Indium(III) hydroxide is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the formula In(OH)₃. Its prime use is as a precursor to

indium(III) oxide Indium(III) oxide ( In2 O3) is a chemical compound, an amphoteric oxide of indium. Physical properties Crystal structure Amorphous indium oxide is insoluble in water but soluble in acids, whereas crystalline indium oxide is insoluble in both wat ...

, In₂O₃. It is sometimes found as the rare mineral

dzhalindite Dzhalindite is a rare indium hydroxide mineral discovered in Siberia. Its chemical formula is In(OH)3. It was first described in 1963 for an occurrence in the Dzhalinda tin deposit, Malyi Khingan Range, Khabarovskiy Kray, Far-Eastern Region, R ...

Structure

Indium(III) hydroxide has a cubic structure, space group Im3, a distorted ReO₃ structure.

Preparation and reactions

Neutralizing a solution containing an In³⁺ salt such as

indium nitrate Indium(III) nitrate is a nitrate salt of indium. It reacts with sodium tungstate Sodium tungstate is the inorganic compound with the formula Na2WO4. This white, water-soluble solid is the sodium salt of tungstic acid. It is useful as a source o ...

(In(NO₃)₃) or a solution of

indium trichloride Indium(III) chloride is the chemical compound with the formula In Cl3. This salt is a white, flaky solid with applications in organic synthesis as a Lewis acid. It is also the most available soluble derivative of indium. Synthesis and structur ...

(InCl₃) gives a white precipitate that on aging forms indium(III) hydroxide. A

thermal decomposition Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is re ...

of freshly prepared In(OH)₃ shows the first step is the conversion of In(OH)₃xH₂O to cubic indium(III) hydroxide. The precipitation of indium hydroxide was a step in the separation of indium from

zincblende Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Va ...

ore by

Reich ''Reich'' (; ) is a German noun whose meaning is analogous to the meaning of the English word "realm"; this is not to be confused with the German adjective "reich" which means "rich". The terms ' (literally the "realm of an emperor") and ' (lit ...

and Richter, the discoverers of indium. Indium(III) hydroxide is

amphoteric In chemistry, an amphoteric compound () is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used. One type of amphoteric species are amphipro ...

, like

gallium(III) hydroxide Gallium hydroxide, Ga(OH)3 is formed as a gel following the addition of ammonia to Ga3+ salts.Anthony John Downs, (1993), ''Chemistry of Aluminium, Gallium, Indium, and Thallium'', Springer, It is also found in nature as the rare mineral söhngei ...

(Ga(OH)₃) and

aluminium hydroxide Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic an ...

(Al(OH)₃), but is much less acidic than gallium hydroxide (Ga(OH)₃), having a lower solubility in alkaline solutions than in acid solutions. It is for all intents and purposes a basic hydroxide. Dissolving indium(III) hydroxide in strong alkali gives solutions that probably contain either four coordinate In(OH)₄⁻ or In(OH)₄(H₂O)⁻. Reaction with acetic acid or carboxylic acids is likely to give the basic acetate or carboxylate salt, e.g. In(OH)(OOCCH₃)₂. At 10 MPa pressure and 250-400 °C, indium(III) hydroxide converts to indium oxide hydroxide (InO(OH)), which has a distorted rutile structure. Rapid decompression of samples of indium(III) hydroxide compressed at 34 GPa causes decomposition, yielding some indium metal. Laser ablation of indium(III) hydroxide gives indium(I) hydroxide (InOH), a bent molecule with an In-O-H angle of around 132° and an In-O bond length of 201.7 pm.

References

{{Hydroxides Indium compounds Hydroxides Inorganic compounds