Organotin compounds,

Organotin hydroxides tend to self-organize by formation of dative O — Sn bonds, and so their supramolecular architectures are completely different. Unlike silicon or germanium, tin has a strong tendency to increase its coordination number, which will also influence the structures of Sn OH organo derivatives. 

The stepwise hydrolysis of monoorganotin trihalides can lead to a great variety of compounds. The dative bond hydrated dimers [RSn(0H)X2-H20]2, 20, formed in the first step, containing six-coordinate tin, are associated via intermolecular hydrogen-bonds established between the OH bridges and the halogen atoms. 

The hydrogen-bonds connect the centrosymmetric dimers into chains, which in turn are associated into two-dimensional layers. Several such compounds have been structurally investigated, with R = Et [49], Bu [50], PE, and Bu [51]. 

Another example is bis(trimethyltin)dimesylamide hydroxide, 22, which contains antiparallel chains connected by 0-H- -N bonds to form a ladder structure [55]. 

Hydrogen-bond bridges between coordinated water molecules and oxygen atoms from the sulfonic group lead to self-assembly of trimethyltin benzenesulfonate molecules into a supramolecular chain-like array, 25 [58], 

The tetraorganotin compounds 502 and 503 react with chlorosulfonic acid (one equivalent) in carbon tetrachloride at -10 °C with facile specific cleavage of the tin-carbon bonds. In the dialkyl diaryltins, e.g. 503, the tin-aryl carbon bonds are preferentially cleaved. Chlorosulfonic acid at low temperature (-10 °C) cleaves one tin-butyl bond from tetrabutyltin and two tin-aryl bonds from both tetraaryltin and dibutyldiaryltin 503. The reactions provide a possible one-step synthetic route to the organotin sulfonate esters 504 and 505 respectively. 

R4Sn Bu2SnAr2 RnSn(S03R)4 f, Bu2Sn(S03Ar)2 

For the preparation of organotin compounds the procedure most widely applicable and that most often used in. the laboratory is to treat tin tetra- 

For synthesis of certain organotin compounds the Grignard reagent is often replaced by an organolithium compound.394,395 

The reaction of a tin tetrahalide with a Grignard reagent or an organolithium compound has been used also for synthesis of the following compounds SnR4 R = cycloalkyl, alkenyl, or alkynyl, e.g., cyclopropyl,396 vinyl,397,398 trifluorovinyl,399 cis- and ms-propenyl,400 (cyclohexylethynyl) 281 substituted and unsubstituted (phenylethynyl) 282,401 ring-substituted aryl of very various types, e.g., w-(trifluoromethyl)phenyl, p-fluorophenyl,402 and pentafluor ophenyl.2 7 8 

Such tetrasubstituted stannanes can then be readily converted into organic tin halides by a Kozeschkow disproportionation, thus 403 

Organotin compounds of this type can be further treated with Grignard reagents or organo-lithium or -sodium compounds, thus yielding a variety of mixed organotin derivatives for example, trialkyl- and tri(cyclohexyl)-tin 

The isolation and determination of organotin compounds in vinegar and salad oil after contact with stabilised hard PVC foil has also been studied by Wieczorek [41]. Foil samples were extracted under reflux, with pentane or ethyl ether other samples were left in contact with oil or vinegar for periods up to 11 months. The organotin compounds in the solvent extracts or in the oil (diluted with pentane) or a chloroform extract of the vinegar were then adsorbed on to a column of Florisil (which was then washed with hexane and ether, if necessary, to remove the oil), eluted with chloroform 

Adcock and Hope [43] developed a spectrometric method based on catechol violet for the determination of dioctyltin 5,5 bis(isooctylmercaptoacetate) as tin in vinegar and olive oil. 

