior to the coating procedure [408]. Ceramic surfaces such as a-alumina are first sensitised in acidic tin chloride and then palladium is seeded from acidic palladium ammonia chloride [408]. 

Sulfuric acid, 80% Sulfuric acid, 93% Sulfuric acid, over 93% Sulfuric acid, Fuming Sulfurous acid Tannic acid Tortoric acid Tin Chloride Tin Sulfate Toluene... 

CONH2 -CONH- Amides (nylon) Phosphotungstic acid Tin chloride... 

In presence of hydrochloric acid, tin(II) in aqueous solution (1) is precipitated by hydrogen sulphide as brown SnS, and (2) will reduce mercury(II) chloride first to mercury(I) chloride (white precipitate) and then to metallic mercury. 

Ethylene oxide Acids and bases, alcohols, air, 1,3-nitroaniline, aluminum chloride, aluminum oxide, ammonia, copper, iron chlorides and oxides, magnesium perchlorate, mercaptans, potassium, tin chlorides, alkane thiols... 

Preparation. Thiophosgene forms from the reaction of carbon tetrachloride with hydrogen sulfide, sulfur, or various sulfides at elevated temperatures. Of more preparative value is the reduction of trichi oromethanesulfenyl chloride [594-42-3] by various reducing agents, eg, tin and hydrochloric acid, staimous chloride, iron and acetic acid, phosphoms, copper, sulfur dioxide with iodine catalyst, or hydrogen sulfide over charcoal or sihca gel catalyst (42,43). 

Mercaptides are unchallenged as the ligand of choice for the other entities bonded to the tin, but carboxylates can also be used. Whereas a variety of mercaptans are used, the thioglycolic acid derivatives remain the largest single mercaptan. Dibutyltin bis(isooctyl thioglycolate) [25168-24-5] and butyltin tris(isooctyl thioglycolate) [25852-70A] are two common examples. These materials are produced by the reaction of the appropriate alkyl tin chloride or oxide, and the mercaptan. 

The production of triphenyl tin hydroxide [76-87-9] and triphenyl tin acetate [900-95-8] start with triphenyl tin chloride, which is prepared by the Kocheshkov redistribution reaction from tetraphenyltin and tin tetrachloride. The hydroxide is prepared from the chloride by hydrolysis with aqueous sodium hydroxide. The acetate can be made directiy from the chloride using sodium acetate or from the hydroxide by neutrali2ation with a stoichiometric quantity of acetic acid. 

Catalysts for dielectric surfaces are more complex than the simple salts used on metals. The original catalysts were separate solutions of acidic staimous chloride [7772-99-8J, used to wet the surface and deposit an adherent reducing agent, and acidic palladium chloride [7647-10-17, which was reduced to metallic palladium by the tin. This two-step catalyst system is now essentially obsolete. One-step catalysts consist of a stabilized, pre-reacted solution of the palladium and staimous chlorides. The one-step catalyst is more stable, more active, and more economical than the two-step catalyst (21,23). A separate acceleration or activation solution removes loose palladium and excess tin before the catalyzed part is placed in the electroless bath, prolonging bath life and stability. 

The reaction is cataly2ed by all but the weakest acids. In the dehydration of ethanol over heterogeneous catalysts, such as alumina (342—346), ether is the main product below 260°C at higher temperatures both ether and ethylene are produced. Other catalysts used include siUca—alumina (347,348), copper sulfate, tin chloride, manganous chloride, aluminum chloride, chrome alum, and chromium sulfate (349,350). 

Resoles are usually those phenolics made under alkaline conditions with an excess of aldehyde. The name denotes a phenol alcohol, which is the dominant species in most resoles. The most common catalyst is sodium hydroxide, though lithium, potassium, magnesium, calcium, strontium, and barium hydroxides or oxides are also frequently used. Amine catalysis is also common. Occasionally, a Lewis acid salt, such as zinc acetate or tin chloride will be used to achieve some special property. Due to inclusion of excess aldehyde, resoles are capable of curing without addition of methylene donors. Although cure accelerators are available, it is common to cure resoles by application of heat alone. 

In the synthesis of carpamic acid (98), Mitsutaka and Ogawa have used 1,2-dihydropyridine as a starting material [80H(14)169]. Photooxygenation of dihydropyridine 8h afforded enr/o-peroxide 96. Subsequent stereoselective nucleophilic reaction of 96 with ethyl vinyl ether in the presence of tin chloride gave tetrahydropyridinol 97, which was then converted into carpamic acid (98) in six more steps. 

