Organotin Chemistry - wikipedia Organotin Chemistry Organotin compounds are those with tin linked to hydrocarbons. Organotin compounds or stannanes are chemical compounds based on tin with hydrocarbon substituents. Organotin chemistry is part of the wider field of organometallic chemistry. The first organotin compound was diethyltin diiodide ( ( C H ) SnI ), discovered by Edward Frankland in 1849. The area grew rapidly in the 1900s, especially after the discovery of the Grignard reagents, which are useful for producing Sn - C bonds. The area remains rich with many applications in industry and continuing activity in the research laboratory. Contents 1 Structure of organotin compounds 1.1 Organic derivatives of tin ( IV ) 1.1. 1 Organotin halides 1.1. 2 Organotin hydrides 1.1. 3 Organotin oxides and hydroxides 1.1. 4 Hypercoordinated stannanes 1.1. 5 Triorganotin cations 1.2 Tin radicals ( organic derivatives of tin ( III ) ) 1.3 Organic derivatives of tin ( II ) 1.4 Organic derivatives of tin ( I ) 2 Preparation of organotin compounds 3 Reactions of organotin compounds 4 Applications 4.1 Biological applications 5 Toxicity 6 See also 7 References 8 External links Structure of organotin compounds Organotin compounds are generally classified according to their oxidation states. Tin ( IV ) compounds are much more common and more useful. Organic derivatives of tin ( IV ) The tetraorgano derivatives are invariably tetrahedral. Compounds of the type SnRR'RR ' have been resolved into individual enantiomers. Organotin halides Organotin chlorides have the formula R SnCl for values of n up to 3. Bromides, iodides, and fluorides are also known but less important. These compounds are known for many R groups. They are always tetrahedral. The tri - and dihalides form adducts with good Lewis bases such as pyridine. The fluorides tend to associate such that dimethyltin difluoride forms sheet - like polymers. Di - and especially triorganotin halides, e.g. tributyltin chloride, exhibit toxicities approaching that of hydrogen cyanide. Organotin hydrides Organotin hydrides have the formula R SnH for values of n up to 4. The parent member of this series, stannane ( SnH ), is an unstable colourless gas. Stability is correlated with the number of organic substituents. Tributyltin hydride is used as a source of hydride radical in some organic reactions. Organotin oxides and hydroxides Main article : Stannoxane Organotin oxides and hydroxides are common products from the hydrolysis of organotin halides. Unlike the corresponding derivatives of silicon and germanium, tin oxides and hydroxides often adopt structures with penta - and even hexacoordinated tin centres, especially for the diorgano - and monoorgano derivatives. The group Sn - O - Sn is called a stannoxane. Structurally simplest of the oxides and hydroxides are the triorganotin derivatives. A commercially important triorganotin hydroxides is the acaricide Cyhexatin ( also called Plictran ), ( C H ) SnOH. Such triorganotin hydroxides exist in equilibrium with the distannoxanes : 2 R SnOH ⇌ R SnOSnR + H O With only two organic substituents on each Sn centre, the diorganotin oxides and hydroxides are structurally more complex than the triorgano derivatives. The simple geminal diols ( R Sn ( OH ) ) and monomeric stannanones ( R Sn = O ) are unknown. Diorganotin oxides ( R SnO ) are polymers except when the organic substituents are very bulky, in which case cyclic trimers or, in the case of R = CH ( SiMe ) dimers, with Sn O and Sn O rings. The distannoxanes exist as dimers of dimers with the formula ( R SnX ) O wherein the X groups ( e.g., chloride, hydroxide, carboxylate ) can be terminal or bridging ( see Table ). The hydrolysis of the monoorganotin trihalides has the potential