Residue organotin

Conversion of the organotin chlorides into fluorides, bromides, or iodides is usually carried out with the sodium halide in acetone, and residual organotin compounds are often removed as the insoluble organotin fluorides. The fluorides can then be converted back into the bromides, chlorides, or iodides (and exchanges by other halides can be brought about with aqueous ammonium halides at room temperature).332 A 2 1 mixture (solid solution) of CsF and CsOH, mixed with silica gel, also provides a very convenient way of removing organotin halide byproducts from solution.333... 

Removal of organotin residues. Organotin reagents often cause operational difficulties in that clean removal of their residue is problematical. Brief treatment of the crude reaction mixture with NaBH.CN (reduction to RjSnH) facilitates purification. ... 

The advantages claimed for organotin polymer-based antifouling paints include constant toxicant deHvery vs time, erosion rate and toxicant deHvery are controUable, no depleted paint residue to remove and dispose, 100% utilization of toxicant, polishing at high erosion rates, surface is self-cleaning, and function is continuously reactivated. 

Although inhibitors are deliberately added to the silicone formulation to control cure rate, unwanted cure inhibition can be caused by other species that react to form strong complexes with the platinum catalyst. Most notable of these undesired inhibitors include organotin and other organometallic compounds, sulfur, polysulfides, polysulfones or other sulfur-containing materials, amines, urethanes or amine-containing materials, unsaturated hydrocarbons in plasticizers, and some solder flux residues. 

The versatility, predictability and functional-group tolerance of free radical methodology has led to the gradual emergence of homolytic reactions in the armory of synthetic chemistry. Tin hydrides have been successfully employed in radical chemistry for the last 40 years however, there are drawbacks associated with tin-based chemistry. Organotin residues are notoriously difficult to remove from desired end products, and this, coupled with the fact that many organotin compounds are neurotoxins, makes techniques using tin inappro-... 

The introduction of organotin residues into an epoxide resin is known to improve the dielectric properties and thermal stability of hardened compositions 71). 

It is likely that cross-linking of an organic copolymer proceeds through a stage of excitation and photochemical conversion of photosensitive side-chain organotin fragments containing coordination-bound residues. 

Organotin Algae Initial cone. (pgr1) Tin in algae (Egg-1) Residue in supernatant ( g l-1) BCF (xlO5)... 

Kumpulainen, J. and P. Koivistoinen. 1977. Advances in tin compound analysis with special reference to organotin pesticide residues. Residue Rev. 66 1-18. 

Tin-based reagents are not always snitable owing to the toxicity of organotin derivatives and the difficulties often encountered in removing tin residues from the final product. Therefore, the same authors have carried out additional experiments with 17d and several different alkyl halides under tin-free conditions. The treatment of 16d with tert-butyldiphenylsilyl chloride (TBDPSCl) and triethylamine in the presence of silver triflate in CH2CI2 affords the bis(silyloxy)enamine 17d in 92% yield (Scheme 17). When the radical reaction was carried out with ethyl iodoacetate in the presence of 2,2 -azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) as the initiator in CH2CI2, the oxime ether 19 was obtained in 83% yield (Scheme 17). 

Lately, a number of papers have dealt with microwave-assisted reactions on palladium-doped A1203. Villemin reported on Stifle, Suzuki, Heck and Trost—Tsuji reactions where potassium fluoride on alumina was used as the base26. The reactions were carried out without solvent or stabilising phosphine ligands in single-mode reactors. The Stifle reactions were noteworthy as the toxic organotin residue remained adsorbed on the solid support, thus allowing a simplified work-up procedure for the otherwise unpleasant, and toxic, stannous by-products. Both the Stifle and the Suzuki reactions could be performed under air. Furthermore, it was noted that with experiments where the... 

Gauer et al. [4] described a gas chromatographic method for the determination of the residues of tricyclohexylhydroxystannane and its dicyclohexyl metabolite on strawberries, apples and grapes that have been treated with Pictran miticide. Crop samples were treated with aqueous hydrobromic acid to form bromo derivatives of the organotin compounds, and these derivatives were extracted into benzene. When the residue levels were less than 1 pg/1, the... 

Total organic tin compounds in house dust mostly amount to some milligrams per kilogram, but they might form residues of some hundred mg kg"1 as well (Greenpeace Nederland 2001). Concentrations of organotins in indoor air have not yet been published. 

Corbin HB. 1970. Separation and determination of trace amounts of tin present as organotin residues on fruits. J Assoc Off Anal Chem 53 140-146. 

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