A method has been described for determining the migration of organotin stabilisers such as bis(2-ethylhexyloxycarbonyl)methylthiodioctyltin from, PVC bottles into beer. After storage of beer for 8 weeks at 20 °C in bottles stabilised with 1.13% of bis(2-ethylhexyloxycarbonyl)methylthiodioctyltin, it was treated with sulfuric acid 

The tin was also determined by measurement of radioactivity after storage of beer in bottles stabilised with (C-labelled bis [(2-ethylhexyloxycarbonyl) methylthio]dioctyltin. Only 1.7 pg of tin per litre was found - the FDA limit being 1 mg per litre. 

By reduction of the scope of the investigation to the non-polar (in general more toxic) organotins and accepting a relative high detection limit, a simple robust method can be used. If the concentration is high enough, the extraction can be followed by a relatively simple measurement. Compano etal. (1995) described an extraction with methanol for triphenyltin and tributyltin followed by HPLC-separation, post-column derivatisation and fluorimetric detection. 

For measuring at low concentrations, the derivatisation of the extracted organotin compound with sodium tetraethylborate is an established procedure to make a more sensitive gas chromatographic analysis possible. Derivatisation can be combined with the extraction as prescribed in the German method but can also be carried out after the extraction. Selective detection is possible using GC-MS. For organo-metallic compounds atomic emission or atomic absorption detection is not only very sensitive, but very selective. The steps necessary for the chromatographic separation and detection are described in ISO/CD 17353 (2001). Application of this well-described method for soil samples does not mean that the difficulties with the extraction have been overcome. 

As shown in this sub-chapter, the developments in the analysis of all the organotin compounds in soil has not led to a well established and general accepted analytical method. This is because the target compounds differ too much in polarity. Reducing the scope of the analytical method decreases the necessary steps of the analytical procedure, resulting in a more robust system The most reliable and robust method will be obtained when the analytical scope has been reduced to a selection (based on the properties of the organotin compounds). More research is necessary for the development of a method with a broad scope. 

For the reduction of sulfides and selenides to free radicals and subsequent cyclization onto alkynes, see page 413, Section 2.3. 

Aryl halides react with a wide variety of aryl-, alkenyl- and alkylstan-nanes[548-550]. Coupling of an aryl tritlate with an arylstannane is a good preparative method for diaryls such as 688. The coupling of alkenylstannanes with alkenyl halides proceeds stereospecifically to give conjugated dienes 689. The allylstannane 690 is used for allylation[397,546,551-553]. Aryl and enol triflates react with organostannanes smoothly in the presence of LiCl[554]. 

The cross-coupling of aromatic and heteroaromatic rings has been carried out extensively[555]. Tin compounds of heterocycles such as oxazo-lines[556,557], thiophene[558,559], furans[558], pyridines[558], and seleno-phenes [560] can be coupled with aryl halides. The syntheses of the phenylo.xazoline 691[552], dithiophenopyridine 692[56l] and 3-(2-pyridyl)qui-noline 693[562] are typical examples. 

Arenediazonium salts are also used for the couplina[563], (Z)-Stilbene was obtained unexpectedly by the reaction of the ti-stannylstyrene 694 by addition-elimination. This is a good preparative method for cu-stilbene[564]. The rather inactive aryl chloride 695 can be used for coupling with organostannanes by the coordination of Cr(CO)3 on aromatic rings[3.565]. 

The coupling of the enol triflate 703 with the vinylstannane 704[397] has been applied to the synthesis of glycinoeclepin[576]. The introduction of a (Z)-propenyl group in the / -lactam derivative 705 proceeds by use of tri-2-furylphosphine[577]. However, later a smooth reaction to give the propenyl-iactam in 82% yield was achieved simply by treating with Pd(OAc)2 in NMP or CH2CI2 for 3-5 min without addition of LiCI and the phosphine ligand[578]. 

The intramolecular coupling of organostannanes is applied to macrolide synthesis. In the zearalenone synthesis, no cyclization was observed between arylstannane and alkenyl iodide. However, intramolecular coupling take.s place between the alkenylstannane and aryl iodide in 706. A similar cyclization is possible by the reaction of the alkenylstannane 707 with enol triflate[579]. The coupling was applied to the preparation of the bicyclic 1,3-diene system 708[580]. 