to generate stannanoic acids, RSnO2H. As for the diorganotin oxides / hydroxides, the monoorganotin species form structurally complex because of the occurrence of dehydration / hydration, aggregation. Illustrative is the hydrolysis of butyltin trichloride to give ( ( BuSn ) O ( OH ) ). Idealized structure of trimeric diorganotin oxide. Ball - and - stick model for ( t - Bu SnO ). Structure of diorganotin oxide, highlighting the extensive intermolecular bonding. Hypercoordinated stannanes Unlike carbon ( IV ) analogues but somewhat like silicon compounds, tin ( IV ) can also be coordinated to five and even six atoms instead of the regular four. These hypercoordinated compounds usually have electronegative substituents. Numerous examples of hypervalency are provided by the organotin oxides and associated carboxylates and related pseudohalide derivatives. The organotin halides for adducts, e.g. Me SnCl ( bipyridine. The all - organic penta - and hexaorganostannates have even been characterized, while in the subsequent year a six - coordinated tetraorganotin compound was reported. A crystal structure of room - temperature stable ( in argon ) all - carbon pentaorganostannane was reported as the lithium salt with this structure : In this distorted trigonal bipyramidal structure the carbon to tin bond lengths ( 2.26 Å apical, 2.17 Å equatorial ) are larger than regular C - Sn bonds ( 2.14 Å ) reflecting its hypervalent nature. Triorganotin cations Some reactions of triorganotin halides implicate a role for R3Sn+ intermediates. Such cations are analogous to carbocations. They have been characterized crystallographically when the organic substituents are large, such as 2, 4, 6 - triisopropylphenyl. Tin radicals ( organic derivatives of tin ( iii ) ) Tin radicals, with the formula R Sn, are called stannyl radicals. They are invoked as intermediates in certain atom - transfer reactions. For example, tributyltin hydride ( tri-n - butylstannane ) serves as a useful source of `` hydrogen atoms '' because of the stability of the tributytin radical. Organic derivatives of tin ( II ) Organotin ( II ) compounds are somewhat rare. Compounds with the empirical formula SnR are somewhat fragile and exist as rings or polymers when R is not bulky. The polymers, called polystannanes, have the formula ( SnR ). In principle divalent tin compounds might be expected to form analogues of alkenes with a formal double bond. Indeed, compounds with the formula Sn R, called distannenes, are known for certain organic substituents. The Sn centres tend to be highly pyramidal. Monomeric compounds with the formula SnR, analogues of carbenes are also known in a few cases. One example is Sn ( SiR ), where R is the very bulky CH ( SiMe ) ( Me = methyl ). Such species reversibly dimerize to the distannylene upon crystallization : 2 R Sn ⇌ ( R Sn ) Stannenes, compounds with tin -- carbon double bonds, are exemplified by derivatives of stannabenzene. Stannoles, structural analogs of cyclopentadiene, exhibit little C - Sn double bond character. Organic derivatives of tin ( I ) Compounds of Sn ( I ) are rare and only observed with very bulky ligands. One prominent family of cages is accessed by pyrolysis of the 2, 6 - diethylphenyl - substituted tristannylene ( Sn ( C H - 2, 6 - Et ) ), which affords the cubane - type cluster and a prismane. These cages contain Sn ( I ) and have the formula ( Sn ( C H - 2, 6 - Et ) ) where n = 8, 10. A stannyne contains a carbon to tin triple bond and a distannyne a triple bond between two tin atoms ( RSnSnR ). Distannynes only exist for extremely bulky substituents. Unlike alkynes, the C - Sn - Sn - C core of these distannynes are nonlinear, although they are planar. The Sn - Sn distance is 3.066 ( 1 ) Å, and the