Compounds of Tin

Of the large volume of tin compounds reported in the Hterature, possibly only ca 100 are commercially important. The most commercially significant inorganic compounds include stannic chloride, stannic oxide, potassium staimate, sodium staimate, staimous chloride, stannous fluoride, stannous fluoroborate, stannous oxide, stannous pyrophosphate, stannous sulfate, stannous 2-ethyUiexanoate, and stannous oxalate. Also important are organotins of the dimethyl tin, dibutyltin, tributyltin, dioctyltin, triphenyl tin, and tricyclohexyltin families. 

Other specialized uses of Sn and its alloys are as type metal, as the molten-metal bath in the manufacture of float glass and as the alloy NbsSn in superconducting magnets. The many industrial and domestic uses of tin compounds are discussed in later sections these compounds account for about 15% of the tin produced worldwide. 

Wong PTS, Chau YK, Kramar O, Bengert GA (1982) Structure-toxicity relationship of tin compounds on algae. Canadian Journal of Fisheries and Aquatic Sciences, 39 483-488. 

C09-0020. Tin tetrachloride (S11CI4) is an important starting material for the preparation of a variety of tin compounds. Build the Lewis structure for SnCl4 and determine its shape. 

Haslam et al. [32] reported the determination of Al in polyolefins by AAS. Typical AAS tests on rubber compounds involve several steps. The sample is combusted, and the resulting ash is dissolved in distilled de-ionised water. The solution is then used for AAS [126]. AAS or EDS can also be used for element analysis of filler particles. In order to determine the uniformity of tin compounds in polychloroprene after milling and pressing, Hornsby et al. [127] have ashed various pieces from one composition. After fusion of the residue with sodium peroxide and dissolution in HC1, the Sn content was determined by means of AAS. Typical industrial AAS measurements concern the determination of Ca in Ca stearate, Zn in Zn stearate, Ca- and Zn stearate in PE, Ca and Ti in PE film or Al and V in rubbers. 

Fractional separation of tin compounds used as stabilisers in PVC was based on substoichiometric isotope dilution analysis [446]. The tin compounds were isolated by extraction and complexed with salicylideneamino-2-thiophenol, followed by controlled addition of y-irradiated tributyl tin oxide and measurement of the y-activity. PVC containing a nominal 0.63% (Bu Sn analysed 0.614 0.016% in nine determinations. 

Stoichiometric use of a tin reagent to prepare the phenylacetone 4 Toxicity of tin compounds, and operational inefficiency based on high molecular weight of reagent and excessive chromatography required to reject tin residues... 

Some of the disadvantages of the Stille reaction, e. g. the low reactivity of some substrates, separation difficulties in chromatography, and the toxicity of tin compounds, have been ameliorated by recent efforts to improve the procedure. Curran has, in a series of papers, reported the development of the concept of fluorous chemistry, in which the special solubility properties of perfluorinated or partly fluorinated reagents and solvents are put to good use [45]. In short, fluorinated solvents are well known for their insolubility in standard organic solvents or water. If a compound contains a sufficient number of fluorine atoms it will partition to the fluorous phase, if such a phase is present. An extraction procedure would thus give rise to a three-phase solution enabling ready separation of fluorinated from nonfluorinated compounds. 

Figure 5. Effect of tin compounds on oxygen index vs. temperature of ethylene-acrylic rubber containing 50% ATH. Key 0, 2.5% ZnSn(OH)6 , 2.5% Sn02 O. no tin.

The purpose of this paper is to briefly review recent research into the effectiveness and mode of action of tin compounds as fire retardants in a number of halogenated and halogen-free, plastic and elastomeric substrates. 

S. Patai (Ed.), The Chemistry of Functional Groups, Supplement A The Chemistry of Double-bonded Functional Groups, Vol.2. (esp. pp.1-52) Wiley, Chichester, 1989 F. Hartley and S. Patai (Eds.), The Chemistry of the Metal-carbon Bond, Wiley, Chichester, 1982 P. A. Cusack, P. J. Smith, J. D. Donaldson and S. M. Grimes, A Bibliography of X-Ray Crystal Structures of Tin Compounds, International Tin Research Institute Publication 588, 1981 Organotin Cluster Chemistry, R. R. Holmes, Acct. Chem. Research, 22, 190 (1989). 

A method for the preparation of dendritic Sn by the electrolysis of alkyltin complexes has been described. Bu2SnBr2 and BusSnBr form as intermediates143. The method is aimed at recovery of elemental tin from residues of tin compounds and for reuse in the preparation of tin halides. 

II. THE METHYLATION OF TIN COMPOUNDS UNDER ENVIRONMENTAL OR MODEL ENVIRONMENTAL CONDITIONS... 

Generally, tin compounds of 3-4 mgday-1 are ingested in the human body, and are absorbed poorly from the digestive tracts. 40% of the tin are excreted via urine and feces. Tin compounds tend to accumulate in liver, kidney and bone. By the oral route, high levels of tin compounds cause gastrointestinal symptoms such as nausea, vomiting and abdominal pain and headache. 

Table 8.11 Effects of Tin Compounds on Selected Species of Mammals... 

Strecker reactions provide one of the most efficient methods for the synthesis of a-amino nitriles, which are useful intermediates in the synthesis of amino acids and nitrogen-containing heterocycles. Although classical Strecker reactions have some limitations, use of trimethylsilyl cyanide (TMSCN) as a cyano anion source provides promising and safer routes to these compounds.133-351 Consequently, we focused our attention on tributyltin cyanide (Bu3SnCN), because Bu3SnCN is stable in water and is also a potential cyano anion source. Indeed, the Strecker-type reactions of aldehydes, amines, and Bu3SnCN proceeded smoothly in water (Eq. 9).1361 It should be noted that no surfactants are required in this reaction. Furthermore, Complete recovery of the toxic tin compounds is also possible in the form of bis(tributyltin) oxide after the reaction is over. Since conversion of bis(tributyltin) oxide to tributyltin cyanide is known in the literature, this procedure provides a solution to the problem associated with toxicity of tin compounds. 

Chau, Y.K. (1980) Biological methylation of tin compounds in the aquatic environment. 3rd International Conference Organometal Coordinating Chem. Germanium, Tin, Lead, July 1980, University of Dortmund, West Germany. 

Tin is thought to be an essential trace element for some species, although its precise role remains unknown. Some therapeutic uses of tin compounds have been proposed, and triorganotin carboxylates are effective bacteriocides and pesticides. Tin is, of course, an important component of a number of alloys, with copper in bronze (the Bronze age began about 3500 BC), and with lead in pewter. 

With the sign of AR/R established, the structure and bonding of tin compounds can be investigated. From the scatter plot in Figure 1, the Sn compounds fall to the left of white tin, while the Sn compounds fall to the right. The organotin compounds are clustered in the cross-... 

Example In mass spectra of tin compounds, the Sn isotopic peak could easily be overseen or simply be superimposed by background signals (Fig. 3.7). Here, one should identify the °Sn peak from its unique position within the characteristic pattern before stepping through the spectrum from peak to peak. For all other elements contained in the respective ions still the lowest mass isotope would be used in calculations. 

Schwartz, K., Milne, D.B. and Vinyard, E. (1970). Growth elfects of tin compounds in rats maintained in a trace element-controlled environment, Biochem. Biophys. Res. Comm., 40, 22-29. 

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