Tin(IV) oxide

Chemical compound known as stannic oxide, cassiterite and tin ore

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| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 441026480
| ImageFile = Rutile unit cell 3D balls. png
| ImageSize = 160px
| ImageName = 3D model of tin (IV) oxide, red atom is oxide
| ImageFile1 = SnO2powder. jpg
| ImageName1 = Sample of tin (IV) oxide
| IUPACName = Tin (IV) Oxide
| OtherNames = Stannic oxide, Tin(IV) oxide, Flowers of tin, 6.85 g/cm3 (24 °C)
| BoilingPtC = 1800 1900
| BoilingPt notes = Sublimes
| MagSus = −4.1·10−5 cm3/mol
| SpaceGroup = P42/mnm, No. 136
| Entropy = 49.04 J/mol·K
| LD50 = > 20 g/kg (rats, oral)
| PEL = none With many other names, this oxide of tin is an important material in tin chemistry. It is a colourless, diamagnetic, amphoteric solid.

Tin(IV) oxide crystallises with the rutile structure. As such the tin atoms are six coordinate and the oxygen atoms three coordinate. Hydrous forms of SnO2 have been described as stannic acid. Such materials appear to be hydrated particles of SnO2 where the composition reflects the particle size.

Tin(IV) oxide occurs naturally. Synthetic tin(IV) oxide is produced by burning tin metal in air.

Tin(IV) oxide can be used as a polishing powder, Tin(IV) oxide for this use is sometimes called as "putty powder" e. g. butyltin trichloride as the volatile agent. This technique is used to coat glass bottles with a thin (<0.1 μm) layer of SnO2, which helps to adhere a subsequent, protective polymer coating such as polyethylene to the glass. Room temperature gas sensors are also being developed using reduced graphene oxide SnO2 composites(e. g. for ethanol detection). Doping with various compounds has been investigated (e. g. with CuO). Doping with cobalt and manganese, gives a material that can be used in e. g. high voltage varistors. Tin(IV) oxide can be doped with the oxides of iron or manganese.