SePh SePh (PhSe)2, hv For X and/or Y equals halogen, see page 655, Section 4. JOC 56 5721 (1991) 

Pesticide Fish (Various Species) LC50 (24-96 h) (mg/1) Daphnia EC50 (48 h) (mg/1) Rodents (Various Species or Sex) Oral LD50 (mg/kg) 

Note LC50 = lethal concentration in 50% of the population EC50 = effective concentration in 50% of the population. 

Source Data from Tomlin, C., Ed. 2000. The Pesticide Manual A World Compendium. British Crop Protection Council, Farnham, Surrey. 1250 pp. 

Tributyltin and tributyltin oxide are still used on boats and ships to prevent growth of barnacles. They are extremely toxic for many invertebrates in the sea, notably some snails whose sexual organs develop abnormally. In these snails the female develops a penis. In oysters and other bivalves, their shells become too thick. Tributyltin must be regarded as one of the most serious environmental pollutants, but contrary to the lower analogues, trimethyl tin and triethyltin, they are not very toxic to man and other mammals. Trimethyltin is of considerable interest for neurotoxicologists because it leads specifically to atrophy of the center for short-term memory, the hippocampus. The ethyl analogue has other serious detrimental effects on the brain. 

Source Reproduced by permission from the Royal Society of Chemistry, London [246] 

Mixtures of RjSn compounds (R = n-butyl, phenyl, cyclohexyl) were separated by ion exchange-high performance liquid chromatography-graphite furnace atomic absorption spectrometry [252]. The small spread in calibration slopes in Fig. 4.10 signifies similar efficiencies for their separation and column recovery, as well as graphite furnace sensitivities. 

Source Reproduced by permission from Kluwer Academic, Plenum Amsterdam [251] 

Nygren et al. [260] interfaced on-line a liquid chromatograph to a continuously heated graphite furnace atomic absorption spectrometer to determine di- and tributyltin species in non saline waters with a detection limit of 0.5pg tin absolute. 

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Organotin compounds such as aryl-, alkenyl-, and alkynylstannanes are useful for the ketone synthesis by transmetallation of acylpalladium 529 and reductive elimination of 530 as shown[389-393]. Acetophenone (531) is obtained by the carbonylation of iodobenzene with Me4Sn. Diaryl ketones... 

E. A. Boettner, G. L. Bah, Z. Hollingsworth, and R. Aquiao, Organic and Organotin Compounds Peachedfrom PWC and CPWC Pipes, U.S. Environmental Protection Agency Report, EPA-600/1-81-062, Washiagton, D.C., 1981. 

The reaction is of practical importance in the vulcanization of siUcone mbbers (see Rubber compounding). Linear hydroxy-terrninated polydimethyl siloxanes are conveniently cross-linked by reaction with methyldiethoxysilane or triethoxysilane [998-30-1]. Catalysts are amines, carboxyflc acid salts of divalent metals such as Zn, Sn, Pb, Fe, Ba, and Ca, and organotin compounds. Hydroxy-terrninated polysiloxanes react with Si—H-containing polysiloxanes to... 

Tin, having valence of +2 and +4, forms staimous (tin(II)) compounds and stannic (tin(IV)) compounds. Tin compounds include inorganic tin(II) and tin(IV) compounds complex stannites, MSnX., and staimates, M2SnX, and coordination complexes, organic tin salts where the tin is not bonded through carbon, and organotin compounds, which contain one-to-four carbon atoms bonded direcdy to tin. 

Transparent electroconductive coatings of stannic oxide are deposited on nonconductive substrates for electrical and strengthening appHcations. However, the agents used to deposit the oxide film are actually stannic chloride. More recently, some organotin compounds have been employed. 

These reactions proceed rapidly and in good yield with primary alkyl and phenyl organotin compounds at ca 200°C. The reactions proceed at lower temperatures if anhydrous aluminum chloride is used as a catalyst. 

