Organotin Oxides and Hydroxides

Aqua complexes of the ions R3Sn+ and R2Sn2+ have been studied in aqueous solution,3 5 and bipyramidal Bu3Sn(OH2)2+ (equation 9-48)6 and octahedral R2Sn(OH2)42+ (R = Me7 or Bu8) have been identified crystallographically. 

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Organotin hydroxides and oxides are easily convertible. The compounds are not easily distinguished for melting points, are often identical due to dehydration of the hydroxides. Spectroscopic evidence is required. The compounds compiled in the following Tables I65-I6T are prepared by the ensuing methods. 

Organotin esters of the oxy- and thio-acids of phosphorus can be prepared inter alia by azeotropic dehydration of a mixture of the organotin hydroxide or oxide and the acid, or by treating a tin alkoxide or tin amide with the acids, or an organotin halide with a salt of the phosphorus acid. By using different molecular ratios of the reactants, products of different compositions can be obtained. Attempts to prepare phosphites may result in an Arbuzov rearrangement to a phosphorus(V) compound (e.g. equation 13-11).47... 

Hydrolysis occurs very readily to give the organotin hydroxides or oxides, and the stannylamines must be prepared, stored and handled under dry, CC -free, conditions. The organotin derivatives of pyrrole are less sensitive, and their hydrolysis is reversible.3 Alcoholysis of the aminostannanes provides a clean route under mild conditions to the... 

Tin hydroxides and oxides are also employed for the syntheses of heteroatom-substituted organotin compounds the treatment of trifluoromethanesulfonic anhydride with bis(trialkyltin)oxides affords trialkyltin triflates (eq (142)) [137] and the reaction of trialkylchlorostannanes with thiols proceeds via trialkylhydroxystannanes to give trialkylstannyl sulfides (eq (143)) [138]. 

Amidostannanes containing the groups Sn-NC(=0)R or Sn-NS(0)2R are easier to prepare and to handle than are the aminostannanes. The acidity of the proton on nitrogen in the parent amide is now sufficient for reaction to occur with organotin hydroxides, oxides, and alkoxides (and aminotin compounds), and, once formed, the amidostannanes are less sensitive to moisture. A variety of amidostannanes is also available from the addition of Sn-0 and Sn-N bonded compounds to nitrogen heterocumulenes. 

In the environment, organotins are associated with a range of different counterions, for example, they exist as chlorides, hydroxides, or oxides. Quantification of the levels of organotins concentrates on preserving the toxic organic component and measuring this species, irrespective of the type of counterion present. Organotin determination methods are... 

Reactions with organotin oxides, hydroxides and alkoxides ... 

Hydrolysis of the tin halides gives a family of important organotin oxides and hydroxides that have attracted a lot of attention in recent years. These compounds are considered in Section 3.14.16. 

There is also no conclusive evidence that inorganic tin compounds have carcinogenic properties. However, there are data which indicate that organotin compounds (bis(tributyltin)oxide and triphenyltin hydroxide) may be tumorigenic at low levels of tin. Bis(tributyltin)oxide (2.5 mg/kg/day) and triphenyl tin hydroxide (0.3-6.2 mg/kg/day) were associated with pituitary adenomas in rats of both sexes with exposures of 104-106 weeks. When triphenyltin hydroxide was administered, the pituitary adenomas were present only in the females and contributed to decreased longevity. 

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