Sn - Sn - C angles are 99.25 ( 14 ) °. Such compounds are prepared by reduction of bulky aryltin ( II ) halides. Structure of an Ar Sn `` prismane '', a compound containing Sn ( I ) ( Ar = 2, 6 - diethylphenyl ). Preparation of organotin compounds Organotin compounds can be synthesised by numerous methods. Classic is the reaction of a Grignard reagent with tin halides for example tin tetrachloride. An example is provided by the synthesis of tetraethyltin : 4 EtMgBr + SnCl → Et Sn + 4 MgClBr The symmetrical tetraorganotin compounds, especially tetraalkyl derivatives, can then be converted to various mixed chlorides by redistribution reactions ( also known as the `` Kocheshkov comproportionation '' in the case of organotin compounds ) : 3 R Sn + SnCl → 4 R SnCl R Sn + SnCl → 2 R SnCl R Sn + 3 SnCl → 4 RSnCl A related method involves redistribution of tin halides with organoaluminium compounds. The mixed organo - halo tin compounds can be converted to the mixed organic derivatives, as illustrated by the synthesis of dibutyldivinyltin : Bu SnCl + 2 C H MgBr → Bu Sn ( C H ) + 2 MgBrCl The organotin hydrides are generated by reduction of the mixed alkyl chlorides. For example, treatment of dibutyltin dichloride with lithium aluminium hydride gives the dibutyltin dihydride, a colourless distillable oil : Bu 2 SnCl 2 + 1 2 LiAlH 4 ⟶ Bu 2 SnH 2 + 1 2 LiAlCl 4 ( displaystyle ( ce ( ( Bu2SnCl2 ) + 1 / 2LiAlH4 - > ( Bu2SnH2 ) + 1 / 2LiAlCl4 ) ) ) The Wurtz - like coupling of alkyl sodium compounds with tin halides yields tetraorganotin compounds. Reactions of organotin compounds Important reactions, discussed above, usually focus on organotin halides and pseudohalides with nucleophiles. In the area of organic synthesis, the Stille reaction is considered important. It entails coupling reaction with sp2 - hybridized organic halides catalyzed by palladium : R − X + R ′ − SnR '' 3 → Pd catalyst R − R ′ + XSnR '' 3 ( displaystyle ( ce ( ( R-X ) + R ' - SnR ' ' 3 - > ( ( ce ( Pd catalyst ) ) ) ( R-R ' ) + XSnR ' ' 3 ) ) ) and organostannane additions ( nucleophilic addition of an allyl -, allenyl -, or propargylstannanes to an aldehydes and imines ). Organotin compounds are also used extensively in radical chemistry ( e.g. radical cyclizations, Barton -- McCombie deoxygenation, Barton decarboxylation, etc. ). Applications An organotin compound is commercially applied as stabilizers in polyvinyl chloride. In this capacity, they suppress degradation by removing allylic chloride groups and by absorbing hydrogen chloride. This application consumes about 20,000 tons of tin each year. The main class of organotin compounds are diorganotin dithiolates with the formula R Sn ( SR ' ). The Sn - S bond is the reactive component. Diorganotin carboxylates, e.g., dibutyltin dilaurate, are used as catalysts for the formation of polyurethanes, for vulcanization of silicones, and transesterification. n - Butyltin trichloride is used in the production of tin dioxide layers on glass bottles by chemical vapor deposition. Biological applications `` Tributyltins '' are used as industrial biocides, e.g. as antifungal agents in textiles and paper, wood pulp and paper mill systems, breweries, and industrial cooling systems. Triphenyltin derivativess are used as active components of antifungal paints and agricultural fungicides. Other triorganotins are used as miticides and acaricides. Tributyltin oxide has been extensively used as a wood preservative. Tributyltin compounds were once widely used as marine anti-biofouling agents to improve the efficiency of ocean - going ships. Concerns over toxicity of these compounds ( some reports describe biological effects to marine life at a concentration of 1 nanogram per liter ) led to a worldwide ban by