The cymidiu sulphouic acid is then diazotised in the usual manner by treating with sodium nitrite in acid solution and the diazo body reduced with alkaline tin chloride solution, or with formic acid and powdered copper, or with other relatively gentle reducing agents. The 3 or 5 cymidin sulphonic acid gives by the above process one and the same cymene sulphonic acid, viz., l-methyl-3-sulphonic-4-isopropyl benzene. 

Chlor-wasserstoffsaure, /. hydrochloric acid, -wismut, n. bismuth (tri)chloride. -zink, n. zinc chloride, -zinn, n. tin chloride. 

Zinn-bromwasserstoffsaure, /. bromostannic acid, -butter, /. (Old Chem.) butter of tin (stannic chloride), -charge, /. (Textiles) tin weighting, -chlorammonium, n. ammonium chlorostannate, (Dyeing) pink salt, -chlorid, n. tin chloride, specif, stannic chloride, tin (IV) chloride, -chloriir, n. stannous chloride, tin(II) chloride. 

Nitropropane Nitrosyl fluoride Nitrosyl perchlorate Nitrourea Nitrous acid Nitryl chloride Oxalic acid See under Nitromethane chlorosulfonic acid, oleum Haloalkenes, metals, nonmetals Acetones, amines, diethyl ether, metal salts, organic materials Mercury(II) and silver salts Phosphine, phosphorus trichloride, silver nitrate, semicarbazone Ammonia, sulfur trioxide, tin(IV) bromide and iodide Furfuryl alcohol, silver, mercury, sodium chlorate, sodium chlorite, sodium hypochlorite... 

Nitroaromatic compounds cire useful in synthesis because converting the nitro (-NO2) group to an cimino (-NH2) group is relatively easy. For example, the reaction of nitrobenzene with acidic tin(II) chloride (SnCl2) converts nitrobenzene to aniline, an important industrial chemical used in the production of medicines, plastics, and dyes, to name but a few. 

Nitration with concentrated nitric acid in acetic anhydride and glacial acetic acid affords a mixture of 2- and 3-nitrothiophenes (in the ratio 6 1) (Scheme 6.33). However, bromination with bromine in diethyl ether and 48% hydrobromic acid, starting at -25 °C and allowing the reaction temperature to rise to -5 °C, gives 2-bromothiophene. If the experiment is initiated at -10 °C and the temperature is then allowed to rise to + 10 °C, 2,5-dibromothiophene is formed. 2,3,5-Tribromination occurs in 48% hydrobromic acid, starting the experiment at room temperature and allowing the temperature to rise to 75 °C. Acetylation with acetyl chloride in the presence of the Lewis acid tin(IV) chloride gives 2-acetylthiophene, and efficient 2-formylation takes place under Vilsmeier conditions (see Section 6.1.2). 

Activation of the hydroxyl group as an acetate leaving group to promote oxazoline formation has been applied extensively in carbohydrates to afford p-glycosylation with high selectivity. A Lewis acid such as ferric chloride (FeCL), tin chloride (SnCLt), or TMSOTf is usually added to facilitate cyclization. Several recent examples are shown in Scheme 8.20. Compound 54 has been further elaborated to 1,2-dideoxynojmmycin 54a, a potent p-Al-acetylglycosamine inhibitor. 

In order to shorten the reaction time, various heavy metal salts (zinc, lead, and manganese acetates) of weak organic acids, zinc or cobalt and tin chlorides are added to the reaction mixture [11]. For example, refluxing an uncatalyzed mixture of 3 moles of isobutyl alcohol and urea for 150 hr at 108°-126°C gives a 49% yield of the carbamate. Adding lead acetate or cobalt chloride to the same reaction lowers the reaction time to 75 hr, at which point an 88-92 % yield is obtained. In another example, ethylene glycol (1 mole) and urea (2 moles) are heated for 3 hr at 135°-155°C with Mn(OAc)2 to give a 78% yield of the diurethane [11]. The commercial production of butyl carbamate uses catalytic quantities of cupric acetate [12]. 

Tin(II) and Tm(IV) Hydroxides. Prepare tin (I I) and tin(IV) hydroxides in separate test tubes from solutions of tin chlorides. What reagent should be used to precipitate the tin hydroxides Do tin hydroxides exhibit amphoteric properties What tin compounds are known as a- and P-stannic acids How are they prepared Write the equations of the reactions. 

Preparation of Chlorostannic Acid. Pour concentrated hydrochloric acid into tin(IV) chloride in a proportion of 28 parts by mass of hydrogen choride to 100 parts by mass of the tin chloride. Cool the solution and pass a stream of dry hydrogen chloride into it until its absorption stops. Test the reaction of chlorostannic acid with... 

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