Hexaorganoditins with short-chain ahphatic groups are colorless Hquids, distillable under vacuum, soluble in organic solvents other than the lower alcohols, and insoluble in water. They are generally unstable in ak, undergoing ready oxidation to a mixture of organotin compounds. Hexaarylditins are usually crystalline soHds and are much more stable towards oxidation. 

The current OSHA TLV standard for exposure to all organotin compounds is 0.1 mg of organotin compounds (as tin)/m air averaged over an 8-h work shift (192). NIOSH has recommended a permissible exposure limit of 0.1 mg/m of tin averaged over a work shift of up to 10 h/d, 40 h/wk Reference 193 should be consulted for more detailed information. Additional information on the health effects of organotin compounds is given in Reference 48. 

Commercially available tin compounds having aimual production or gross sales of >2.3 metric tons or 5,000.00 are Hsted in References 194 and 195. Principal U.S. producers of inorganic tin compounds include M T Chemicals, Inc., Vulcan Materials Company, and Allied Corporation. M T Chemicals, Inc., is the largest U.S. producer of organotin compounds, followed by Carstab Corporation, Witco Chemical Corporation, and Cardinal Chemical Company minor producers are Interstab, Synthetic Products Company, Tenneco Chemicals Company, and Ferro Chemical Company... 

In 1975, the estimated world aimual production of tin chemicals represented the consumption of 12,000—14,000 t of tin metal or 5% of total tin consumption (196). In 1978, ca 20,000 t/yr was consumed worldwide, with equal amounts represented by inorganic tin and organotin compounds (197). It is estabhshed that worldwide production of organotins rose from ca 50 t in 1950 to a possible 30,000—35,000 t in 1980. 

Table 13. Prices of Selected Inorganic Tin and Organotin Compounds, 1982 ...

Environmental Health Criteria, Uol 15 Tin and Organotin Compounds A Preliminary Review, WHO, Geneva, 1980. 

A. Sawyer, ed., Organotin Compounds, Marcel Dekker, New York, 1971. 

R. C. PoUer, The Chemistry of Organotin Compounds, Academic Press, New York, 1970. 

H. G. Kuivila in. . Zuckerman, ed., Organotin Compounds—New Chemistry and Applications, Advances in Chemistry Series No. 157, American Chemical Society, Washington, D.C., 1976, p. 41. 

P. J. Smith, Toxicological Data on Organotin Compounds, ITRI Pubhcation No. 538, International Tin Research Institute, Petivale, UK, 1977. 

Occupational Exposure to Organotin Compounds, DHEW (NIOSH) Pubhcation No. 77-115, U.S. Department of Health, Education, and Welfare, National Institute for Occupational Safety and Health, Washington, D.C., Nov. 1976. 

Organohalogenated compounds and substances which may form such compounds in the aquatic environment Organophosphorus compounds Organotin compounds... 

Toxic Reactions of the Skin Irritation is the most common reaction of the skin. Skin irritation is usually a local inflammatory reaction. The most common skin irritants are solvents dehydrating, oxidizing, or reducing compounds and cosmetic compounds. Acids and alkalies are common irritants. Irritation reactions can be divided into acute irritation and corrosion. Necrosis of the surface of the skin is typical for corrosion. Acids and alkalies also cause chemical burns. Phenols, organotin compounds, hydrogen fluoride, and yellow phosphorus may cause serious burns. Phenol also causes local anesthesia, in fact it has been used as a local anesthetic in minor ear operations such as puncture of the tympanous membrane in cases of otitis. ... 

Fig. 1 Chromatogram of organotin compounds. Dibutyltin dilaurate (1), dibutyltin dichloride (2), dioctyltin oxide (3), tributyltin oxide (4), tributyltin chloride (5), tetrabutyltin (6).

Promotes and fosters the dissemination of scientific and technical information on the environmental effects of organotin compounds. 

Perfluorovinyl organotin compounds can be prepared from perfluorovinyl Grignard reagents and organotin halides [76] (equation 11) Yields are slightly improved under Barbier conditions [76]... 

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