the International Maritime Organization. Organotin complexes have been studied in anticancer therapy. Organotin compounds Tetrabutyltin colorless oil, precursor to the other butyl - tin compounds Tributyltin oxide, a colorless to pale yellow liquid used in wood preservation Triphenyltin acetate, an off - white crystalline solid, used as an insecticide and a fungicide Triphenyltin chloride, a highly toxic white solid, used as a biocide Trimethyltin chloride, a toxic white solid, once used as a biocide Triphenyltin hydroxide, an off - white powder, used as a fungicide Azocyclotin, a white solid, used as a long - acting acaricide for control of spider mites on plants Cyhexatin, a white solid, used as an acaricide and miticide Hexamethylditin used as an intermediate in chemical synthesis Tetraethyltin, boiling point 63 -- 65 ° / 12 mm is a catalyst Toxicity Triorganotin compounds can be highly toxic. Tri-n - alkyltins are phytotoxic and therefore can not be used in agriculture. Depending on the organic groups, they can be powerful bactericides and fungicides. Reflecting their high bioactivity, `` tributyltins '' were once used in marine anti-fouling paint. Tetraorgano -, diorgano -, and monoorganotin compounds generally exhibit low toxicity and low biological activity. DBT may however be immunotoxic. See also Organostannane addition Tributyltin azide Carbastannatranes Compounds of carbon with other elements in the periodic table This box : view talk edit CH He CLi CBe CB CC CN CO CF Ne CNa CMg CAl CSi CP CS CCl CAr CK CCa CSc CTi CV CCr CMn CFe CCo CNi CCu CZn CGa CGe CAs CSe CBr CKr CRb CSr CY CZr CNb CMo CTc CRu CRh CPd CAg CCd CIn CSn CSb CTe CI CXe CCs CBa CHf CTa CW CRe COs CIr CPt CAu CHg CTl CPb CBi CPo CAt Rn Fr CRa Rf Db CSg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og ↓ CLa CCe CPr CNd CPm CSm CEu CGd CTb CDy CHo CEr CTm CYb CLu Ac CTh CPa CU CNp CPu CAm CCm CBk CCf CEs Fm Md No Lr Chemical bonds to carbon Core organic chemistry Many uses in chemistry Academic research, but no widespread use Bond unknown References Jump up ^ Caseri, Walter ( 2014 ). `` Initial Organotin Chemistry ''. Journal of Organometallic Chemistry. 751 : 20 -- 24. doi : 10.1016 / j. jorganchem. 2013.08. 009. ^ Jump up to : Davies, Alwyn George. ( 2004 ) Organotin Chemistry, 2nd Edition Weinheim : Wiley - VCH. ISBN 978 - 3 - 527 - 31023 - 4 Jump up ^ Gielen, Marcel ( 1973 ). `` From kinetics to the synthesis of chiral tetraorganotin compounds ''. Acc. Chem. Res. 6 : 198 -- 202. doi : 10.1021 / ar50066a0. Jump up ^ G.G. Graf `` Tin, Tin Alloys, and Tin Compounds '' in Ullmann 's Encyclopedia of Industrial Chemistry, 2005 Wiley - VCH, Weinheim doi : 10.1002 / 14356007. a27_049 ^ Jump up to : Chandrasekhar, Vadapalli ; Nagendran, Selvarajan ; Baskar, Viswanathan ( 2002 ). `` Organotin assemblies containing Sn / O bonds ''. Coordination Chemistry Reviews. 235 : 1 -- 52. doi : 10.1016 / S0010 - 8545 ( 02 ) 00178 - 9. Jump up ^ Reich, Hans J. ; Phillips, Nancy H. ( 1986 ). `` Lithium - Metalloid Exchange Reactions. Observation of Lithium Pentaalkyl / aryl Tin Ate Complexes ''. J. Am. Chem. Soc. 108 : 2102. doi : 10.1021 / ja00268a067. Jump up ^ V.G. Kumar Das ; Lo Kong Mun ; Chen Wei ; Thomas C.W. Mak ( 1987 ). `` Synthesis, Spectroscopic Study, and X-ray Crystal Structure of Bis ( 3 - ( 2 - pyridyl ) - 2 - thienyl - C, N ) diphenyltin ( IV ) : The First Example of a Six - Coordinate Tetraorganotin Compound ''. Organometallics. 6 : 10. doi : 10.1021 / om00144a003. Jump up ^ Masaichi Saito ; Sanae Imaizumi ; Tomoyuki Tajima ; Kazuya Ishimura & Shigeru Nagase ( 2007 ). `` Synthesis and Structure of Pentaorganostannate Having Five Carbon Substituents ''. J. Am. Chem. Soc. 129 : 10974 -- 10975. doi : 10.1021 / ja072478. Jump up ^ Greenwood, Norman N. ; Earnshaw, Alan ( 1997 ). Chemistry of the Elements ( 2nd ed. ). Butterworth - Heinemann. ISBN 0 - 08 - 037941 - 9. Jump up ^ T.V. RajanBabu, P.C.B. Page B.R. Buckley `` Tri-n - butylstannane '' in e-EROS Encyclopedia of Reagents for Organic Synthesis, 2004. doi : 10.1002 / 047084289X. rt181. pub2 Jump up ^ Holleman, Arnold Frederik ; Wiberg, Egon ( 2001 ), Wiberg, Nils, ed., Inorganic Chemistry, translated by Eagleson, Mary ; Brewer, William, San Diego / Berlin : Academic Press / De Gruyter, ISBN 0 - 12 - 352651 - 5 Jump up ^ Sita, Lawrence R. ( 1994 ). `` Heavy - Metal Organic Chemistry : Building with Tin ''. Acc. Chem. Res. 27 : 191 -- 197. doi : 10.1021 / ar00043a002. Jump up ^ Power, Philip P. ( 2007 ). `` Bonding and Reactivity of Heavier Group 14 Element Alkyne Analogues ''. Organometallics. 26 : 4362 -- 4372. doi : 10.1021 / om700365p. Jump up ^ Sander H.L. Thoonen ; Berth - Jan Deelman ; Gerard van Koten ( 2004 ). `` Synthetic aspects of tetraorganotins and organotin ( IV ) halides '' ( PDF ). Journal of Organometallic Chemistry ( 689 ) : 2145 -- 2157. Jump up ^ Der Kerk, G.J.M. Van ; Luijten, J.G.A. ( 1956 ). `` Tetraethyltin ''. Org. Synth. 36 : 86ff. doi : 10.15227 / orgsyn. 036.0086. Jump up ^ Dietmar Seyferth `` Di - n - butyldivinyltin '' Org. Synth. 1959, volume 39, page 10. doi : 10.15227 / orgsyn. 039.0010 Jump up ^ `` Organometallic Syntheses : Nontransition - Metal Compounds '' John Eisch, Ed. Academic Press : New York, 1981. ISBN 0122349504. Jump up ^ Gajda, M. ; Jancso, A. ( 2010 ). `` Organotins, formation, use, speciation and toxicology ''. Metal ions in life sciences. Cambridge : RSC publishing. 7, Organometallics in environment and toxicology. ISBN 9781847551771. Jump up ^ S. Gómez - Ruiz ; et al. ( 2008 ). `` Study of the cytotoxic activity of di and triphenyltin ( IV ) carboxylate complexes ''. Journal of Inorganic Biochemistry. 102 ( 12 ) : 2087 -- 96. doi : 10.1016 / j. jinorgbio. 2008.07. 009. PMID 18760840. Jump up ^ Organic Syntheses, Coll. Vol. 4, p. 881 ( 1963 ) ; Vol. 36, p. 86 ( 1956 ). Link Jump up ^ C Gumy ; et al. ( 2008 ). `` Dibutyltin Disrupts Glucocorticoid Receptor Function and Impairs Glucocorticoid - Induced Suppression of Cytokine Production ''. PLoS ONE. 3 : e3545. Bibcode : 2008PLoSO... 3.3545 G. doi : 10.1371 / journal. pone. 0003545. PMC 2568824. PMID 18958157. External links National Pollutant Inventory Fact Sheet for organotins Industry information site Organotin chemistry in synthesis Health issues of plastics and polyhalogenated compounds ( PHCs ) Plasticizers : Phthalates DIBP DBP BBP ( BBzP ) DIHP DEHP ( DOP ) DIDP DINP Miscellaneous plasticizers Organophosphates Adipates ( DEHA DOA ) Monomers Bisphenol A ( BPA, in Polycarbonates ) Vinyl chloride ( in PVC ) Miscellaneous additives incl. PHCs PBDEs PCBs Organotins PFCs Perfluorooctanoic acid Health issues Teratogen Carcinogen Endocrine disruptor Diabetes Obesity Obesogen Polymer fume fever Pollution Plastic pollution Great Pacific garbage patch Persistent organic pollutant Dioxins List of environmental health hazards Regulations California Proposition 65 European REACH regulation Japan Toxic Substances Law Toxic Substances Control Act Retrieved from `` https://en.wikipedia.org/w/index.php?title=Organotin_chemistry&oldid=797479132 '' Categories : Organotin compounds Pesticides Endocrine disruptors Talk Contents About Wikipedia Čeština Deutsch Español فارسی Français Bahasa Indonesia Italiano Nederlands 日本 語 Русский Suomi 中文 Edit links This page was last edited on 27 August 2017, at 08 : 53. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. 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Question: the nature of c-sn bond in alkyl tin is
Answer: invariably tetrahedral